Consciousness and the Physical World  


Douglas M. Stokes


May, 2006


©2007 Douglas M. Stokes


To Iris and Rachel, my closest companions in this strangest of journeys.



I would like to thank all those who have pushed, prodded and led me to construct the Person I am (even though I will be shortly arguing that this very construction is ultimately an illusion).  

These people include the faculty members of Tabor Academy (including my parents), Harvard University and the University of Michigan.  They provided me with the tools I needed to embark on this journey.  Ultimately, however, I refused to enter the dark and narrow tunnel into which these last two institutions guided me.

I am especially indebted to the editors of parapsychological journals who have guided my writing and given me a voice in parapsychology over the years, including K. Ramakrishna Rao, Dorothy Pope, Laura Dale, Betty Shapin, Rhea White, Stanley Krippner, John Palmer, Suzanne Brown and Nicola Holt. 

I would also like to thank those who have helped me formulate my views, including J. B. and Louisa Rhine, Karlis Osis, John Beloff, Susan Blackmore and too many more to mention here.  At least one will be surprised to find herself on this list.  Sometimes you learn the most from those you ideas you initially find foreign and wrong-headed.    These ideas have a way of chipping an entrance into one’s thick skull, slowly but surely.  It may take decades, but one’s inner sanctum is eventually penetrated.

I would especially like to thank Robert Franklin and the rest of the staff at McFarland books, who have provided the main avenue through which serious books on parapsychology and radical investigations of the mind-body problem could be published.  Without their efforts, these fields would be much the poorer, if they would even exist at all.   

Table of Contents

0.  Dreams and Awakenings. 3

1.  Mind and Matter 10

2. Mind and the Quantum.. 24

3. The Evidence for Psi: Spontaneous Phenomena. 30

4. The Evidence for Psi: Experimental Studies. 56

5. The Implications of Psi 77

6. Death and the Mind. 110

7.  The Nature of the Self 140

8.  The Self Writ Large. 151

9.  A Summing Up. 161

Bibliography. 162



This is a book about the self, the soul as it were (to use two terms with all the wrong connotations).  It argues for the view of the self as a field of pure consciousness or “Cartesian theater” (to use the dismissive terminology of Daniel Dennett).  It draws conclusions about the self and its relations to the physical body and the physical world that the reader may find unorthodox and surprising.

This book will explore many familiar areas in a hopefully unfamiliar way.  These areas include the perennial mind-body problem, the role of consciousness in quantum mechanics, the anthropic principle, the evidence for Intelligent Design, and parapsychology (the investigation of ostensible paranormal abilities such as ESP and psychokinesis).

This book retraces many of the themes of my earlier book The Nature of Mind (Stokes, 1997) and in places may be regarded as an updating of that book.  It also contains a comprehensive updating of my chapter on theoretical parapsychology in Stanley Krippner’s Advances in Parapsychological Research series (Stokes, 1987).  However, the central focus in the present book is much different from that in these two earlier works, as are the ultimate conclusions drawn. 

The central themes are introduced in Chapter 0, which may be regarded as the real introduction to the book; these themes then are expanded in more detail in the remaining chapters.

The reader may find the ultimate conclusions drawn to be unsettling and disconcerting, as did I in arriving at them.  Once they begin to hack their way into your brain, however, they may provide you with a sense of peace greater than that offered by the dogmas hawked by religions that are still mired in the concept of the Person.

Postscript added on August 6, 2007

A condensed and abridged version of this manuscript was published by McFarland in 2007 as The Conscious Mind and the Material World: On Psi, the Soul, and the Self.  This original manuscript contains a complete updating of my previous book The Nature of Mind as well as of my chapters on theoretical parapsychology and spontaneous psi experiences in Volumes 5 and 8 (respectively) of Stanley Krippner’s Advances in Parapsychological Research series (all three of these books were also published by McFarland).  I would encourage readers of this work to also read the aforementioned book The Conscious Mind and the Material World, as it presents a more streamlined (and updated) development of the central themes in this manuscript. 


0.  Dreams and Awakenings 

The Dream of Matter

You are born into the world as a blob of protoplasm, the astronomically improbable result of a random recombination of genes and the confluence of a (literal) uncountable infinity of random events.  Had just one or two of these billions of random events had a different outcome, you would in all likelihood never have been born.  Your very existence could not be more improbable.

 You are nothing but your body and brain. Your inner self, your aspirations and strivings, your deepest emotions, and innermost thoughts are nothing more electrical discharges and chemical secretions in the wetware of your brain.  When that brain and body are gone, decomposed once more into their constituent elements, dispersed back into the Mother Earth, and finding new homes in her countless new creatures, plants and minerals, you will be no more. Aside from your works, influences on others, and the continuation of the all the myriad other causal chains in which you once participated, it will be as though you never existed.  

 Such is the dream of modern science and indeed of many modern enlightened religions that, perhaps prematurely, have rushed to embrace the materialist worldview of modern science, not wanting to be left behind in the dark ages from which they sprang.  

Awakening From the Dream of Matter

According to the physicalistic philosophies underlying modern science, one’s self is nothing more than one’s physical body and the physical world is all that exists.  We are identical to our physical bodies, our selves nothing more than the electrochemical activity of billions of neurons housed in calcium skulls.  In the Weltanschauung of modern science, the world/universe is comprised of a collection of blindly careening elementary and not-so-elementary particles, a spacetime stage for them to perform their antics in, and little else.   The behavior of these material particles is governed by the mathematical laws of physics and nothing else.  

But, if each of us does have a self that endures from moment to moment, from day to day, and year to year (however much it may be extinguished at death), then that self cannot be identical with any specified collection of material particles.  The material particles that make up our bodies are constantly changing.  Atoms and molecules are continually entering into and exiting from your body, so that the collection of material particles that comprises your body of today is a completely different assemblage of material particles from that which comprised your body of several years ago.  Yet you perceive that you are the same self you were then.  If this perception is correct, then you cannot be identical to any particular collection of material particles, including your present physical body.  

If each of us is identical with his or her physical body, it is most surprising that we would find ourselves conscious at the present moment of time.  A human lifespan is only several decades long. On the other hand, the universe has existed for approximately 13.5 billion years and will likely exist for billions more to come (to say nothing of the age of any “multiverse,” of which the universe may be only a part).  Thus, the probability that the moment in time that has somehow been mysteriously selected to be the “present” (something that physics, by the way, has no explanation whatsoever for) would correspond to a moment in one’s lifetime would seem to be vanishingly small.  Also, if one is to be identified with a particular physical body, the probability that the set of genes that formed the blueprint for that body would ever have come into combination is virtually zero (and still smaller is the probability that the particular configuration of material particles that comprises one’s present physical body would ever have formed, much less exist at the present moment).  Yet here you find yourself (a field of consciousness that is unique and special to you at any rate) existing at the present time.  This is most surprising (indeed virtually impossible) based on the view that you are identical with, or dependent on, the presence of a particular collection of material particles at a particular moment in time.   Hence, by a quick pseudoapplication of Bayes’ theorem in statistics, the probability that the standard view (that you are your physical body) obtains is also virtually zero.  

There is much merit in the worldview of modern physical science and its current avatar is supported by a wide array of scientific evidence.   However, scientists seem always to wish that their work is complete and that leisurely island life is only just around the corner.  Sometimes they are quite adamant in their defense of this position. 

This attitude is exemplified in a statement by the Nobel prize-winning physicist Albert Abraham Michelson, which he made twenty years after his paradigm-shaking experiment on the velocity of the Earth relative to the luminiferous ether.  Michelson’s experiment (conducted in collaboration with Edward W. Morley) established the speed of light as a fundamental constant of nature and eventually led to the downfall of Newtonian mechanics and its replacement with Einstein’s special theory of relativity.  Michelson’s remarks are as follows:

The more important fundamental laws and facts of the physical universe have all been discovered and these are now so firmly established that the possibility of their ever being supplanted in consequence of new discoveries is exceedingly remote [quotation taken from Feuer, 1974, p.253].

Michelson added that, although there were apparent exceptions to most of these laws, these were due to the increasing accuracy of measurement made possible by modern apparatus and that the system of known physical laws would be adequate to deal with the “apparent exceptions.” He went on to assert that “Our future discoveries must be looked for in the sixth place of decimals” (Feuer, 1974, p. 254.)  What is most amazing about these statements is that they preceded rather than followed the publication of Einstein’s paper on special relativity, a paper that caused a revolution in science and that received its main immediate empirical support from the results of Michelson’s own experiment.  The development of quantum mechanics was another major revolution Michelson did not anticipate.  

In fact, the discoveries and revolutions just keep on a-coming. For instance, Science’s “Breakthrough of the Year” for 2003 was the discovery that 96% of the energy in the universe is comprised of dark matter and dark energy, the existence of which was not even suspected a few decades ago, rather than the matter-energy that is visible to us, which comprises a mere 4% of the energy in the universe.  A full 73% of the universe is comprised of dark energy, the existence of which was not even suspected until 1998 (Seife, 2003).  Many more surprises may be in store for us.

There is no real place for mind or consciousness in the great World Machine of modern physicalistic science (leaving aside for the moment certain interpretations of quantum mechanics, which will be discussed in more detail in Chapter 2 and elsewhere in the book).   Indeed, physicalistic science is at a loss to explain how the human brain, composed like everything else of supposedly insensate matter, can give rise to conscious experience (as contrasted with mere information-processing).  To be sure, modern cognitive neuroscience has achieved remarkable insights into the nature of the brain activities that are associated with various forms of cognitive experience.  What it has not thus far achieved is any explanation of how a three-pound hunk of meat can give rise to conscious experience in the first place.

Finally, there is a smattering of (hotly contested) evidence that conscious minds have powers such as precognition, telepathy and psychokinesis (collectively referred to as psi) that cannot be accounted for in terms of the known principles of physics.  This evidence will be discussed in detail in Chapters 3 and 4.  As modern science clings to the delusion that its grasp of the nature of reality is complete, it has steadfastly resisted the work of parapsychologists.  

Such an attitude is evident in the following comments of two eminent scientists, the psychologist Donald Hebb and the physicist Hermann von Helmholtz, regarding the early experimental work on psi phenomena conducted by J. B. Rhine at Duke University.  Rhine is generally regarded as the “father” of experimental parapsychology (the study of psi phenomena) and was the person who coined the term “extrasensory perception” (or ESP for short).  

Both quotations are taken from Collins & Pinch (1979, p. 244).  First Hebb:

Why do we not accept E.S.P. as a psychological fact? Rhine has offered us enough evidence to have convinced us on any other issue … I cannot see what other basis my colleagues have for rejecting it … My own rejection of [Rhine’s] views is in a literal sense prejudice.

Now Helmholtz:

I cannot believe it. Neither the testimony of all the Fellows of the Royal Society, not even the evidence of my own senses would lead me to believe in the transmission of thought from one person to another independently of the recognized channels of sensation. It is clearly impossible.

If psi phenomena are real, they have major implications for our understanding of the place of mind in the cosmos.  Psi phenomena appear to transcend spacetime separations and to violate the normal temporal ordering of causation (such as in the case precognition, or the ability to foresee the future, and retroactive psychokinesis, or the ability to influence events that have already occurred).  Because of their importance, a large portion of this book will be devoted to a discussion of psi phenomena and their implications for our understanding of the mind and the cosmos.  As they appear to represent phenomena that cannot be accounted for in terms of current theories of physics, psi phenomena have often been taken as pointing to the existence of an “immaterial” mind.  Many parapsychologists believe that psi phenomena may eventually be given an account in terms of an extension of current physical theories.  If so, psi phenomena may point to the existence of new physical entities and principles rather to an immaterial realm.

As we shall see, the existence of psi phenomena has not been conclusively established.  If the critics are correct and psi phenomena do not exist, the principal conclusions in this book regarding the nature of the conscious self will not be invalidated.  For instance, our recent awakening from the Dream of Matter was achieved without the “alarm clock” of psi.  Whether psi phenomena exist or not, our conscious selves cannot be identified with our physical bodies or brains.   

 The Dream of the Person

You are your mind, not your body, not even your brain.  You are your thoughts, your personality, your memories, your emotions.  In short, you are a person, not a blob of pulsating neurons.  While your body and brain might decay into dust, you may survive by being:

  1. Brought to Heaven (or Hell, Valhalla, Hades or the Dreamtime) in an angelic (or demonic) ethereal body,

  2. Reincarnated with some of your memories, emotions, thoughts and much of your personality intact, at least at a subconscious level,

  3. Transformed into an astral ghost capable of monitoring the events in this work and, occasionally, manifesting yourself to living,

  4. Resurrected in your present body or a replica thereof at the time of the Day of Judgment, or

  5. Transferred to a cybernetic “brain” by having your memories, thoughts and personality traits downloaded into a supercomputer or robot, or perhaps etched into the neuronal connections of willing or non-so-willing volunteers (or possibly even a mass of stem cells growing in a beaker in some remote laboratory). 

At any rate, there is hope for eternal life, at least if the Cosmos’s neuro-copying equipment and file retrieval systems are up to the task and do not go on the blink and if some Agent is sufficiently enamored of one’s personality to want to keep a copy of it on hand for eternity (or barring that at least until the heat death of the universe).

The first and fourth alternatives above are subscribed to by certain adherents to the Judeo-Christian-Islamic religious tradition, as well as the great mythological traditions of the pre-Christianized world, who look forward to reunion with the deity (or deities) and loved ones in some type of post-mortem realm such as the Christian Heaven.  In the fourth alternative above, the resurrection is thought to take place right here or Earth or in some Resurrection World in a parallel universe.  Besides having one’s personality recreated, we will all be generously provided with idealized resurrection bodies as well (see Edwards, 1997, pp. 53-62 for an entertaining discussion of beliefs regarding the resurrection of the body within the Christian tradition).   Many resurrectionists believe that these will be the same physical bodies we occupied in life (although as noted above, each of us has already occupied several different physical bodies).  If this is the case, I hope will not have to fight with the likes of Socrates and Jack the Ripper over who owns a particular set of atoms that we shared during our respective physical lives.  (It is estimated that every minute, each of us inhales an atom once expelled in Julius Caesar’s dying breath.)  Thus, this process of sharing recycled atoms might well result in a heated game of “musical atoms,” much like musical chairs, at the time of the resurrection.  Thus, the resurrectionists are not only lost in the Dream of the Person, they are still lost in the Dream of Matter.

The third alternative, reincarnation, is subscribed to by many shamanistic traditions, by Eastern religious traditions such as Hinduism and Buddhism (although as well shall see later, many of the more sophisticated adherents to the Eastern religious tradition have awakened from the Dream of the Person), and by as much as one-quarter of the people in the highly-Christianized United States.  There is even empirical evidence for reincarnation in the form of children who report seemingly accurate memories of past lives (Stevenson, 1987).

Additional empirical evidence for the survival of the person has been provided by psychical researchers studying apparitions and hauntings, purported massages from the dead communicated by mediums or in dreams, as well as near-death experiences and the related phenomenon of out-of-the-body experiences.  A few other lines of investigation are highly amusing if not outright silly, such as attempts to detect messages from the dead in radio static or on one’s phone answering machine and to weigh and/or photograph the soul upon its departure at death.  We will duly consider this evidence empirical evidence for the survival of the personality in Chapter 6, presenting both the proponents’ and skeptics’ evidence and arguments. 

As for the fifth alternative, some writers, including Hans Moravec (1988), Grant Fjermedal (1987), and Frank Tipler (1994) among others, have suggested that one’s thoughts, memories and personality could be “downloaded“ into a computer or robot, allowing one’s essential self to survive after death in a cybernetic world or as a cybernetic simulacrum operating in the physical world.   This survival could be for eternity, or at least until the heat death of the universe (after which the universe may not be that much fun to play in anyway).

Awakening from the Dream of the Person

   Just as the collection of atoms and elementary particles making up your physical body undergoes continual change and replacement, so do your thoughts, emotions, memories and personality traits.  Your essential self persists, despite these continual changes in the contents of your consciousness (and, we might add, subconscious and unconscious minds as well).  Thus, you cannot be your personality or its “contents,” such as your thoughts, emotions, and memories.

During the past three decades neuroscientists have amply demonstrated that one’s sensations, feelings, thoughts, emotions, memories, ideas, and even personality can be radically altered through electromagnetic, surgical, chemical, and accidental interventions in the brain.  Thus, we live in a different world of knowledge than did the psychical researchers of a century ago, who searched for some trace of the continuing existence of the dearly departed in the garbled words of mediums uttered during séances.

If relatively minor modifications of brain states can substantially alter the nature of one’s experience and personality, as has by now been amply demonstrated, how could your personality and experiences manage to continue on in a more or less an uninterrupted fashion after the far more drastic event of the destruction of your entire brain?  Also, many of the concerns that drive the structure of your personality have to do with the preservation of your own physical body and those of people who are closely related to you (or perhaps to the propagation of your “selfish genes”).  What would be the point of the continuance of these concerns once your physical body has been returned to dust and your ability to intervene in the physical world perhaps radically curtailed?

Of course, there is the possibility, as suggested by Tipler (1994), that your personality may be resurrected by a benevolent and almost omnipotent Programmer that is so enamored of you that She creates a simulacrum of your personality in a semi-eternal cyberspace.  However, there is nothing in principle stopping a sufficiently ardent Fan of your personality from constructing a computer or robot to simulate your personality while you are still alive.  Surely it would be absurd to think that your self would then reside both in the computer and in your physical body.  The computer or robot is just a replica of you.  It is not you.  You are not your personality traits and behavior patterns. 

Along similar lines, it could be argued that, if you are not the particular collection of physical particles that make up your present physical body, perhaps you are the particular pattern of molecules that make up your present body (including your brain configuration and thus personality).  You would then remain the same person even if the physical particles that make up your body changed, so long as the general pattern remained the same. This is the basis of the famous beaming technique in the Star Trek television and movie series.  In Star Trek, one can “beam” to a new location by undergoing a process in which one’s physical body is atomized, information about the pattern of the physical particles that make up one’s body is sent to a distant location, and a new body is reassembled (presumably out of new atoms) at the second location. Peter Oppenheimer  (1986) and Derek Parfit (1987) have independently concluded that this beaming process would result in the death of everyone who used it as a form of transportation, followed by the construction of a replica of the person at the destination site. This replica may not be the original person any more than identical twins are the same person as one another. To make this example more compelling, assume that more than one copy of the person is assembled at the destination site.  Surely it would be difficult to believe that one’s self could simultaneously inhabit all the replicas of one’s physical body that are constructed at the destination site, insofar as a conscious self cannot have several separate and independent streams of consciousness occurring at the same time.

Thus, you cannot be the pattern of your neural activity, your emotions, your memories, your personality traits, or your present hopes and dreams.  We have now awakened from both the Dream of Matter and the Dream of the Person.   If we are not our physical bodies and not our personalities, then what can we be?  What further dreams await us?

The Dream of Atman and Brahman

The self that (seems to) persist over long time periods (from birth to death in the popular, common view) would appear to correspond to what Hornell Hart (1958) called the “I-thinker,” that entity that thinks one’s thoughts (although it may not have a primary role in generating them), feels one’s feelings, remembers one’s memories and senses one’s sensations, rather than being the conglomeration of the thoughts, feelings, memories, and sensations themselves.  After all, these contents of consciousness are fleeting and do not persist from one moment to the next.  One outlives one’s current emotional state, and one’s self may survive the demise of myriad personalities.  After all, how could we be the contents of our streams of consciousness when these contents change from moment to moment while we ourselves seem to persist unchanged from moment to moment, day to day and even from year to year? 

What seems to persist, at least from an introspectionist point of view, is the (contentless) field of consciousness itself.  Perhaps, as suggested above, our real selves are fields of pure consciousness, the “contentless consciousness” of Indian philosophy, as described by Rao (2002), among others.  In other words, we are the vessel of consciousness rather than the contents of that vessel.  

After all, how could we be the contents of our consciousness when such contents change constantly while we seem to persist unchanged from moment to moment, day to day, and even from year to year? It is one of the goals of Buddhist meditative practice to realize that one’s emotions, one’s cravings, and one’s personality are not oneself, to realize oneself as a center of pure consciousness and to extinguish the cravings and clingings that cause discontent and suffering. Similarly, in the Vedantic tradition of Hinduism, one of the ultimate goals in spiritual development is to realize the identity between Atman (one’s individual consciousness) and Brahman (the World Consciousness, or, to use a potentially misleading term from the Western tradition, God).  Under the Vedantic worldview, there is only one pure consciousness, and we are all the Universe looking at itself from different perspectives.

Of course there are those, such as Daniel Dennett (1991), Susan Blackmore (1991a, 1993, 2002) and Thomas Metzinger (2003), who deny the very existence of a continuing self, or “Cartesian theater,” as Dennett calls it.  The self, they maintain, is a convenient “story” we tell ourselves in an attempt to render our experiences coherent and consistent.  As such, the self is an entirely fictional concept, and “we” are nothing more than the scattered contents (fleeting sensations, thoughts, and emotions) of “our” minds.  To most people the existence of a continuing self is immediately given and obviously true. It is an integral part of our essential existence.  However, if thinkers such as Blackmore and Dennett are correct, there is no need to worry about whether the self will survive death.  Indeed, the “self” does not even survive moment to moment and in fact does not even exist at all. 

The Zen doctrine of “No Mind” also denies the existence of a continuing self.  However, the Buddhist doctrine seems more directed at the concept of the self as one’s personality, comprising one’s aspirations, motivations, cravings for material possessions, lusts, pride, and so forth, rather than at the existence of a field of pure consciousness.  A goal of Buddhist practice is to distance oneself from these transitory elements. In order to achieve a state of peace and tranquility, the Buddhists teach that one must suppress and eliminate one’s cravings and greed, which, unfulfilled, are the root of all human misery and suffering.  

As we have seen above, most branches of Buddhism and Hinduism teach that the true self is pure consciousness, not the contents or objects of consciousness.  Thus, rather than clinging to the hope that one’s personality will survive relatively intact in some sort of afterlife, the Eastern philosophies teach that our personalities are transitory and not our true selves.  One’s true self in this view is the pure consciousness that in Hindu philosophy is taken to be identical with all consciousness, including that of the World Soul or Brahman. Under the Vedantic worldview, there is only one pure consciousness, and we are all the Universe looking at itself from different perspectives.  Thus, according to this view, when persons temporarily abandon their individual identities and perceive themselves as merging with the Cosmos or as being in perfect union with God, as in the mystical experiences described by William James (1902) and others, they are seeing directly into their true selves.  All consciousness is the one Consciousness that underlies this and all other worlds.  We are fragmented splinters of the World Soul, our selves at once separate from, and yet identical to, one another.

It should be conceded that survival in the form of pure consciousness with little continuity of memories, emotions, and predispositions from one’s previous biological life may not be what most persons would consider survival in the true sense (i.e., survival with one’s memories and personality completely intact).  It would, however, be survival of one’s essential self, the central core of one’s existence.

If our true self is Atman, pure consciousness, is there any Brahman, any larger Consciousness for it to merge in, or be identical with?   In recent times, most scientists have turned their backs to the concept of Deity and a Creator, with the possible exception of such doddering old “fools” as Erwin Schrödinger and Isaac Newton.  Arguments for a Designer have largely been abandoned as regressive.  After all, if there was a Designer, who designed Him?  If there was a “preuniverse,” then what preceded that?

The noted mathematician and physicist Sir James Jeans, pondering the subtleties of the mathematics of laws of physics and the seeming dependence of material events upon observation by conscious minds, observed, that the “universe begins to look more like a great thought than a great machine” (Jeans, 1937, p. 122).  Another great physicist, Sir Arthur Eddington, remarked, “the stuff of the world is mind-stuff” (Eddington, 1920/1959, p. 200). 

Indeed, the base reality of the world appears to be one of quantum probability waves inhabiting an abstract, multidimensional mathematical space rather than the solid, marble-like electron and protons zipping around in a four-dimensional spacetime continuum that we imagine to be the firm underpinnings of our material existence.  The mathematical complexity and beauty of the laws of the quantum mechanics are remarkable.  It does indeed seem as though the Creator is, as both Jeans and Einstein thought, a great mathematician.  As Henry Stapp says, under quantum mechanics, the world has “an essentially  ‘idea-like’ structure” (Stapp, 2005a, p. 73).  Stapp’s remarks are echoed in a recent editorial in Nature, the flagship journal of orthodox science, in which Richard Conn Henry points out that modern physics has demonstrated that the universe is “entirely mental” in nature and that “nothing exists but observations” (Henry, 2005, p.29).

But if the universe is a thought, whose thought is it anyway?  In recent years, a seemingly endless succession of physicists have observed that the laws of the universe and the initial conditions set at the time of its creation seem extraordinarily finally tuned to support the evolution of complex life forms and hence conscious observers (see Barrow & Tipler, 1986, or Livio and Rees, 2005). This seeming evidence of intelligent design is often referred to as the anthropic principle.  Was the universe created as a vast cosmic amusement park? And why go to trouble of designing such an elaborate “roadside attraction” unless One intended to enjoy it Oneself, if only vicariously? Are our individual consciousnesses just aspects of the Creator’s (or Creators’) consciousness, lost in an unimaginable form of contemplation of the myriad creatures It has managed to generate from Its mathematical inventions, much as we may become lost in the adventures of a goldfish in the bowl in our living room or in the adventures of the cybernetic “life” forms we may create when we implement the mathematician John Conway’s “Game of Life” on our computer?

The anthropic principle is based on the observation that the laws and initial conditions of the universe must be extremely fine-tuned to support life as we know it (i.e. carbon-based life forms).  But there may be other forms of life (e.g., nucleon-based) that may arise under different conditions.  Also, there may be multiple universes created, so that we necessarily find ourselves in a universe capable of supporting conscious observers, with initial conditions and laws that would seem improbable had only one universe been created with a random assortment of physical laws and initial conditions.  Guth and Kaiser (2005), for instance, note that cosmic inflation (the currently favored model of cosmogenesis) may produce “pocket universes” in each of which the fundamental laws of physics might be different.  Again, we of necessity inhabit a pocket universe that is capable of supporting the existence of conscious observers.  Still, one must explain the laws and initial conditions that gave rise to cosmic inflation in the first place.

One might imagine that a consciousness so complex and vast as to be able to create (perhaps literally dream up) such a startlingly wonderful (and frightening) world as this one might well become bored with its omniscience and may wish to lose itself in its creation, if only temporarily.  It may need to fragment itself and temporarily shed much of its omniscience to accomplish this. We too might well begin to stagnate and become bored if we were to somehow become immortal and become trapped in our present bodies and mired in our present personalities and situation for all eternity.  Death may be the rope thrown to free us from the quicksand of our current identities. 

Beyond the Veil of Maya

We awake from the Dream of Atman and Brahman to find ourselves in still yet another, but this time possibly the final, dream.  We are, exactly as in the dream from we have just awakened, each of us specks of consciousness adrift in a universe whose vastness defies our understanding (if we can even be said to have an “understanding” in any real sense of the word).  There are as yet no planets, no stars, only a rapidly expanding rush of matter and light.  The universe is but only seconds old.  We may have come from a place before the universe, but being disembodied with no notepad or brain on which to record and preserve the events of this prelife, our memories of such a place are lost.  For all we know, and we don’t know much at his point, we may have just been fused together in some great computer of our own construction, of unimaginable computational and physical power, in a “Manhattan project” designed to produce a very Big Bang indeed (at least from our perspectives).   We are adrift in a rapidly expanding spacetime designed to captivate us in a way that is even more amusing and terrifying than Hollywood concoction our current primitive technologies can produce.  However, that all lies in the distant future.  Now, with our memories lost along with our cosmogenic computer, we drift among the beautiful clouds of quantum waves, admiring their beauty, touching them, drawing them this way and that as the potential universe is actualized.   Our consciousness is like that of a quark lost in a swarming buzz of photons and gluons

As Tim Hill points out in a recent letter to the Editor of the Skeptical Inquirer (Hill, 2005), the vast emptiness of space is totally hostile to human observers with its lack of air, pockets of intense radiation and unimaginably high temperatures, not to mention the total absence of fast-food establishments.  If the anthropic principle is valid, Hill suggests, the overwhelming evidence surely suggests that the universe was created for beings that exist in the vacuum of space, not for the amusement for a handful of abnormally smart “geek” apes confined to one tiny speck in a cold dark corner of a comparatively uninterested and desolate cosmos.

Perhaps then, we are more akin to antiprotons than to angels, small islands of consciousness born to force the amorphous clouds of quantum possibilities into the crystalled raindrops of actualized events.    In the view of many interpreters of quantum mechanics, observation by consciousness is what causes such quantum collapse (i.e., collapse of the state vector containing an array of possiblities into one definite outcome).  Walker (2000) has even proposed the existence of “mini-consciousnesses” or “proto-consciousnesses” that govern the collapse of quantum vectors that are remote from human observers.  

Indeed, some physicists (e.g., Wheeler, 1983) have suggested that the universe itself, conceived as a quantum process, could not have come into existence without some conscious observer to force the collapse of state vectors and thus to give rise to a definite history of the universe.  Wheeler terms this view the “participatory universe.”  Wheeler notes that this view may explain the fact that the initial state and physical laws of the universe seem finely tuned to support the existence of conscious observers.  Potential universes that do not support the presence of conscious observers could not become actualized in Wheeler’s view, as there would be no conscious observers to collapse their state vectors in the proper “direction” to create such a history.

But perhaps those observers are more akin to Walker’s “proto-consciousnesses" than to human beings.  If physics suggests anything, it is that the fundament constituents of the universe are more likely to very small in comparison to the human observers that formed the center of the medieval view of the cosmos.  Our essential selves are more likely to resemble an electron than a human body.

After our dispersal at the time of the Big Bang, we have surfed the quantum waves, finding our selves in neutron stars, methane oceans on moons of gas giants, exploding in supernovae (the matter comprising our physical bodies was formed in such explosions), shooting out of volcanoes, condensing into rocks, sheparding the bodies of amobea, gazing out of worried eye of a stegosaur, stretching with the leaves of a sequoia.  Through much of this, our consciousness would be dim, as we float in a universe largely separated from our fellow monads, deprived of any physical template to hold our memories or any hormones to drive our wishes and aspirations.  But time is on our side.

As the debris of supernovae cooled and their ashes condensed once again into stars and planetary systems, on one remote outpost (and probably on a virtual infinity of outposts), the physical templates (and the complex assemblages of our essential selves) grew more complex.  With the first protozoa, we began to gather, and after eons we were collected in assemblages in whales and crows and octopodes and in at least one malcontented bipedal ape.

Our common conception, and one that forms part of the Dream of Atman and Brahman is that we are each a single conscious self (field of consciousness) which in some mysterious manner became attached to our brains shortly after our conceptions and will persist in those brains until we die.  But our brains are powerful and unimaginably large in comparison to our single-celled ancestors, who, we might suppose, had the glimmerings of consciousness.  Our brains and bodies are in essence a colony of billions of amoebas.  Many of us may ride in a single brain.  Indeed (as discussed in more detail in Chapter 7), when a human brain is split into its two hemispheres by severing the corpus callosum (the primary bundle of neural fibers connecting the two hemispheres), two fields of consciousness seem to exist, sometimes with such differences in motivation that the right hand (controlled by the left hemisphere) may forced to grab the left hand (controlled by the right) in order to prevent the latter from carrying out an assault on one’s spouse. 

In fact, the findings of split-brain research are precisely the evidence Patricia Churchland uses to refute the existence of a nonphysical self or soul in human beings (Churchland, 2002, pp. 46-47). 

Churchland is likely correct so far as the “single soul” theory goes; but the evidence suggests that multiple centers of consciousness or “souls” may exist within a single brain, with each of them falling under the delusion that they are the single center that is “in charge of” the body.  Jonathan C. W. Edwards (2005) and Willard Miranker (2005) have even proposed that that each single neuron in the brain is associated with its own center of consciousness.  Due to the complexity of the input to each neuron, each such center of consciousness would likely identify with the body as a whole and fall under the delusion that it is the single center conscious self “in charge” of the whole body.

We directly experience ourselves as a single unified fields of consciousness that persist through changes in our brain states and bodily composition over periods of at least hours. We think we persist as the same selves over the lifetimes of our bodies.  In this we may be wrong.  If memories are, as an overwhelming body of scientific evidence indicates, stored as patterns of synaptic connections among neurons in our brain, how do you know that you are the same field of consciousness that inhabited your body when you fell asleep?  If you can become attached to your brain shortly after conception (or in the view of some people at birth) and become detached from it at the moment of death, it stands to reason that you can also become attached to it long after birth and leave it well before death.  Our association with our bodies may be only temporary.  We may be breathed out and breathed in like so many oxygen atoms.  Indeed, while many philosophers (such as Descartes) have thought that minds or souls are not extended in space and time and hence immaterial, the fact that we find ourselves stuck in physical bodies occupying in particular locations in space and (even more mysteriously) located at a particular moments in time, suggests that we too must (at least partially) be residents of spacetime ourselves, if only temporarily.  

Elementary particles such as electrons and quarks may become embedded in physical brains; these particles persist and remain stuck over “long”  time intervals such as minutes and hours. These particles appear, like our individual consciousnesses, to be indivisible (leaving aside the possibility of subquarks for the moment).  If an electron can “incarnate” in a body for a period of time, then be expelled, and then be “reincarnated” in another body or physical system, then so might we.   We may ourselves be material or quasi-material entities that can become stuck in individual brains on a temporary basis.  We may be a particle or field already known to physical science, although it is more likely we are an entity yet to be discovered and explained.  In the latter case we could be called “nonphysical” or “immaterial” in the sense that we are not identical to any particle or field already known to modern physics; however, if the theory of physical science were to expand to accommodate us, perhaps the label of “physical” could then be applied to us.   As Noam Chomsky once remarked, as soon as we understand anything, we call it physical; thus, “anything in the world is either physical or unintelligible” (Lipkin, 2005, p. 55).

The evidence for psi phenomena, to be discussed in Chapters 3 and 4, suggests that the mind may have abilities that transcend those of entities located at single spacetime location.  Such spacetime transcendence, if proven, may make the label “physical” more difficult to apply to minds (but not impossible, in view of the nonlocal behavior of material particles under the theory of quantum mechanics, to be discussed more fully in Chapter 2).

If we are continually being recycled, then when we wake in the morning, we may not be in the same bodies (or objects or plasma fields) that we were in the day before.  If, as the overwhelming body of modern research in neuroscience indicates, our memories, thoughts and emotions are largely a function of our brain states, we would not remember our existence as, say, a crow the day before.  Our previous “memory pad,” namely the crow’s brain, is lost to us.  We cannot find those memories in the same way that we cannot access a telephone number written on a misplaced piece of paper.  The telephone number and the pad it was written on are not parts of our essential selves.   Neither are we the memories stored in the stored in the brain of the crow that now perches outside our window or the memories and personality traits stored in the new human brain in which we have just awakened. What we will remember are the memories stored in that new human brain (sometimes after a period momentary of confusion upon awakening).  We will feel the emotions caused by the intense firing of our midbrain neurons and the hormones and neurotransmitters rampaging through our cerebral cortex.  Accessing the brain’s memories of our sixth birthday party, we will immediately come to the conclusion that we have inhabited this brain and body for decades.  The brain has evolved to serve the body and we now made to serve that purpose as well, overwhelmed by the delusion that we are the Person, that is to say, the body and the memories, thoughts and emotions that result from the neural activity of that body’s brain.  We think we are in sole command of the body, whereas in fact our nerves, the neurochemical soup in which they bathe, as well as numerous other centers of pure consciousness also mired in the same brain, may have as much or more to say about the fate of the body than we do.  In short, we fall under the illusion that we are the Person, the physical body that continues from birth to death, and the stream of memories, thoughts and emotions that courses through it, rather than the centers of pure consciousness that we are.  Blackmore and Dennett are correct in their analysis that the “person” is just a story that we tell ourselves (although it would be more accurate to portray it as a story that is screamed at us by a billion pulsating neurons).  Where Blackmore and Dennett err is in denying that there is any self or center of conscious that persists from moment to moment (i.e., a “Cartesian theater”).  The existence of a conscious self is given to each of us in our direct experience (or at least to me - I can’t speak for Blackmore and Dennett).  If I am to doubt that I am a center of consciousness persisting through macroscopic time intervals, then I must doubt everything and enter a state of total solipsism and nihilism.  However, I do agree that it is likely that spheres of consciousness are, just like electrons and quarks, continually being recycled, joining first one aggregate body and then another.  We are somehow stuck to our brains like an oxygen atom stuck to two hydrogen atoms, a view I once called the “chewing gum” theory of personal identity (Stokes, 1988).  But it is likely that such centers enter and leave the brain at times other than birth and death.  The idea that the conscious self enters into the body at some time shortly after conception and then persists in that body until death is just an aspect of the illusion produced by identifying ourselves as the Person.  We are not the Person, we are not even Atman (in the sense of a sphere of pure consciousness inhabiting the body from birth until death), and are likely no longer Brahman (although it is possible that we were once conjoined in an aggregate of consciousnesses that may have somehow “designed” the world, implemented that design, and are now walking through our “art gallery”).   

 As we have seen, through replacement of atoms, the body we inhabit today is a totally different body from that of a decade age and the spheres of consciousness that inhabit it (including ourselves) are likely themselves different as well.  There is no Person in the sense of a continuing aggregation of matter or a continuing self.  The Person is likely to be, as Blackmore and Dennett insist, a story we tell ourselves.  However, it is a useful story, just like the story of my car or my kitchen table.  It helps credit card companies to obtain payments for purchases we made the preceding month and guides our interactions with former classmates at a high school reunion.  But in an absolute sense, the Person is only a cognitive construct, a very vivid hallucination.   We may be eternal (or least outlast the Energizer Bunny), but “we” (the People) have only a momentary time in the sun and may only be cognitive constructs, much like the ever-changing body of water that is now called the Mississippi River.

We cling to our present form of existence thinking that there is no other, but when you stop to think about the matter, human bodies, with their ills, needs and subjugation into mindless repetitive jobs, may not be the best places in the universe to inhabit.  In fact, they may be “mini-Hells,” aberrations in Great Cosmic Scheme.   But we may not inhabit such Hells (or such Heavens as there might be) for as long as we think.    The best thing for us to do is likely to take the poet Robert Frost’s advice and momentarily stop the “horses” we are currently riding to enjoy the beauty of the falling snow.  As Frost suggests, there may be miles to go (although perhaps not so many as one might think) before we sleep (and enter yet another dream).

The Game Plan

The remainder of this book further develops the themes outlined above (and defends the foregoing thesis regarding the relationship between conscious selves and the physical world).  In Chapter 1, we well will explore the nature of the relationship between mind (consciousness) and matter.  Chapter 2 continues this exploration with a consideration of the implications of quantum mechanics regarding the role of mind in the cosmos.  In Chapters 3 and 4, we will consider the evidence for psi phenomena, such as ESP and psychokinesis, in some detail.  The defense of the primary thesis regarding the role of conscious observers presented above will in no way rest on the existence of psi phenomena.  However, such phenomena, if they exist, have profound implications regarding the role of mind in the physical world (and they are entertaining and instructive to explore in their own right).  Chapter 5 is devoted to an exploration of the implications of psi phenomena, if they exist, for our views of reality in general and the nature of mind-matter interaction in particular.  Chapter 6 presents the existing evidence for the survival of the Person (including memories, emotions, and even physical appearance) of the death of the human body.  In Chapter 7, we will explore in further detail the nature of the self and the nature of mind-brain interaction.  In Chapter 8, we will turn again to a consideration to the role of mind in the physical universe, this time on the grandest of scales, by considering the anthropic principle and arguments that the universe may to designed to support the existence of (and possibly to entertain) conscious observers.  Chapter 9 contains a final summing-up of the evidence and conclusions presented in the main body of the book. 

It is time to get started.

1.  Mind and Matter

We begin with our journey with an examination of the relationship between conscious minds and physical matter (traditionally called the “mind-body problem”).

Historical Roots

Before launching into a discussion of modern views on the mind-body problem, it is helpful to consider the historical processes that gave rise to those views. In particular, an historical perspective will enable us to understand the almost religious vehemence with which some positions are held.

In the history of human thought up until surprisingly recent times, it was much more common to attribute mental or psychological properties to seemingly inanimate matter than it is today. Jonathan Shear, the founder and editor of the Journal of Consciousness Studies, notes that the problem of accounting for the existence of conscious experience that confronts modern science was not a problem for the ancient Greeks, as they viewed the material world as being imbued with mind, which served as a force governing the behavior of matter (Shear, 1995).  For instance, Thales of Miletus (died c. 546 B.C.E.) claimed that inanimate objects possessed a psyche allowing them the possibility of self-motion.  A century later Empedocles asserted that all elemental bodies were endowed with thought and sensation (Nash, 1995a).  Epicurus (341-271 B.C.E.) held that atoms have free will and could initiate collisions by swerving from their path, which was believed to be predetermined by such atomists as Democritus and Leucippus (Skrbina, 2005).  This idea has been revitalized many times over the course of development of Western thought.  Even as late as the turn of the last century, Ernst Haeckel (1899/1929) argued that in order for molecules to be attracted to one another, each must somehow “feel” each other’s presence.

 Aristotle taught that the natural state of any body was one of rest.  He asserted that the crystalline spheres which carried the planets and stars on their celestial voyages in his cosmology were associated with incorporeal “movers” that provided the force needed to maintain their motion.  He viewed these movers as being spiritual in nature and conceived of the relation of a mover to its sphere as “akin to that of a soul to its body” (Mason, 1962, p. 42).

Aristotle’s view was given a Christian interpretation by Christian philosophers such as Dionysius in the fifth century and Thomas Aquinas in the thirteenth century, with Aristotle’s “movers” being equated with the angels described in the Scriptures.  Aristotle also attributed psychological properties to baser matter, ascribing the tendency for a terrestrial object to fall to the Earth to its “aspiration” to reach its natural place.

Even as late as 1600, William Gilbert, an English physician and the founder of the scientific study of magnetic phenomena, proclaimed that the Earth has a magnetic soul analogous to the “magnetic soul” that Gilbert believed governed the behavior of lodestones. According to Gilbert, the rotation of the Earth and the inclination of its axis of rotation with respect to the sun were both caused by a desire on the part of the Earth’s soul to avoid extreme temperatures and to cause seasonal variations.  Almost two centuries later, in 1777, the English chemist Joseph Priestley asserted that physical matter was akin to “spiritual and immaterial beings” because of its properties of attraction and repulsion.

  These animistic views of matter gradually crumbled under the onslaught of scientific advances. The law of the conservation of angular momentum (earlier called the doctrine of “impetus”) led John Philoponos in the sixth century and William of Ockham in the fourteenth to deny the need to assume the existence of angels to keep the planetary spheres in motion. After all, if you spin a top, it keeps spinning by itself. (Philoponos was rewarded for this observation by being denounced as a heretic by the Church.)  

In rejecting Aquinas’ angels, William of Ockham was led to formulate his famous injunction “not to multiply entities beyond necessity,” which has since become known as “Ockham’s Razor.”  In fact, Ockham’s Razor, which was originally formulated to justify the exclusion of a class of spiritual beings (Aristotle’s angelic movers) is still one of the primary justifications used by modern scientists and philosophers to deny the existence of a realm of mental experience that is independent of physical events in the brain.  With regard to Ockham’s original application of his principle, the historian of science Herbert Butterfield (1957) viewed the impetus doctrine (in the form of the modern laws of conservation of momentum) as the primary factor underlying the banishment of a spiritual realm from scientific accounts of the world and the establishment in seventeenth century of the view of the universe as material clockwork-like mechanism.  The Calvinist John Preston proclaimed in 1628 that “God alters no law of Nature” (Mason, 1962, p. 181).  Divine intervention by deities or angels was no longer permitted; events were seen to be predictable from, and governed by, the laws of nature alone.   

 Vestiges of divine intervention persisted at least into the 18th century. Issac Newton asserted that divine intervention was necessary to reestablish the regular order of the planets’ orbits, which were constantly being deranged due to gravitational forces among the planets and comets and to a supposed gradual reduction in orbital velocity due to “ether drag” (Christianson, 1978).  However, in general the picture of the universe that emerged from the seventeenth century (at least in Western philosophy) was one of a huge impersonal machine governed by strictly mechanical principles.

Once the picture of the physical universe as a soulless machine gained ascendancy, not only did matter get stripped of its mental and spiritual aspects, so did living organisms. For instance, while Ernest Haeckel used an analogy between the growth of salt crystals and that of living cells to proclaim that all matter had a spiritual aspect, his contemporary Carl Nageli used precisely the same analogy to deny that biological cells were associated with a spiritual force, instead arguing that their growth was due to simple mechanical forces. The chemical synthesis of organic compounds in the laboratory, exemplified by Friederich Wöhler’s synthesis of urea in 1828, further undermined the vitalistic philosophies that insisted that a spiritual force governed biological processes.

Antoine Lavoisier had earlier demonstrated that the ratio of emitted heat to carbon dioxide was the same for candle flames as it was for animals, suggesting that respiration was a purely mechanical process.

While vitalism is not dead, its few modern advocates, including Arthur Koestler (1972, 1978) have been regarded as fringe thinkers by the scientific establishment.   

One of the contributors to this mechanistic cosmology was, paradoxically enough, the seventeenth century philosopher and mathematician Rene Descartes, who is widely regarded as being the prototype of the modern dualist (a dualist being one who regards the realms of mind and matter as having independent reality).  Among the phenomena that had most strongly indicated a mental aspect to matter were those suggestive of the operation of action-at-a-distance, such as gravitation and magnetism.  Descartes was able to eliminate this stumbling block on the road to a totally mechanistic outlook by proposing theories of magnetism (the vortex theory) and gravitation (the plenum theory) that avoided the problem of action-at-a-distance by assuming that these two types of force were transmitted through a physical medium.

Descartes extended his mechanistic philosophy to encompass living creatures as well as inanimate matter. He viewed animals as mere machines.  He did not, however, question the existence of minds in humans; indeed, he thought one’s primary and most direct knowledge was of one’s own mind. He viewed mind as a totally different kind of entity from matter. In Descartes’ view, one’s mind (or ego) was indivisible and hence lacked a basic character of matter—that of extension in space.  Thus, the mind inhabited a different plane of existence from the physical world and could not be said to have a spatial location.

Despite their different natures, Descartes proposed that the mind interacted with the physical body by deflecting the motion of the “animal spirits” flowing through the brain. He thought the pineal gland was the area of the brain in which this mind-matter interaction took place (as the pineal gland was the one structure that was not duplicated in the cerebral hemispheres and thus seemed appropriate to house a unitary and indivisible mind).  Because Descartes’ law of inertia held merely that the total quantity of motion in a system remains constant (but not necessarily its direction), he proposed that the soul acted upon the body by altering the direction of motion of the animal spirits, while not changing the intensity of that motion. 

The mathematician G. W. Leibniz, however, demonstrated that Descartes was in error and that directionality was conserved in the law of momentum.  Thus, Leibniz demonstrated that the physical body (as modeled by Descartes) was a deterministic system. There was therefore no room left for an influence of the mind on the body, and the mind was totally excluded from influence on the physical world. (It should be noted that mind retained a place in Leibniz’ own “monad” cosmology, although that cosmology never gained ascendancy in Western thought.)

As a deterministic clockwork physical universe allows no room for mind-action, it is not surprising that Cartesian dualism soon yielded to the materialism of Hobbes and La Mettrie (and more recently of Watson, Skinner, Dennett and the Churchlands). 

Once again, an application of the law of inertia led to the exclusion of the spiritual realm from scientific models of the world, only this time it was not angels being banished from the heavens, but the human soul itself being banished from its body. Indeed the historian of science Richard Westfall (1977) viewed the rigid exclusion of the psychic from physical nature as the “permanent legacy” of the seventeenth century.

However, since the emergence of the theory of quantum mechanics early in the last century, the brain is no longer viewed as a deterministic system. Thus, the argument from determinism no longer works, and there is now the possibility that an immaterial mind could interact with a physical brain by selecting which quantum state the brain enters out of the many states that are possible at any given time. 

The philosopher Michael Lockwood (1989) has noted that the prejudice in favor of matter was grounded in the apparent solidity of the former in the Newtonian worldview. Lockwood points out that the solidity of matter has disappeared in the theory of quantum mechanics (material particles exist as probability waves in an abstract mathematical space until they are observed) and that mind and matter are now both equally mysterious.

The tenacity with which some scientists resist the idea of an autonomous realm of mind is perhaps understandable in light of history. The emerging mechanistic picture of the world was fiercely resisted by the religious establishment, notable examples being the condemnation of Galileo for the crime of propounding the heliocentric (sun-centered) model of the solar system and the resistance to the theory of biological evolution that is still being mounted by Christian fundamentalists. Thus, any mention of an immaterial soul may raise fears of a descent back into religious irrationalism (and a consequent lack of funding) on the part of many scientists.

Edge (2002a) in fact attributes Descartes’ proposal of his theory of mind-matter interaction in part to his desire to remove the authority of the Church over the scientific investigation of matter.  Edge notes that science could only investigate matter with the tools available in the seventeenth century and that it was (and still is) “not equipped” to deal with mentalistic phenomena.   Edge (2002b) also attributes science’s embrace of the ancient Greek philosophy of atomism (in which the universe is conceived as being composed of microscopic, discrete elementary particles) as another move to reject, or circumvent, the authority of the Church.   

Let us now turn to an examination of modern views on, and “solutions” of, the mind-brain problem.

Monistic Philosophies

Monistic solutions to the mind-brain problem are those that postulate that the universe is composed of only one type of “stuff.” That “stuff” is usually taken to be mind, matter, or some sort of “tertium quid” having both mental and physical properties. Monism stands in contrast to dualism and pluralism, which comprise those philosophical positions that postulate the existence of two or more distinctly different types of “stuff,” with one of them typically being mind and another being matter.

Idealism. The monistic position that contends that the world is composed solely of minds and mental events goes by the name of idealism.  According to idealists, all that exists is mental experience. People consciously or unconsciously construct the hypothesis of a physical world in order to account for certain regularities in their sensory experience, but this is only a convenient fiction. The contention that the physical world may be an illusion is logically irrefutable.  For instance, you may think you are a human being holding a book on the mind-brain problem in your hand, whereas in fact you may be a nucleon-based life form on the surface of a neutron star who has gone into the analogue of a movie theater where strong pion fields have been applied to your brain both to induce amnesia for your real existence and to create in you the illusion that you are some two-legged elongated oxygen-breathing carbon-based being on a remote planetary body for the sole purposes of entertainment.  More simply, you could be merely dreaming or hallucinating. Following the Taoist philosopher Chuang Tzu, the reader might legitimately wonder whether she or he might be a butterfly temporarily dreaming about being a human being reading a sentence about butterfly dreams. I can remember arguing with someone against this position. I maintained that I could not be dreaming because of the clarity and consistency of my sensory experience. Imagine my surprise when I woke up. (This actually happened to me.)

All you can be certain of is your own existence. Seeking certain knowledge, Descartes found that he could not doubt his own existence as a thinking being.  In perhaps his most famous quote, he was led to exclaim, “I think, therefore I am.” All you can be absolutely certain of is your own existence and that you are now thinking certain thoughts, remembering certain memories, feeling certain feelings and sensing certain sensations. The inferences you make about your external environment based on these mental events may not be valid, as you may be hallucinating, remembering falsely, having groundless feelings and thinking delusional thoughts. The doctrine that only one’s self exists or can be proven to exist is a special case of idealism that goes by the name of solipsism.

  The various agencies presumed by idealists to be responsible for producing the illusion of the physical world have included God (in the view of the prototypical idealist, the eighteenth century philosopher Bishop George Berkeley, for whom Berkeley University was named), a collective mind or collective unconscious, and the illusion-producing state of craving and ignorance (according to certain schools of Buddhism).

The reply of most modern scientists and philosophers of science to idealism is that scientific theories that postulate the existence of an objective physical world have produced more exact predictions about possible human observations than have idealistic theories and therefore should be preferred over the latter for that reason. (Such theories are even covertly preferred by most solipsists, who seem strangely reluctant to step in front of illusory oncoming trains. Dr. Samuel Johnson said of idealism, “I refute it thus,” and then he proceeded to kick a rock with his foot. Johnson’s “refutation,” while actually proving nothing, did show his dedication to the anti-idealist cause.)

Idealism is not merely an historical curiosity, but even has its advocates today. Within parapsychology, for instance, Edgar Mitchell (1979), a former Apollo astronaut who once walked on the moon, suggested that an idealistic philosophy may have to be adopted in order to account for the evidence for psychokinesis (the alleged ability of mind to directly influence material objects and systems that are remote from the body.)  The physicist Amit Goswami (1993) has contended that an idealist conception of the world is required in order to render modern theories of physics, in particular quantum mechanics, coherent.

Radical Materialism. Radical materialism is the polar opposite of idealism. Radical materialists deny the existence of mental events, insisting that the world of physical matter is the only reality.  Incredibly enough, this philosophy held sway in the discipline of psychology itself in the early part of this century (at least in the United States).  Behaviorism emerged as the dominant force in psychology in this country as a reaction against the fallibility of the method of introspection that predominated in the earliest days of psychological investigation. Behavior was publicly observable and scientifically measurable, whereas the vague mental images that form, say, a particular individual’s idea of the number seven are not. Some of the leaders of the behaviorist movement, such as John Watson (1924/1970) and the earlier versions of B. F. Skinner (e.g., Skinner, 1953), went so far as to deny the existence of mental events altogether.  This denial of course flies in the face of the fact that the reader and I (if I am not a figment of the reader’s imagination) have directly experienced such mental events as sensations, thoughts, feelings and memories. Skinner’s position essentially contains its own refutation. Skinner could not consistently claim that he believed that mental events do not exist, as that belief would itself constitute a mental event. Therefore by his own theory (and reportedly by his own contention), Skinner’s expressions of belief in the doctrine of radical materialism were merely forms of physical behavior than he had been rewarded for displaying in the past (through royalties, academic honoraria, etc.).  If the books produced by Skinner are in fact merely the product of conditioned typewriter-pecking responses and the sentences within them do not express ideas, there is no need to take these books seriously.  It should be noted that Skinner did eventually retreat from this early radical version of his theory.

Materialism is not dead as a philosophy in modern cognitive neuroscience, however. The philosopher Paul Churchland has recently proposed doing away with “folk psychology” (talk of mental events such as beliefs and desires) in all human discourse (Churchland, 1989, 1995).  He would replace “folk psychology” with a strictly neural account of behavior. Thus, instead of a wife telling her husband that she is really angry at him, she would say instead, “The neurons in my amygdala seem to be firing at an unacceptably high rate.”   

Churchland has in fact gone so far as to assert that truth might cease to be an aim of science! This assertion is implicitly based on the assumption that the concept of truth presupposes the existence of propositions capable of being true or false, which in turn presupposes the existence of mental events such as thoughts, ideas and beliefs that are expressed in such propositions. Churchland proposes that scientific theories should no longer be expressed in terms of sentences but rather in terms of patterns of connections among neurons (or among the pseudoneurons in a computerized “neural net,” as discussed below). But now we are right back where we started. Unless human knowledge is to be given up entirely, Churchland must at least be able to entertain propositions such as “neural net A diagnoses diseases more accurately than does neural net B.” Such propositions, however express beliefs. If Churchland seriously wishes to give up the “folk psychological” concept of belief, then his philosophy self-destructs in the same way that Skinner’s did.

Skinner, incidentally, was by no means the last modern thinker to deny the very existence of private conscious experience, or “qualia” in the terminology of philosophers. The prominent materialist philosopher Daniel Dennett has asserted that “contrary to what seems obvious at first blush, there simply are no qualia at all” (Dennett, 1988, p. 74).  This statement may go a long way toward explaining Dennett’s reasoning.  However, I imagine that reader (like me) has personally experienced a great number of qualia, such as brilliant patches of red and pangs of hunger.  Qualia may be both beautiful and horrifying.  Dennett doesn’t know what he is missing.

Quasi-dualistic materialism. More sensible versions of materialism concede the existence of mental events, but contend that mental events arise solely from physical events and that a complete scientific description of the world can be given in terms of physical processes alone. In one version of this theory, mental events are thought to be brain events experienced from the “inside.” This view goes by the names “central state materialism” and “neural identity” theory, among others. A related doctrine is double-aspect theory. Double-aspect theorists contend that mental and physical events are merely two aspects of a single underlying reality. As the vast majority of double-aspect theorists implicitly or explicitly assume that this single underlying reality is essentially physical matter, this theory is basically equivalent to the previous two. 

Panpsychism.  A similar doctrine is panpsychism, which asserts that all matter, not just living organisms, has a mental aspect.  This view has been advocated by the prominent Western philosopher Alfred North Whitehead (1929/1978), among others.  

Panpsychism, with its contention that rocks and toothbrushes enjoy some form of consciousness, strikes one as absurd at first brush (or even more clearly upon a secondary cursory inspection of one’s toothbrush).  However, when you carefully consider it, the doctrine begins to grow on you.  

A prominent recent proponent of this position is the philosopher David Ray Griffin (1988a, 1988b, 1994, 1997), although he prefers to call his doctrine “panexperientialism” rather than “panpsychism,” as he does not contend that rocks and other inanimate collections of material particles possess a highly unified and structured consciousness, but rather ascribes only vague “feeling-responses” to them.  More highly complex and structured forms of consciousness, in Griffin’s view are restricted to “compound individuals.”  Such compound individuals are composed of, or arise from, a hierarchical collection of more primitive selves or “individuals.”  For instance, a neuron would be a compound individual in relation to its individual constituents such as molecules, and a “suborgan” such as the hippocampus of the brain that is composed of neurons would be a compound individual somewhat further up the hierarchy.  All such “individuals” would have both mental and physical aspects under the panexperientialist view, although only hierarchically-ordered structures would be assumed to have a highly organized and structured consciousness.  Less well-organized structures, such as rocks, would be ascribed only vague “feeling responses” according to Griffin’s panexperientialist theory.   

David Skrbina (2003, 2005) has recently provided a comprehensive and brilliant defense of the doctrine of “panpsychism.”  Skrbina argues for instance that an electron must somehow sense the presence of a proton in order to respond to its attractive force.  (An electron may even enjoy a certain degree of freedom of action due to quantum indeterminacy and may be able to sense a quantum field that is highly complex and global in nature.)  

As does Griffin, Skrbina associates more complex forms of consciousness with aggregates of matter, such as single neurons, or large assemblies of neurons such as hippocampi and cerebral hemispheres.  (However, it should be noted that, as discussed in the previous chapter, such aggregates of matter, much like one’s personality and physical body, do not persist over time and thus cannot form the basis of a continuing self.  Also, fields of consciousness appear to be unitary and indivisible, much more like a quark than like a molecule or a neuron.)

 As Skrbina points out, the panpsychist position solves the problem of “emergence” or the need to account for how organisms acquired consciousness in the course of evolution (i.e., how insensate matter gave rise to consciousness).  As he notes, there is no definitive line of demarcation that can be drawn between conscious and nonconscious organisms, in either the present world or in the course of evolution.  If all matter is imbued with consciousness or if fields of consciousness are fundamental constituents of the universe that have existed throughout its history, then the problem of evolution of consciousness (and of how a three-pound “hunk of meat” like the human brain could generate conscious experiences in the first place) does not arise.

It should, however, be noted that panpsychism still faces the difficulty of accounting for the emergence of a unified mind and global consciousness out of a myriad of psychic elements, as was pointed out long ago by William James and, more recently, by William Seager (1995).

Epiphenomenalism.  Epiphenomenalism is technically a form of dualism, insofar as it grants separate reality to the realms of mind and matter; however, I will classify epiphenomenalism as a form of quasi-dualistic materialism, as it denies that mental events have any influence whatsoever on the physical world. Mental events are considered to be mere “epiphenomena” of physical events in the sense that, while mental events are caused by physical events, they are themselves incapable of causing or influencing physical events. A prominent advocate of epiphenomenalism was the biologist Thomas Henry Huxley (1874, 1877), the grandfather of the noted writer Aldous Huxley,  who was perhaps most noted for his tireless defenses of Darwin’s theory of evolution (so much so that he earned the nickname “Darwin’s Bulldog”).

  Several writers, including the noted mathematician Roger Penrose (1987b) and Karl Popper and John Eccles (1977) have noted that epiphenomenalism in fact goes counter to Darwinism. Why should a conscious mind have evolved, they ask, if it did not play an active role in benefiting the organism? 

Also, and perhaps most amusingly, the mere existence of epiphenomenalist theories is in itself sufficient to refute the doctrine of epiphenomenalism.  After all, epiphenomenalism was developed as an attempt to explicate the role of mental events; therefore, the theory has been created in response to (i.e., has been caused by) mental events; otherwise, epiphenomenalism could not claim to be a theory of mental experience.  Thus, the theory of epiphenomenalism is refuted by the fact of its own existence.  

The physicist Heinz Pagels (1988) raised the question of whether the universe could be a giant computer, much as a personal computer screen can become transformed into a mini-universe with quasi-organisms evolving on it when a program realizing mathematician John Conway’s “game of life” is run on it.  This idea had previously been suggested by Ed Fredkin of M.I.T. and explicitly endorsed by Tomasso Toffoli (1982).  This view has been most recently revived by the noted mathematician Stephen Wolfram (2002), who suggests that universe is best understood as a giant cellular automaton (computerized grid of cells following prescribed rules of behavior).  If this suggestion that the universe is in fact the product of a giant computer has any validity, we cannot equate ourselves with the godlike programmers who created the universe and assume that we have simply each become entranced in the life of one of our three-dimensional creations (which we have come to regard as our physical body). Because of the arguments against epiphenomenalism, we cannot be mere spectators in the world. Our consciousnesses have a more active role in the universe than that.   

Physicalism.  The philosophical positions that I have grouped together under the heading of quasi-dualistic materialism would seem to be equivalent to one another as scientific theories, insofar as they all apparently make the same scientific predictions (mainly that no violations of the known laws of physics will occur in the brain and that no successful predictions regarding the behavior of the brain can be generated from theories involving nonphysical entities such as souls or minds that could not in principle at least be derived from theories referring solely to physical entities and processes).

The empirical findings that most directly challenge the doctrine of physicalism derive from the parapsychologists’ investigations of ostensible psi phenomena such as the clairvoyant reading of ESP cards and psychokinetic influence of the fall of rolling dice.  Because of their importance in this debate and because of the controversies surrounding parapsychological research, these findings and their implications will be discussed in some detail in Chapters 3 through 5.  However, as we have seen in Chapter 0, this evidence is not needed in order to build a strong case that one’s individual self or consciousness is something other than one’s physical body and may be capable of surviving the death of that body, or (perhaps more likely) of departing the body and becoming associated with a new physical system well prior to the death of the body.   

It is commonly held, both by parapsychologists and skeptics, that psi phenomena are inexplicable on the basis of current physical theories and are thus evidence against the doctrine of physicalism, if the latter is construed as the contention that all phenomena can be ultimately accounted for in terms of present theories of physics or relatively minor extensions thereof.

 Joseph Banks Rhine (the researcher who is largely regarded as the progenitor of modern parapsychology and who established the first major research program in experimental parapsychology at Duke University in the 1930s) in particular was highly skeptical that psi phenomena could be explained on the basis of any physicalistic theory. In fact, Rhine suggested that psi was nonphysical in nature, due to the lack of dependence of experimental psi-scoring rates on spatial or temporal separations and the lack of attenuation of the psi signal by physical barriers between the percipient and the target object (e.g., ESP card or die) that would block most known forms of physical signals (such as electromagnetic radiation).  Rhine also cited the fact psi success appears to be independent of the physical nature of the target object, as well as the apparent backward causation in time involved in precognition (and, we might now add, retroactive psychokinesis), as further evidence against any physicalistic explanation of psi phenomena.  At one point, Rhine (1972) postulated the existence of “nonphysical energy” in order to explain psi, a concept that the noted dualist philosopher John Beloff considered to be oxymoronic (Beloff, 1981).

Michael Levin (2000) has made the argument that if psi abilities are based on physical processes grounded in the biomechanical properties of the body, then surely these abilities would be selected for in the process of evolution and would by now be readily apparent in animals’ behavior.  The fact psi is an elusive and rarely observed ability, Levin asserts, constitutes further evidence that it is not derived from the biomechanical workings of animals’ bodies. 

Because it appears to be difficult to account for psi phenomena on the basis of known physical theories or principles, it is often believed that the existence of psi phenomena would falsify physicalism (where “physicalism” denotes the class of theories encompassing radical materialism and quasi-dualistic materialism). As the vast majority of working scientists subscribe to some form of physicalistic solution to the mind-body problem, it should not be surprising that they would choose to reject the claims of parapsychology, insofar as those claims tend to threaten their worldview. 

Some of the resistance of establishment science toward accepting the existence of psi may stem back to the fact that Western science has relatively recently (in the vast scheme of things) emerged from a battle with the Church over who would hold the authority regarding determining the nature of reality, the trial of Galileo being only one prominent example.  There are those who believe that some sort of truce should be declared between science and religion, such as Stephen J. Gould, who asserted that science and religion should be considered as “separate magisteria,” with science holding reign over matters of empirical fact and religion holding reign over ethics and matters of the spirit (Gould, 1999).   However, despite Gould’s contentions, science and religion are in many cases still in conflict over empirical questions, as is evident in the ongoing battle of religious creationists in the United States to have Dawrwin’s theory of evolution either removed or downplayed in high school biology curricula.

This conflict continues to underlie much of the scientific establishment’s resistance toward accepting the findings of parapsychological investigations.    For instance, in a scathing attack on parapsychology, Nicholas Humphrey (1996) asserts that the questions of the existence of souls and of the existence of paranormal powers are not independent issues and that the possession of a soul would imply the existence of such powers. On the other side of the fence, as psi phenomena suggest the existence of a nonphysical aspect to the mind, many people who would prefer to believe in the existence of an immortal soul may tend to adopt a belief in psi phenomena in support of their position. Indeed, John Beloff (1983) even asserted, in a Presidential Address to the Parapsychological Association, that the existence of an afterlife is contingent on the existence of psi, in seeming agreement with Humphrey’s position.  This is undoubtedly too strong an assertion, however, as it is quite conceivable that a mind or soul (or more likely a field of pure consciousness) could survive death even if the living person (or surviving trace) did not possess the powers of ESP and PK.

Even if it is assumed that the explanation of psi phenomena will require the postulation of entities and principles beyond those currently known to physicalistic science, it may be a mere issue of terminology whether such entities are to be considered material or nonmaterial.  If the former, the physicalist can claim victory; if the latter, the dualist can claim the same. Obviously, if mind and matter interact, they form one united system.  Whether one chooses to call that system the physical universe may be a matter of semantics rather than substance. (Some of the theoretical concepts already employed by physicists, such as the quantum-mechanical wave function discussed in the next chapter, already seem more mind-like than material in any event.)

Strangely enough, J. B. Rhine himself disavowed any position of dualism. John Beloff (1981) traces Rhine’s eschewal of dualism to his difficulty in seeing how such dissimilar things as mind and matter could interact, although Beloff himself sees no reason why a cause must necessarily be of the same nature as its effect.   Beloff suggests that Rhine’s position may have been motivated by a desire to avoid charges of supernaturalism as well as a desire to leave the door open for an ultimate cosmology that would embrace both mind and matter.  Beloff notes that Rhine recognized that psi might potentially be given an explanation in terms of quantum mechanics and that Rhine only wished to state the incompatibility of psi with “conventional” physics. Interestingly enough, Frederick Dommeyer (1982) has classified Rhine as a double-aspect theorist, presumably referring to a version of double-aspect theory in which the common substance underlying mental and physical events is something other than matter as currently understood.  

Several other parapsychological theorists have proposed versions of the double-aspect theory. Edmund Gurney, one of the early pioneers of psychical research, proposed that some third form of existence or “tertium quid,” in addition to mind and matter, would be required in order to explain mental phenomena and to bridge the gap between mind and brain (Gurney, 1887).  In more recent times, Carroll Nash (1976, 1995b) has proposed a double-aspect theory to explain psi phenomena.  Nash proposes that mind and matter are each aspects of some tertium quid, or neutral substance, that is not governed by space, time or causality, thus allowing psi to occur (as well as providing the basis for mystical experiences). Nash’s theory does not, however, appear to be sufficiently developed to enable testable predictions to be derived from it.  

Susan Blackmore (2001) has noted that psi phenomena are frequently invoked in support of the contention that consciousness plays some fundamental role in the universe.  She argues that, in view of the fact that psi is often considered to operate primarily at a subconscious or unconscious level, the assertion that psi phenomena are evidence for a fundamental role for consciousness is unwarranted.

Machine Consciousness. Most people would grant consciousness to seemingly intelligent animals such as chimpanzees, elephants, whales and dogs, although there are still those who follow Descartes’ lead in denying consciousness to all animals other than human.  (Descartes thought that “lower” animals were mere machines, from whence springs the opinion expressed by some people today that animals can not suffer or feel pain, thus rationalizing the mistreatment of such animals.)  Most people, aside from the panpsychists, would draw the line between conscious and nonconscious beings somewhere “down” the “hierarchy” of living and nonliving things, perhaps before one gets to ameobae, petunias, or slabs of granite.  

What about humanly-manufactured machines that exhibit more complexity and activity than does, say, a slab of granite?  Do thermostats feel a twinge of pain when the thermometer passes the set point and the furnace is not yet turned on? The famous neurophysiologist W. Grey Walter constructed mechanical “tortoises,” which ambulated about his house randomly until they ran low on power, at which point they would proceed to the nearest electrical socket to recharge themselves. Were Walter’s tortoises conscious?  Did they feel “hunger” for electricity?  What about modern computers that can defeat any human at chess?

Many people argue that, if a machine or computer were able to duplicate human thought processes, there is no need to postulate the existence of an immaterial mind or soul to explain human thought, as human-manufactured computers are presumably not endowed with such ethereal entities as souls or minds.

Roger Penrose (1987b), David Layzer (1990) and John Searle (1990), have argued that, even if computers were to prove capable of simulating human behavior, this would not imply that computers possess awareness or have conscious experiences. Rather, they see the biochemical “wetware” of the human brain as having specific properties necessary for the production of consciousness that the hardware of a typical digital computer lacks.  On the other hand, their assertions that the particular properties of biological wetware are necessary for the generation of conscious experience are not in general supported by any convincing argument.  It would be desirable, therefore, to have a more or less objective test to determine whether a computer or robot is conscious.

Just such a test was proposed by the mathematician Alan Turing (1950, 1964) in the form of an imitation game (which has since become known as the Turing test).  If a human being communicating with a computer and with another human being through a teletype machine (or, these days, a computer monitor) cannot tell which is the computer and which is the human being, then the computer should be deemed conscious (in other words, if you are willing to ascribe consciousness to the human being on the basis of her behavior, you should extend the same courtesy to the computer).

Could a computer successfully pass the Turing test? Computers operate by following mathematical algorithms (fixed, mechanical procedures for solving a problem or producing output).  Roger Penrose (1987b, 1989, 1994) has argued that human thought does not rely exclusively on such algorithms. Penrose bases his contention that human thought must have a nonalgorithmic component in part on mathematician Kurt Gödel’s famous incompleteness theorem. In 1931, Gödel shocked the mathematical world by demonstrating that there exist statements within any reasonably powerful mathematical axiom system that are true but which can never be proved to be true within the axiom system itself. To oversimplify slightly, such a statement might read as follows: “This theorem is not provable.” Let us call this statement Theorem X. If Theorem X were provable, a contradiction would result, as Theorem X asserts its own unprovability. Therefore, if the mathematical axiom system is consistent, Theorem X could never be proven. Consequently, Theorem X is true, as it simply asserts its own unprovability. Computers, being driven by algorithms, are equivalent to mathematical axiom systems. Hence, a computer would be unable to perceive the truth of its own Theorem X, as it would only regard as true those statements that it could prove.  Humans, on the other hand, are readily able to perceive the truth of such statements as Theorem X.  Hence, Penrose argues, human thought is not algorithmic and therefore could not be simulated by an algorithmic computer. The chief difference between the computer and the human in this regard might be that the human can understand the meaning of the statements involved, whereas computers just blindly manipulate symbols according to prescribed rules without any idea of what those symbols might mean.

Penrose has further argued that, as human awareness must be noncomputational in nature and as current laws of physics are essentially computational systems, new principles of physics may be required to explain humans’ capacity to achieve direct insight into mathematical problems and to understand the meaning of language. 

Penrose (1994) observes that Kurt Gödel himself maintained that the mind was not identical to the physical brain, as Gödel felt that the physical brain would necessarily be a computationally-based system.  Gödel was thus a dualist.  As we shall see, Penrose has come to view consciousness as intimately connected to nonlocal quantum processes in the brain.  He sees such noncomputable quantum processes as being a prerequisite for consciousness.  Any system based entirely on simple computation must be nonconscious in Penrose’s view.

Paul Churchland (1995), perhaps the foremost defender of radical materialism in the modern era, has expressed agreement with Penrose’s position that human reasoning is nonalgorithmic.  Churchland does not, however, see such nonalgorithmic reasoning as emerging from arcane quantum mechanical processes, but rather from the continuous, analog nature of the human brain (as compared to Turing machines, which operate by entering one discrete state after another).

Philosopher John Searle (1987, 1990) has argued that even if a computer were to successfully simulate human behavior, this would not imply consciousness on the part of the computer. As an analogy, he considers the case of a person who does not speak Chinese who sits alone in a room with a book of rules instructing him how to respond to strings of Chinese characters. While a speaker of Chinese may think he is engaging in a dialogue with this person by swapping notes back and forth under the door to the room, the person inside the room does not in fact understand what the Chinese speaker is saying or what he himself is saying, as he does not know what the symbols mean. Similarly, Searle argues, computers are engaged in a purely syntactic manipulation of symbols and have no idea of what those symbols mean. 

Christian Kaernbach (2005) recently tested Searle’s Chinese room argument by having human subjects simulate addition and multiplication modulo 5 (i.e., “clock” arithmetic on a five-hour clock in which 3 + 4 = 2, for instance) by following a “look up” table similar to that provided to the subject in Searle’s Chinese room.  Kaernbach found that his subjects gained no insight into the meaning of their symbolic operation unless they were specifically informed of the connection to mathematical operations.  Kaernbach’s results would appear to substantiate Searle’s intuition.

In his later publications, Searle does concede that a robot might be said to have semantic and not just merely syntactical understanding of linguistic symbols if the robot were provided with sensing devices (such as TV cameras) and motor apparatus (such as robot arms). In such a case, the robot could develop a sensory “awareness” of the outside world and could gain an inkling of “insight” into the fact that words refer to objects and events in an outside world.

 It may be argued that, even if a computer could simulate human thought, humans quite possibly possess psi abilities that may be indicative of a spiritual or immaterial aspect to human beings.  Computers, being mere machines, would presumably be incapable of demonstrating such psi powers. Actually, Turing himself considered this objection in his original proposal of the imitation game. He suggested that computers might be able to manifest, or least simulate, psi powers if a random event generator (REG) were included in the computer’s design.  Such REGs, which are a common tool of the parapsychologist’s trade, are essentially electronic “coin flipping” devices, often based on quantum mechanical uncertainty.  For instance, “heads” might be defined to occur if a Geiger counter recorded the first decay of a strontium 90 atom in as occurring during an odd microsecond, and “tails” might be defined to occur if the first decay occurred during an even microsecond. Such quantum mechanical decay is based on the Heisenberg uncertainty principle and is (according to standard theories of physics) truly random.  Even a physicist with complete knowledge of the REG system (which must be less than complete in any event due to the Heisenberg uncertainty principle) could not predict when such a decay will occur.

Once the REG system is implanted in the computer, the computer might appear to have psi powers (at least if humans themselves have such powers).  For instance, in a telepathy experiment, the “sender” (e.g., person looking at an ESP card and attempting to transmit its identity to the computer) could subconsciously use his psychokinetic (PK) powers to influence the REG in such a way as to make it appear that the computer has ESP.  Various PK tasks posed to the computer might be performed inadvertently through the experimenter’s use of her own PK abilities (especially if the experimenter was rooting for the computer).  Thus, to all appearances, the computer would have psi powers. 

To pursue this line of thought even further, it would be interesting to speculate what would happen if a large number of quantum-mechanically based REGs were installed in the computer.  If minds are to be equated with the “hidden variables” that govern the outcome of quantum decisions, perhaps such a largely nondeterministic computer would be able to acquire a mind.  Of course, it would no longer be the sort of deterministic, algorithm-following sort of computer that is known as a Turing machine. Instead, it might be something approaching a silicon-based life form.

In the end, the real test of consciousness in automata such as robots and computers may be to wait to see if such machines spontaneously express curiosity and wonderment about their own inner experience, much as human philosophers of mind do. Presumably, a nonconscious computer would not develop a preoccupation with the machine equivalent of the mind-body problem.

Dualistic Philosophies

We are thus led to consider dualist positions, which grant independent reality to both mental and physical events. We will begin with parallelism.

Parallelism. Parallelism is a peculiar form of dualism in that it insists that the realms of mind and matter are totally separate and do not interact at all. One of the foremost advocates of this doctrine was the seventeenth century mathematician and philosopher Gottfried Willhelm Leibniz (1714/1965), who asserted that God had placed the physical and mental realms in “preestablished harmony” so that they are forever in correspondence with one another, much as two synchronized clocks continue to display the same time as one another. Parallelism seems to have one more realm than it needs.  After all, the reason that we postulate the existence of a physical world in the first place is to explain certain regularities in our sensory experience. If the physical world is not the cause of our sensations, there is really no reason to postulate its existence at all. Which brings up…

Interactionism. Interactionists, as their name implies, assume that the mental and physical realms do in fact interact with one another. Unlike epiphenomenalism, in interactionism the causal highway is a two-way street. Not only do events in the physical realm cause mental events, but mental events are capable of influencing physical events as well.  As we have mentioned, since the advent of the theory of quantum mechanics, the brain is no longer considered to be a completely deterministic system and therefore could be open to influence from a mental realm. (In this context, however, it should be noted that some die-hard materialists such as philosopher Daniel Dennett (1991) continue to reject dualism on the basis of arguments involving the outmoded concept of a deterministic brain system.)  In fact, the brain seems almost designed in such a way as to maximize its receptivity to such influence from a nonmaterial mind. Neurophysiologist John Eccles has called the brain just “the sort of a machine a ‘ghost’ could operate,” as its functioning is dependent on minute electrical potentials and the motions of neurotransmitter molecules and calcium ions (Eccles 1953, p. 285).  Several prominent physicists, including Niels Bohr (1958), Arthur Eddington (1935), Henry Margenau (1984), Euan Squires (1990) and Henry Stapp (1992), have explicitly proposed that the mind interacts with the brain by influencing the outcome of quantum processes within the brain.  

Roger Penrose (1987a) has suggested that the “oneness” or “global” quality of consciousness may be related to nonlocal quantum connections between neural processes in the brain, and he further notes that neurons, unlike the elements of deterministic computers, are subject to quantum mechanical influences.  In the more recent versions of Penrose’s theory, he proposes that water molecules in the microtubules composing the cytoskeletons of widely separated neurons could exist in a quantum-mechanically coherent state. As the configuration of such cytoskeletons could influence the synaptic connections between neurons, this would provide a nonlocal means of unifying neural activity over wide regions of the brain. In fact, Penrose equates the operation of free will with quantum mechanical decisions influencing the configuration of such microtubules.  It should, however, be noted that Penrose objects to the dualistic view that an immaterial mind external to the physical brain system can influence the outcomes of quantum mechanical processes in the brain.  Rather than being caused by conscious awareness, Penrose proposes that quantum mechanical state vector reduction occurs when the energy difference between the alternative physical outcomes becomes sufficiently great (Penrose, 1994).  Penrose’s theory is based in part on Stuart Hameroff’s proposal that the cytoskeletal microtubules within neurons may be centrally involved in the computational activity of the brain. Hameroff, incidentally, concurs with Penrose’s view that conscious experience may involve nonlocal quantum connections between microtubules in widely separated neurons.  Hameroff thinks that such connections may help to bind diverse neural activity into unified perceptions and experiences and to provide a unified sense of the self. He also sees such connections as providing the indeterminism necessary for the operation of “free will” (Hameroff, 1994).   

In particular, Penrose has contended that water molecules in widely separated microtubules could exist in a quantum-mechanically coherent state and that nonlocally correlated changes in cytoskeleton configurations could alter synaptic connections between neurons. He sees such conformational changes as being intimately associated with the experience of “free will” (Penrose, 1994).  However, Rick Grush and Patricia Churchland (1995) have argued that microtubules are not in close enough proximity to the synaptic complex to influence synaptic transmission.  They also note that the gout drug colchicine depolymerizes microtubules, disrupting any quantum mechanical coherence that might be present, but is not associated with any loss of consciousness.   In reply to Grush and Churchland, Penrose and Hameroff (1995) counter that very little colchicine enters the brain and that most brain microtubules are hardened and do not undergo cycles of polymerization and depolymerization. They also note that the drug does in fact cause impairments in learning and memory.

  David Hodgson (1991) has seconded Penrose’s assertion that consciousness is intimately dependent on nonlocal connections between spatially separated brain events.  In his view, such connections help forge a united perception of an object from its separate features.  He conjectures that nature had to provide such nonlocal connections in order for consciousness to exist.  He further contends that only indeterministic systems are associated with consciousness, as conscious minds would be of no use to a mechanistic system.  Physicist A. J. Leggett  (1987a) has even suggested that new quantum principles may be needed to describe the behavior of complex systems such as brains.  Penrose (1994) agrees with this position of Leggett and proposes that new laws of physics will be required to explain noncomputational brain activity.

There has even been an attempt to subject the theory that nonlocal quantum processes undergird conscious thought to an experimental test.  Nunn, Clarke, and Blott (1994) found that when a record was made of the electrical activity of one of the brain’s hemispheres, performance on psychological tasks involving that hemisphere was enhanced.  More specifically, they found that subjects’ performance in a button-pushing task was more accurate if EEG recordings were made of the motor areas of the brain involved in the task than if recordings of other areas of the brain were made.  Presumably, the making of an EEG recording assisted in collapsing quantum mechanical state vectors, resulting in more efficient cognitive performance.  

There have been many who have had difficulty conceptualizing how such different entities as mind (which Descartes and many subsequent philosophers regarded as immaterial and lacking any spatial extension) could interact with matter.  For instance, in regard to Descartes’ notion that the mind interacted with the human brain through the deflection of the animal spirits as they passed through the pineal gland, the philosopher Thomas Metzinger says: 

Something without any spatial properties cannot causally interact with something possessing spatial properties at a specific location.  If Descartes had taken his own premises seriously, he could never have come up with this solution, which is so obviously false.  If the mind truly is an entity not present in physical space, it would be absurd to look for a locus of interaction in the human brain.  (Metzinger, 2003, p. 381.  Emphasis in original.) 


As each of us seems to be somehow “stuck” in a human brain, however temporarily, it would in fact seem that the self, construed as a field of consciousness, does have some spatial properties, if only the property that it is, at least temporarily, somehow stuck to (or under the panpsychistic hypothesis, part of) a human brain occupying a particular region in space.

From this it does not follow that the self in its entirety is confined to a spatial location in the human brain or circumscribed region of space.  As we shall see in the next chapter, even the elementary particles of matter such as electrons and protons typically do not have any particular spacetime location until they are forced to adopt one through an act of observation.  Even physical matter lacks the material properties ascribed to it by Metzinger.

The British psychologist and philosopher John Beloff (1998) notes that under the general theory of relativity, matter influences and is influenced by spacetime, despite the fact that material particles and spacetime continua are radically different types of entities.  If their different natures do not prevent matter and spacetime from mutually influencing each other, argues Beloff, then there is not reason why mind and matter could not also interact despite their seemingly different natures.  Similarity in properties may not be a necessary condition for causal interaction.

Another conceptual objection to interactionism is that mind-brain interaction would involve violations of the laws of physics.  Many writers, including Mohrhoff (1999), Wilson (1999), Levin (2000), Jaswal (2005) and Clark (2005a), have argued that any action of a nonphysical mind on the brain would entail the violation of physical laws, such as the conservation of energy and momentum and the requirement that the outcomes of quantum processes be randomly determined.

Levin (2000) argues that dualist interaction would involve a violation of the law of the conservation of energy.  However, the noted philosopher Karl Popper has suggested that the mind may have its own source of (presumably physical) energy.  Under this view, the mind would be a sort of quasiphysical object that might be capable of greater influence on the brain than that allowed by the Heisenberg uncertainty principle of quantum mechanics. Popper even went so far as to assert that the law of energy is only “statistically valid” (Popper & Eccles, 1977, p.541).  Without going to this extreme, it could be argued that mind is capable of exerting some force on some of the material particles in the brain.  Also, we are a long way from having measured with precision every minute energy transaction in human brains. In the process of doing so, it is conceivable that some unexpected energy transaction may be observed. If science should progress to the point where the action of spheres of consciousness on energy transactions within the brain can somehow be mathematically (or otherwise) described, this might be a victory for the contention that immaterial minds can exert physical force.  If such spheres of consciousness are identified with known material particles and system, the physicalists could claim victory.  If not, the dualists could so declare.  

If spheres of consciousness could exert some sort of physical force, it is likely that they would be declared as a new form of physical matter or energy, resulting in a victory for the physicalists.  If the present day physicalists opine that all physical particles have already been discovered, this may only be evidence for the psychological tendency toward premature closure, in that they fervently wish to believe that they already possess virtually complete understanding of the universe.  But such a declaration could only be the worst form of arrogance in view of the fact, already noted, that physicists have only recently discovered the existence of dark energy, which is now believed to comprise three-quarters of the matter-energy in the universe.

Many writers (e.g., Beck, 1994; Bohr, 1958; Eddington, 1935; Hameroff, 1994; Hodgson, 1991, 2005a; Leggett, 1987a, 1987b; Margenau, 1984; Penrose, 1994; Squires, 1990; Stapp, 1992, 1996; Walker, 2000) have noted that the classical deterministic theory of Newtonian physics has been replaced with the indeterminism of quantum mechanics, in which many possible futures may arise from a given present state of the universe, and have suggested that the conscious mind or “free will” may act on the brain by selecting a particular quantum state (i.e. forcing the quantum mechanical state vector to “collapse” to a desired outcome).  In fact, Eccles (1953, p. 285) noted that the brain is just “the sort of machine a ‘ghost’ could operate,” as its functioning is dependent on minute electrical potentials and the motions of neurotransmitters and calcium ions.  Thus, in Eccles’ view, at least as expressed in his later writings (e.g., Eccles, 1989), changes in macroscopic brain activity may be brought about without violating the limits of indeterminacy allowed under the theory of quantum mechanics.

A similar view has been expressed more recently by physicist Henry Stapp (2005b), who asserts that quantum mechanical laws must be used to describe the process of exocytosis (the emission of neurotransmitters into the synaptic cleft), citing empirical research in support of this assertion (Schwartz, Stapp & Beauregard, 2005).  In particular, Stapp notes that the “quantum Zeno effect” (maintaining a quantum state through repeated observation) provides a means whereby conscious minds could act on the physical brain, namely by holding the brain in a particular state.  He cites William James’ observation that the role of conscious attention is to preserve brain states in support of this view.  He also notes that Pashler (1998) has observed that consciousness may act as an information-processing bottleneck in this regard.   

Contrary views have been expressed by Jaswal (2005) and Clark (2005a), among others, who argue that any such influence on quantum mechanical processes would lead to a violation of the statistical predictions of quantum mechanics and the principle that the outcome of quantum mechanical processes are randomly determined.  Such influence would therefore constitute a violation of the laws of physics.   

First of all, it should be noted, as many observers have argued, that description of the universe afforded by the laws of quantum mechanics is incomplete.  Also, no one has provided, or likely ever will provide, a complete description of the quantum state of any brain at any time.  We may discover new entities or processes that may be identified with the so-called “hidden variables” that determine the outcomes of quantum processes.  Also, quantum mechanical outcomes may indeed be random in simple physical systems, but may be less random in certain complex systems, such as human brains, in which the observing consciousnesses may have a more vested interest.  It may also be that such consciousnesses enjoy a closer physical proximity to physical brains, on the view that quasi-physical spheres of consciousness may be, at least, temporarily, somehow “stuck” in physical brains.  

Thus, it might turn out that the outcomes of quantum processes inside complex systems such as brains are not randomly determined but are governed by fields of consciousness, whereas those in simpler systems are not so governed.  Also, many parapsychological researchers, going back to Schmidt (1969, 1970), have produced evidence that conscious minds may be capable of determining, or at least biasing, the outcomes of quantum processes, as will be discussed in more detail in subsequent chapters.  

Having discussed the general framework, we will now consider specific versions of dualistic interaction that have been proposed in recent times.  Thus discussion will be an introductory one, and a more detailed discussion of some of the philosophical and scientific issues raised by modern models of dualistic interaction will be postponed until Chapters 2, 5 and 7.

Eccles’ theory of mind-brain interaction.  There are few adherents to the doctrine of dualistic interaction among working scientists today.  John Eccles was perhaps the most prominent example of such a scientist in the second half of the twentieth century.  Eccles was a renowned neurophysiologist, who in 1963 shared the Nobel prize in medicine and physiology with his coworkers A. L. Hodgkin and A. F. Huxley.  The prize was awarded for their studies of the axons of the giant squid, establishing the membrane theory of nerve conduction and demonstrating the exchange of sodium and potassium ions across the membrane (which has come to be recognized as the basic mechanism of nerve impulses).

Eccles progressively elaborated his dualistic model in a series of publications spanning several decades (e.g., Eccles, 1953, 1970, 1977, 1979, 1980, 1983, 1987, 1989; Eccles & Robinson, 1984; Popper & Eccles, 1977).  Eccles felt that it is necessary to postulate the existence of a mind separate from the brain in order to explain the integration of mental activity.  In particular, Eccles felt that the integrated perception of objects and visually presented scenes cannot be explained in terms of known neurological processes, in view of the fact that the nervous impulses related to visual experiences appear to be fragmented and sent to divergent areas of the brain. For instance, Christof Koch and Francis Crick count from 30 to 40 different cortical areas specializing in different aspects of visual processing (Koch & Crick, 1991). Similarly, Wilson, Scalaidhe and Goldman-Rakic (1993) have described the separation of the neurons dealing with the spatial location and identity (color and shape) of an object in the prefrontal cortex of the brain of a monkey.  Hodgson (2005b) notes that red circles are experienced as a whole (or “gestalt”) despite the fact that the neurons “reporting” “red” and “circle” are located in different areas of the brain.

In view of the fact that the perception of any single object involves the firing of neurons in widely dispersed areas of the brain, it is difficult to understand how this neural activity can possibly result in a unified perception of an object.  This conundrum is generally termed the “binding problem” (Koch & Crick, 1991). In Hodgson’s view, the experience of gestalts such as his example of the red circle indicates that consciousness may be nonlocal in the quantum mechanical sense (Hodgson, 2005b).  The relationship between quantum nonlocality and consciousness will be revisited several times in the chapters to follow.

 Stacia Friedman-Hill, Lynn Robertson and Anne Triesman (1995) report an instance in which a breakdown of this perceptual unity was apparent in a patient who miscombined colors and shapes from different objects and who was unable to judge the locations of objects. This patient had bilateral lesions in the parietal-occipital areas of the brain, suggesting that these brain regions may be centrally involved in generating unified perceptions of experience.  

Francis Crick (1994) ascribed the unity of perception to rhythmic oscillations in the brain resulting in the synchronous firing of large populations of neurons.  

Two other neurophysiologists, Gerald Edelman and Giulio Jononi (1995), have contended that the binding of perceptions and the unity of experience is achieved thorough reentrant signaling pathways in the brain.

Eccles, on the other hand, saw the integration of neural activity as the raison d’être of an immaterial mind, and he suggested that the evolution of consciousness may have paralleled the emergence of the visual processing mechanism.  He endorsed William James’ conjecture that brains may have had to acquire conscious minds because they had grown too complex to control themselves.

Eccles proposed that another role of consciousness is to assist in the solving of nonroutine problems (as opposed to the execution of overlearned and routine skills such as tying one’s shoes). Eccles’ view of the role of consciousness is similar to that of many cognitive psychologists in this regard.

Eccles contended that the mind interacts with only certain groups (or “modules”) of neurons, which he called “open neurons.”  He used the term “liaison brain” to refer to the regions of the brain containing these open modules, and he asserted that this liaison brain lies in the cerebral cortex rather than in the deeper areas of the middle brain. In support of this site, he cited a study by Bard (1968) indicating that cats who have had their cerebral cortex removed behave as if they were mindless automata.

In his earlier writings, Eccles maintained that the liaison brain was generally located in the left cerebral hemisphere, due to the fact that language ability is usually located in that hemisphere and the fact that split-brain patients typically report (from the left hemisphere where their language skills are located) that they have experienced no discontinuity in their sense of self following their commisurotomy (an operation that involves severing the corpus callosum, a bundle of nerve fibers that connect the two hemispheres of the brain and provide the primary means for communication between them).

Some evidence in favor of Eccles’ theory that the left brain is the site of consciousness was provided by a study by Efron (1963b) indicating that flashes presented to the left and right visual fields were judged to be simultaneous only when the flash on the left occurred several thousandths of a second before the one on the right, suggesting that the judgment of simultaneity was made on the basis of the simultaneous arrival of the neural messages at a site in the left hemisphere. (Strangely enough, information about the right visual field is sent directly to the left hemisphere and information about the left visual field to the right.)

Another piece of evidence in favor of locating the liaison brain in the left hemisphere is the fact that migraine attacks and brain injuries are more often associated with a loss of consciousness when they occur in the left hemisphere than when they occur in the right (Miller, 1990).

In his earlier writings, Eccles tended to see linguistic ability as a prerequisite for self-consciousness, and he consequently denied self-consciousness to most nonhuman animals and even to the right hemisphere of the human brain following commisurotomy.  He later recanted this position, citing Gallup’s (1977) research demonstrating self-recognition by chimpanzees when confronted by their images in a mirror (they cleaned spots off their faces) and research by Sperry, Zaidel and Zaidel (1979) demonstrating the ability of the right hemisphere in split-brain patients to recognize pictures of themselves (the patients, not the hemispheres!).  Eccles maintained that consciousness is restricted to birds and mammals, the brains of lower animals such as bees and frogs being too small to support consciousness in his view. (Interestingly, Eccles has assigned consciousness to precisely those animals that sleep. Could there be some significance to this?)

In Eccles’ earlier writings, he expressed doubt that influences at the quantum level would be sufficient to explain the influence of the mind on the brain, as he felt that quantum events would be too random to account for the “precisely causal” events in the mind-brain interaction. In his later writings, he changed his mind, observing in particular that the exocytosis of synaptic vesicles (a primary mechanism in the transmission of nervous impulses from one neuron to another) involves energies within the range of the Heisenberg uncertainty principle of quantum mechanics (and thus would allow the mind to influence the brain by determining the outcomes of quantum decisions).  Although Eccles cagily avoided referring to parapsychology in most of his writings, as least on one occasion (Eccles, 1977), he used the word “psychokinesis” to describe the mind’s action on the brain.

The prominent philosopher of science Karl Popper, with whom Eccles wrote his most encyclopedic volume, The Mind and Its Brain, also endorsed a quantum-mechanically based theory of mind-brain interaction; however, at one point in the book Popper suggested that the mind may have its own source of (presumably physical) energy (Popper & Eccles, 1977).  Under this view, the mind would be a sort of quasi-physical object that might be capable of greater influence on the brain than that allowed by the Heisenberg uncertainty principle of quantum mechanics. Thus, the conscious mind proposed by Popper is a powerful one indeed.

Penfield’s theory of mind-brain interaction. Another prominent neurophysiologist to propose a dualistic model of mind-brain interaction in the second half of the twentieth century was Wilder Penfield. The most complete exposition of his model was given in his posthumously published book The Mystery of the Mind (Penfield, 1975).  Unlike Eccles, Penfield did not locate the site of mind-brain interaction in the cerebral cortex, but rather in the evolutionarily older region of the higher brain stem (diencephalon).  (Such a site would make evolutionary sense if immaterial minds are to be attributed to more “primitive” organisms that lack a neocortex.)  As one piece of evidence in favor of this localization, Penfield cited the fact that injury to this site typically removes consciousness and results in a coma.  Interestingly, Penfield did not believe that the site of mind-brain interaction lies in the reticular activating system of the brain stem, despite the fact that injury to this area also produces unconsciousness. This was due in large part to the fact that Penfield assigned a central role to the diencephalon in the integration of brain activity.  In particular, he cited the vast number of two-way connections between the diencephalon and the cerebral cortex as evidence for such a central role. 

The neurophysiologist Robert Thompson agreed with Penfield that the higher brain stem may be centrally involved in integrating behavior.  In support of this assertion, Thompson cited research indicating that injuries to this region produce deficits in a wide range of learning and problem-solving tasks as well as evidence indicating that memories may be stored in this region (Thompson, 1993). 

The physicist Nick Herbert (1993) locates the site of consciousness a bit further down, in the reticular formation of the brain stem.  Herbert sees this area as having a central role in the integration of sensory information and the regulation of behavior.  He sees the cortex as a peripheral device that is not associated with consciousness.

John Eccles (in Popper & Eccles, 1977) explicitly took issue with Penfield’s proposed site of mind-brain interaction, arguing that injury to the brain stem merely removes the background excitation of the cerebral cortex that is necessary for consciousness to occur.   As evidence against Eccles’ localization of the site of mind-brain interaction in the cerebral cortex, Penfield cited the fact that large portions of the cerebral cortex can be removed without loss of consciousness.

As further evidence in support of his proposed site of interaction, Penfield cited the fact that epileptic seizures in the higher brain stem cause a person to behave as a mindless automaton, carrying out preprogrammed motor acts without a later memory of them. Penfield saw conscious attention as a prerequisite to the storing of memories.  In this, he agreed with Eccles, who cited an experiment by Held and Hein demonstrating that active exploration of the environment is associated with learning in kittens, whereas passive exploration (being carried around a room) is not (Eccles, 1979, discussing the experiment reported by Held & Hein, 1963).  However, in cases of multiple personality, secondary personalities seem to be capable of storing memories when the primary personality is distracted or unconscious (although such memories are not generally accessible to the primary personality).

As evidence that the conscious mind lies outside of the brain mechanism, Penfield cites the fact that movements or other activity produced by electrical stimulation of the brain are experienced as ego-alien and involuntary. For example, if Penfield applied an electrical stimulus to a patient’s brain causing her to raise her arm, she typically experienced the raising of the arm to occur independently of her will. Electrical stimulation of the brain never resulted in a sense of volition. (Of course, a materialist could object that this merely proves that the brain can discriminate arm movements initiated by it in an unmolested state from those caused by the application of an outside electrical impulse.) Penfield specifically declined to use the word “immaterial” to describe the mind, perhaps because he viewed such a term as implying a total separation between mind and matter.

Other views on mind-brain interaction. Many other theorists have forwarded their own hypotheses regarding the nature and location of mind-brain interaction. The number of sites proposed is legion, and at times it seems that no area of the brain will prove to be exempt from being designated as the site of the soul.  

V. S. Ramachandran (1980) sees the frontal lobes as the likeliest candidate for the site of mind-brain interaction, partially due to the fact that persons with frontal lobe lesions frequently report a loss of coherence and continuity in their sense of self. 

Joseph LeDoux (1985) equates consciousness with language use and thus associates it with the linguistic apparatus of the brain. He therefore denies consciousness to the right hemisphere in split-brain patients unless it possesses a linguistic capacity, in which case LeDoux would ascribe a dual consciousness to the patient. 

John O’Keefe (1985) sees consciousness as primarily concerned with the construction of mental representations of the world. He would therefore locate consciousness in the septohippocampal region of the brain, insofar as the neurophysiological evidence suggests that “cognitive maps” may be located in this area (certain neurons in a rat’s hippocampus may fire when the rat is in a particular location). O’Keefe also notes that conscious attention is necessary for the storage of episodes and narratives in memory, and certainly the hippocampus must be intact in order that such memories be stored.  Patients with damage to the hippocampal region are generally unable to form new episodic memories. Such a patient may for instance believe he is still a soldier in Korea, having formed no memories of events occurring in the years since he received his head injury.

O’Keefe further notes that consciousness is especially involved in dealing with novel events. The conscious mind, he asserts, selects actions to be carried out, but is not involved in the details of these action programs (such as the specific steps involved in tying a shoe). These action programs instead tend to be automatic and occur outside of awareness. He does note that consciousness is involved in the initial learning of such programs. Conscious attention is also activated when the result of a motor action is unexpected and deviates from the fixed action plan. He observes that certain neurons in the hippocampal area tend to fire when an organism is confronted with a novel situation, which he takes as further support for the hippocampus as the site of consciousness.

Like O’Keefe, David Oakley (1985a, 1985b). asserts that the conscious mind is intimately involved with the creation of cognitive representations of the world. He notes that the hippocampus and neocortex must be intact for such representations to emerge, as opposed to simple conditioned responses.   In an article written with Lesley Eames, Oakley suggests that two or more domains of consciousness may coexist within a single person (Oakely & Eames, 1985). Oakley and Eames note, for instance, that associative learning occurred separately for each of the alternate personalities in the “Jonah” case of multiple personality (Ludwig, Brandsma, Wilbur, Bendfeldt & Jameson,1972), whereas Pavlovian conditioning, which they view as noncortical and automatic, was shared among the different personalities.  Oakely and Eames also attribute a dual consciousness to split brain patients, although they see “self-awareness” as usually being restricted to the left hemisphere.

Benjamin Libet (1989, 1991a) views the supplementary motor area (SMA) of the cerebral cortex as being one of the primary areas that is involved in voluntary acts.  In this he agrees with Eccles, who at one point went so far as to say that “there is strong support for hypothesis that the SMA is the sole recipient area of the brain for mental intentions that lead to voluntary movements” (Eccles, 1983, p. 45).  Libet notes that patients with damaged supplementary motor areas are often incapable of spontaneous voluntary movement; while they may listlessly respond to suggestions from others, they seldom initiate movements on their own. In this sense their will is curtailed. Libet’s view is underscored by Goldberg’s observation that lesions of the supplementary motor area lead to repetitive hand movements, such as buttoning and unbuttoning a shirt, that are experienced as ego-alien and occurring independently of the subject’s will (Goldberg, 1985).  Libet further observes that blood flows into the supplementary motor area when movements are merely being contemplated.

Libet’s own experiments indicate that subjects’ decisions to initiate motor movements (flexing the hand) typically do not occur until 350 milliseconds after a readiness potential has begun to build in the brain, indicating that the brain itself has already been preparing for movement at the time of the subject’s experienced decision.  Libet notes, however, that mind-brain interaction must be a two-way street, and he found that subjects could change their mind about flexing their hands during the final 150 milliseconds preceding the actual physical act.  He also found that this veto decision seemed to coincide in time with a drop in the voltage of the readiness potential.  Libet infers from this that the conscious mind has the ability to block an already initiated movement or to let it occur.  In this view, the brain is seen as generating courses of action, while the mind or a “free will” decides on the options. He sees the inhibition of action as one of the central roles of a conscious mind.  

Levy (2005) has interpreted Libet’s results in a somewhat different manner.  Levy notes that Libet’s subjects may have delegated the task of deciding when to flex their hand to processes occurring in the “unconscious” regions of their minds.  Levy also notes that it is reasonable to doubt whether Libet is correct in identifying the unconscious brain activity with the intention to or decision to act rather than with the generation of an urge or desire to act.

To explicate the process of mind-brain interaction, Libet (1994) postulates the existence of a “conscious mind field” (CMF), which he sees as being produced by brain activity. The CMF is not capable of being detected by physical measuring devices, nor is it reducible to neural processes; nevertheless, Libet proposes that the CMF is capable of exerting a causal influence on brain processes and that it provides the means whereby diverse neural activity can give rise to unified perceptions and experiences. Libet contends that his view of the CMF is compatible with a variety of different philosophical positions on the mind-body problem.  Libet’s views are discussed in more detail in Chapter 7.

The staunch defender of materialism Paul Churchland (1995) has proposed the intralaminar nucleus of the thalamus as the brain site responsible for producing a “unified consciousness.” (Yes, even that ardent proponent of reductionist materialism Paul Churchland has been forced on occasion to use the word “consciousness” in a nonpejorative sense.)  Churchland bases his claim on the fact that this brain site possesses two-way projections to diverse areas of the brain as well as the fact that the various senses are represented polymodally in this area. He notes that his colleague Antonio Damasio (1994) has nominated the right parietal lobe of the brain for a similar role, as this area must be intact in order for a continuous sense of the self to exist.   

Jean Burns (1993) has suggested that the synchronous firing of large assemblies of neurons underlies conscious experience and forms the interface for mind-brain interaction. Burns’ theory is based on brain wave records and recordings from single neurons showing that such synchronous firings are involved in acts of conscious perception.  Burns’ view in this regard is very similar to that of Koch and Crick, discussed above.

Indeed, it would almost seem that no region of the brain has been omitted from the list of brain regions that form the primary center of consciousness according to one researcher or another.  In addition to the candidates listed above we have the thalamus (Cotterill, 1995), nonrandom, coherent deviations of the brain’s electromagnetic field from its resting state (John, 2003), and, last but not least, quantum-mechanically entangled water in the microtubules composing the cytoskeletons of neurons (Penrose, 1994; Hameroff, 1994).  Each of these authors presents a cogent argument in favor of their candidate for the area of the brain (or brain process) that is the center of consciousness (or of the interaction between consciousness and mind).

With this many candidates for the primary center of consciousness (or of interaction between the conscious mind and brain), it may begin to seem that no center is primary, that many different brain centers and processes may be associated with their own conscious activity, and that these centers of consciousness may not be mutually accessible to one another, at least in a direct sense.  This possibility will be discussed in much further detail in Chapters 5 and 7.


Last, but by far not least, there is strangely appealing doctrine of “mysterianism,” whose most notable proponent is Colin McGinn (1999).  McGinn contends that the biological wetware of our brains has evolved to enable us to reason about and understand the physical world rather than to solve such esoteric problems as the nature of consciousness and the fate of the soul.  Our globs of 1011  pulsating amoeba-like neurons are more likely designed to discover how to better secure a stone axe head to a stick to beat upon our neighbor’s brain than to enable us to understand the realms to which our neighbor’s consciousness has fled after we have completed our handiwork.

 In McGinn’s view, the role of consciousness and the nature of the soul will forever remain beyond our cognitive grasp as our primate brains have evolved to seek fruit and elude tigers and deal with other concrete concerns in the physical world.  McGinn opines that the nature of consciousness and its relation to the physical world must remain outside of the grasp of consciousness, at least of those consciousnesses inhabiting our primitive primate brains, which are unequal to the task of understanding their true nature.  Perhaps McGinn is right.  Perhaps that is why consciousness is often referred to as the “hard problem” of philosophy.  But, unlike our ape brethren, we have been to the moon and plumbed the creation of the universe down to the first femtosecond.  It is premature to give up trying to understand the nature of our conscious mind.  As we shall see, such understanding may require us to relinquish core beliefs about the nature of our selves and the quasi-permanence of our association with any particular body.

 Once we have shed our present body and the “self-cocoons” we have wrapped around us to keep us firmly fixed to our present personalities, who knows what wonders may await us? 

2. Mind and the Quantum

Under the theories of physics developed by Isaac Newton that dominated Western thought about the physical world from the late seventeenth to very early twentieth century, the physical world was seen as a great impersonal clockwork mechanism.   Under this classical, Newtonian view, the physical world was deterministic in the sense that, given the present state of the world, including the position and velocity of every single particle of physical matter, the future states of the universe were completely determined by the laws of physics.  Thus, given the (completely described) state of the universe on July 15, 2012, the events of, say, November 23, 2013, are completely determined.    As the mathematician and cosmologist Pierre Simon Laplace put it, a Divine Calculator who knew the position and velocity of every material and particle in the universe could deduce the entire history and future of the universe down to the smallest detail.

 Obviously in such a clockwork universe, there is no room for intervention by a nonphysical mind.  The soul, or atman, had no place in the theory of physics developed by Newton, despite the fact that Newton himself was a devout believer in the Christian God (unless of course the soul were conceived to be a material particle under some type of double-aspect theory).

 All this changed with the development of quantum mechanics around the beginning of the twentieth century.  Under the quantum mechanical view, the world is no longer completely deterministic, even (especially) at the subatomic level.  Given the present state of the universe, under the laws of quantum mechanics, many different futures are possible.  This view of reality opens a crack in the cosmic egg (to borrow a phrase from Joseph Chilton Pearce, 1973) for the influence of a nonmaterial mind or soul to creep into the picture.  

Quantum Nonlocality

 Also, the classical determinism of Newtonian physics saw the world as composed of whirling buzz of mindless submicroscopic particles, careening blindly about in space, sometimes joining and sometime repelling each other, their behavior governed by the impersonal laws of physics.  In this universe there seems only room for the parts and little room for the whole as exemplified in conscious minds that are somehow aware of activity of vast (on the elementary particle scale of things) regions of the brain.  In the classical view of the universe, each particle of matter responds only to its local surroundings.  It does not respond to its compatriot particles until it quite literally “bumps into them.”  This notion that the behavior of physical particles is governed completely by events in their local spacetime regions is called “local realism.”  Despite the deluge of popular books that have been written about quantum mechanics in the second half of the twentieth century (not to mention those published in the infancy of the new millennium), “local realism” is still the view that undergirds our intuitive understanding of the universe, both laymen and scientists alike (although perhaps both groups should know better by now).  

 As noted above, under the theory of quantum mechanics, indeterminism reigns.  Given the present state of the universe, many different futures are possible.  Take, for instance, the case of Schrodinger’s hapless cat, imprisoned in a box together with a radioactive source that will kill it (through some sort of Rube Goldberg device) if a Geiger counter detects a radioactive decay.  After a fixed period of time there is a 50-50 chance that when we open the box we will find a cat that has been sent to that Great Alley in the sky.  According to the standard interpretation of quantum mechanics, the variables that determine the instant of the first decay, if indeed there are any, are “hidden” to us.  The best we can do is compute the probability that the cat is still alive.  If there are “hidden variables” that determine the cat’s fate, we cannot know them.

The most startling and remarkable thing about such hidden variables is that, if they exist, they must be nonlocal in nature.  To understand what “nonlocality” means in this context, consider the case of two protons that are initially united in a state of zero spin (what physicists call the “singlet state”).  Suppose that the protons have become separated from one another and are moving in opposite directions through space.  If the spin of one of these protons is measured along a spatial axis and the proton is found to be spinning “upward” along that axis, the other proton must be spinning “downward” along that axis (as their total spin along any axis must sum to zero).  Thus, it seems that when you measure the spin of one proton and find it to be “up”, the second proton is somehow instantly informed that it should adopt the “down” state on that axis.  

It might be assumed that the Newtonian framework in which the protons are viewed as separate, isolated particles could accommodate this phenomenon through postulating that, when the protons separated, one of them possessed some property that made it spin “down” on the axis and the other one possessed some property that made it spin “up.”  In other words, there is no need to assume any mysterious interconnection between the protons.  This is view under the doctrine known as “local realism.”

 It can be shown that if protons really do posses such local properties, the numbers of proton pairs exhibiting various combinations of spins on certain predefined axes must satisfy a class of inequalities called Bell inequalities after the physicist John Bell, who derived them.  The theory of quantum mechanics, on the other hand, predicts that Bell inequalities will be violated if certain combinations of spatial axes are chosen.  

Against my better judgment, I am not going to force the reader to take my word for it this time, but I am going to walk those readers that able to recall their high school trigonometry through the actual mathematics used to establish that the “hidden variables” of quantum mechanics must be nonlocal in nature.  (They say that each equation a book contains halves its sales.  If so, here go 99.95% of my royalties.)  The math phobic reader may however ignore the equations and inequalities that follow and quite literally “read between the lines” to follow the gist of my argument.  However, for those readers who can follow the actual mathematics, the demonstration of quantum nonlocality is all the more compelling, startling and, to use a hackneyed phrase, awe-inspiring when you appreciate and understand the beauty and simplicity of the mathematics behind it.  The mathematical exposition to follow is roughly along the lines set forth by Bernard d’Espagnat (1979) in his highly lucid explanation of quantum nonlocality.

 We begin our story with two protons blissfully united in the “singlet” state, a state in which their collective spin is zero.  (A proton’s spin may be oversimplistically  imagined as the spin of a top; its units are expressed in term of angular momentum.  Unlike a top, however, the proton is only able to manifest distinct units of spin, unlike a skater who can go smoothly from a slowly spinning state with her arms extended to a fast-spinning state with her arms pulled in or slowly turn a clockwise rotation into a counterclockwise rotation.  In quantum mechanics, these states are discrete; there is no intermediate spin in which the spinner’s arms are half pulled in so that she is spilling at an intermediate rate.  A proton goes directly from one spin state to another in what is often termed a quantum leap.  The proton, like all free quantum spirits but unlike skaters, also may be found in a mixture of states in which it is spinning “clockwise” (also known as “downward”) with probability, say, 0.6 and spinning counterclockwise with a probability of 0.4.

 Thus, in quantum theory, the properties of material particles are not specified deterministically, but only probabilistically.  For instance, one may measure the spin of a proton along any spatial axis A of one’s choosing, and its spin will be found either to be in the upward direction with regard to that axis (A+) or in the downward direction along that axis (A-).  The quantum mechanical description of the particle’s state does not determine the spin direction along any axis, but only gives the probabilities that the spin will be found to be either “up” or “down” with regard to the given axis.  

 If the quantum mechanical description is complete, then the proton does not have any definite, well-defined spin with regard to any axis until a measurement is made, after which the proton’s spin will either be up upward along the axis or downward along the axis.    If the spin of a proton along any particular axis A has been measured, its spin along any other axis B is indeterminate according to quantum theory.  The proton is said to be in a “superposition” of the “spinning upward on B” and “spinning downward on B” states.  The proton is not definitely in one state or the other, and quantum theory can only yield the probability that it will be found to be spinning upward on B rather than being able to predict in advance which way the proton will be found to be spinning when measured along axis B.

At the point of measurement or observation, the proton acquires a definite spin on axis B, through a process known as “the collapse of the state vector.”  The nature of this process is not adequately specified by quantum theory, and state vector collapse seems to be due to factors not adequately defined in present day quantum theory.  

The lack of any provision for the state vector collapse in the formalism of quantum mechanics formed the inspiration for Hugh Everett’s Many-World, interpretation of quantum mechanics in which all possible outcomes of quantum mechanical processes are postulated to occur in some alternate future (Everett, 1957).  Thus, there may alternate universes alongside of ours in which you are no longer a quadriplegic because President Al Gore’s Secretary of Transportation enacted policies leading to schedule changes in your local bus service so that the bus did not locate itself in the same spacetime region as your body when you stopped to tie your shoe on April 1, 2003.  Under Everett’s Many World hypothesis, all events that are possible under the laws of quantum mechanics actually occur in some alternative future.

Many theorists (e.g., Wheeler, 1983; Walker, 2000) have proposed that observation by a conscious mind, an entity outside of physical science altogether (barring the truth of reductive physicalism), may be necessary to force state vector collapse and to ensure that only one of the many futures allowable under quantum mechanics actually occurs.

If a proton’s spin is determined (through measurement) along one axis, its spin along any other axis is undetermined according to quantum theory and does not take on any definite value until an act of observation occurs.  Einstein, Podolsky and Rosen (1935) argued that quantum theory is simply incomplete in this regard.  For instance, it may be possible in some sense to measure the spin of a proton along two directions at once.  If two protons are initially united in a state of zero spin (e.g., the “singlet” state) and then allowed to separate, their spins as subsequently measured on any chosen axis must have opposite values.  Thus, if the spin of the first proton is measured to be upward along an axis A (A+) and its partner’s spin measured to be upward along a second axis B (B+), it can be argued that the first proton must have been an A+B proton (i.e., having properties causing it to spin upward on the A axis and downward on the B axis) prior to the act of observation.

Thus, Einstein, Podolsky and Rosen argued, particles do have definite properties prior to any act of measurement and the probabilistic description provided by quantum theory is simply an incomplete description of reality.

John Bell (1964), on the other hand, was able to use a simple mathematical argument to show that the empirical predictions of quantum theory are in conflict with any theory assuming that the outcome of quantum measurements are determined by the local properties of particles and do not depend on what occurs in distant regions of space.

A simplified version of Bell’s argument is as follows.  Assume that protons have localized properties that determine the outcomes of spin measurements (i.e., the proton has “really” been spinning upward on the A axis all along, although we didn’t know it until we observed it).  An A+B proton would then be a proton that has a property that ensures that it will be found to be spinning upward when measured along axis A and downward if measured along axis  B.  Such A+Bprotons must come in two varieties: those that will be found to be spinning upward when measures along any third axis C (the A+BC+ protons), and those that will be found to be spinning downward when measured along axis C (the A+BC protons).  Thus, the probability p(A+B) that a proton will have spins A+ and B must therefore satisfy the  following equation:

 p(A+B) = p(A+BC+) + p(A+BC)     (2.1)

By a similar reasoning process, we have:

 p(A+C) = p(A+B+C-) + p(A+BC)     (2.2)

But as p(A+BC) is greater than or equal to 0, Equation (2.2) implies:

 p(A+C)p(A+BC)       (2.3)


  p(BC+) p(A+BC+)       (2.4)

Adding inequalities (2.3) and (2.4), we obtain:

  p(A+C) + p(BC+)p(A+BC) + p(A+BC+)   (2.5)

Substituting from equation (2.1), we have:

  p(A+C) + p(BC+)p(A+B)     (2.6)

Inequality (2.6) is known as a Bell inequality, and it must be obeyed if the proton’s spins are determined by local properties of the protons themselves and do not depend on events happening in remote regions of space and time.  Inequality (2.6) is, however, in conflict with the predictions of quantum theory.  According to quantum theory, if the positive directions of two axes A and B are separated by an angle φAB, the probability that a proton will display opposite spin orientations on the two axes is given by sin2(φAB /2).   As either the A+B or the  A-B+ orientations are equally likely given the singlet state, we have:

  p(A+B) = 1/2 X sin2(φAB /2)      (2.7)

 Suppose we orient detector A so that the positive pole points in the “north” direction (in a plane).  Suppose also that we point detector B in the “southeast” direction and detector C in the “northeast” direction (in the same plane).  Then we have φAB = 135oφAC = 45o, φBC = 90o.  (Now is the time to reach back into your memory for whatever tidbits of high school trigonometry may be remaining there or, better yet, to dust off that scientific calculator you have been keeping in the attic.)

 Using the probabilistic laws of quantum mechanics as described above, we have:

p(A+C) = 1/2 X sin2(45o /2)  = 1/2 X sin2(22.5o) = .073  (2.8)

p(BC+) = 1/2 X sin2(90o /2)  = 1/2 X sin2(45o) = .250  (2.9)

p(A+B) = 1/2 X sin2(135o /2) = 1/2 X sin2(67.5o) = .427  (2.10)

 These probabilities are in violation of the Bell inequality (2.6), as can be seen by substituting the values given in equations (2.8) through (2.10) into inequality (2.6) to obtain:

  .073 + .250 ≥ .427       (2.11)

 Inequality (2.11) is obviously false, thus revealing that the laws of quantum mechanics are in conflict with the philosophy of “local realism” from which inequality (2.6) was derived (i.e., the view that the outcomes of quantum measurements are determined by properties of the particles and the local spacetime regions in which they reside).

 Experimental evidence by Alain Aspect and his coworkers (e.g., Aspect, Dalibard,  & Roger, 1982) has shown that in a test of quantum mechanics against local realism, the Bell inequalities are violated, and the evidence is strongly against the doctrine of local realism.  It should be noted that Aspect’s experiments were conducted using photons rather than protons, and the mathematics underlying the Bell inequalities is somewhat different and a little more complex than that for protons.  A very readable exposition of the mathematics underlying Bell inequalities for photons is given in McAdam (2003). 

Aspect et. al’s results imply that two quantum particles such as protons may not be the isolated objects separated from each other in space that they appear to be.   Instead, they may form one united system even though they may be separated by light years of space.  The protons do not have defined spins on a spatial axis until a measurement of one of their spins along that axis is made, at which point the measured proton’s partner suddenly adopts the opposite spin.  After the first proton “chooses” a spin (up or down) along the measured axis, the second proton is somehow mysteriously informed that it should adopt the opposite spin if measured along that same axis.  It cannot be the case that the first proton manages to send a message to the second proton telling it which spin to adopt, as the protons may be sufficiently far apart that no such signal could be sent between them unless it exceeded the speed of light, which is regarded as impossible in standard theories of physics.  Thus, the protons, two seemingly separated and isolated little billiard balls, turn out not to be separated from one another after all. 

 Even single physical particles are not the localized, isolated entities that they appear to be.  Consider the case of the classic “double-slit” experiment, in which electrons must pass though one of two slits in order to reach a detecting mechanism.  Electrons are always detected as point-like entities; thus, it is reasonable to assume that the distribution of the locations of electrons detected when both slits are open will simply be the sum of the distributions obtained when the slits are opened one at a time.  However, as streams of electrons possess wavelike properties, an interference pattern (bands of darkness and light) will be manifested at the detecting device when both slits are open, and this interference pattern will differ markedly from the distribution expected by summing the distributions obtained when the slits are opened one at a time.  The most amazing thing is that the interference effect manifests itself even under conditions in which only one electron can pass through the diffraction grating at a time.  Thus, it appears that a single electron somehow manages to go through both slits at once!  Any attempt to determine which slit is actually traversed by the electron reveals, on the other hand, that the electron passes through only one slit.  Furthermore, this determination destroys the interference pattern and results in a distribution equal to the sum of the distributions from each slit.

 Thus, although an electron is always detected as a point-like entity, it appears to manifest itself as a nonlocalized wave function under circumstances in which we do not attempt to determine its location.  The modern interpretation of this wave is that it is a “probability wave” existing in an abstract mathematical space called Hilbert space rather than in physical space.  The electron, an apparently solid point-like entity when we observe it, is apparently a ghostly vibration in an abstract, almost mind-like, space when we are not looking!

 Chris Clarke (2004) notes that the phenomenon of quantum nonlocality as demonstrated in Aspect’s experiments strikes the death knell for the philosophy of atomism (the notion that one must look to the scale of the universe’s smallest particles in order to find ultimate reality).  He notes that atomistic and mechanistic metaphors lead to dualistic approaches to the “mind-body” problem such as those derivative from Descartes’ model, rather than to an approach that would truly integrate the mental and physical worlds.  Clark concludes that contemporary physics cannot provide any sort of ultimate reality at all, although it points the way to a more complete understanding of reality.

Quantum Holism.

Science has generally proceeded by the analysis and dissection of complex systems into their parts, the ultimate parts being of course elementary particles such as electrons and quarks. Higher order phenomena, such as the activities of the mind, are to be explained in terms of lower order entities such as molecules and electrons, at least according to the “orthodox” (that is, outmoded Newtonian) view of the world. This type of explanation is known as “upward causation.” The philosophy upon which it is based is called “reductionism,” as it assumes that the properties of complex systems, such as people, can be reduced to the properties of their components (such as atoms). 

Indeed, as we have seen, even the behavior of our two entwined protons, seemingly the simplest of physical systems, is not governed by their local properties but rather by the more encompassing system that includes them both.

The physicist David Bohm (Bohm, 1980; Bohm & Peat, 1987) has referred to the universe as a “holomovement,” invoking an analogy to a hologram (a three dimensional photograph in which the entire picture may be reconstituted from each part).  Bohm has termed the world of manifest phenomena or appearances the “explicate order” and the hidden (nonlocal) reality underlying it the “implicate order.”  Bohm laments the tendency of modern science to fragment and dissect the universe and to focus on parts rather than wholes. He proposes a new mode of speaking in which “thing” expressions would be replaced by “event” expressions. 

 The philosopher Hoyt Edge (1980a, 1985) has called for the abandonment of the localized “entity” metaphysics and the adoption of an “activity meta-physics,” in which reality would not be seen as separated into physical or mental atoms and the dichotomy between the observer and what is observed would be abandoned.

K. Ramakrishna Rao (1978) has noted the similarity of both Bohm’s concept of an implicate order (in which all events are interconnected) underlying the manifest world as well as Karl Pribram’s view of the world as a hologram, in which the whole universe is seen as somehow contained in or related to each of its parts (Pribram, 1971, 1978), to the Vedantic doctrine of the identity between atman (or a person’s individual consciousness) and Brahman (the Supreme Self or World Mind). Transcendental and mystical states of consciousness may involve the direct experience of Brahman in Rao’s view.  

Based in part on quantum mechanical considerations, astrophysicist David Darling (1995) proposes that our individual, encapsulated egos are illusions and that, when a person dies, this illusory self is dissolved and the person’s consciousness merges with the world consciousness (or Brahman, in Rao’s terminology).

 Victor Mansfield (1995), echoing Rao, sees the concept of emptiness in Middle Way Buddhism as being akin to the concept of nonlocality in quantum mechanics.  Mansfield notes that according to the doctrines of this school of Buddhism, objects do not exist independently of the mind.

Like Bohm, Herms Romijn (1997), a researcher at the Netherlands Institute for Brain Research in Amsterdam, proposes that there exists a submanifest deterministic order underlying all observed phenomena in the universe.  He proposes a version of the “double-aspect theory” in which all matter in the universe is seen as being imbued with consciousness.

In a similar vein, the physicist Evan Harris Walker (2000) has proposed that all observers are in fact one and that this single observer is responsible for the collapse of all quantum mechanical state vectors.  Walker, like Eccles, Stapp and many other mind-brain theorists, proposes that the mind acts on the body through determining the outcome of quantum processes in the brain.

Consciousness and Quantum Collapse.

 There is no provision within the theory of quantum mechanics itself for the collapse of the quantum probability vector into a definite outcome.   According to the theory of quantum mechanics, the quantum probability wave will be happy to go on deterministically evolving, never settling in to a definite outcome.  But we do not experience the world as a fuzzy blob of half-dead / half-alive Schrödinger’s cats.  When we open the box, we observe either a live cat or a dead cat.  

Many observers ascribe the collapse of the state vector to the act of observation itself.  To some, this means that it is observation by a conscious mind that forces the quantum vector to collapse and take on a definite outcome.  In a “speciesist” version of this theory, the cat will be suspended in a mix of the alive and dead states until a human observer opens the box, at which point the quantum vector will collapse and the cat will assume either the alive state or the dead state and will remain in the state, to misquote Poe’s raven, “evermore” (so long as we either keep bringing food and water and providing it the most advanced feline geriatric care or, in the nonfavorable scenario, make no attempts at a Frankensteinesque revival).  To a nonspeciesist observer, however, observation by the cat’s conscious mind would be sufficient to collapse the state vector.  To exalt the human mind as the only conscious agent capable of collapsing state vectors in to commit the same act of hubris as our ancestors who place the earth at the center of the universe and proclaimed man to be the divine ruler over all beasts.  Human beings, despite their industrious natures, cannot be all places at all times.  In fact, we have only been around for a lousy few million years, which is but a blink of an eye in comparison to the 13.5 billion years our universe (or local portion of a much vaster “multiverse’) has been around.  In that time, we have been confined to a nondescript (but thankfully wet) piece of rock in the boondocks of a galaxy that is not particularly distinguished from the myriad other galaxies that float through our cosmos.

   Try though we might, human beings (and animals for that matter) cannot be everywhere at all times.  A quantum-collapsing consciousness’s work is never done.  This is why some theorists, such as Walker (2000), have postulated that the universe comes complete with “proto-consciousnesses” that collapse quantum vectors in regions of space and time that are remote from human presence.  (And, if such conscious observers are out there in the “void,” they are likely to be here among us as well.)  These are the considerations that led Hill (2005) to propose that, from the looks of things, the universe is devised for creatures or consciousnesses that inhabit the vast, inhabitable regions of outer space.  Could Hill’s beings and Walker’s proto-consciousnesses be one and the same?

The view that quantum collapse is brought about through observation by consciousness has led Henry Stapp (2005a) to proclaim that quantum mechanics replaces the material world with a world of experience.  Indeed, if conscious minds are what force quantum processes to assume a definite outcome, it may be that mind plays a fundamental role in the process of “becoming,” the process whereby an undetermined future becomes the experienced present and then the determined past.  Perhaps consciousness is responsible for the flow of time, the process by which the future becomes the “now” and then recedes ever more distantly into the past.  Theories of physics are at a loss to explain the phenomenon of the “moving present” that treks its way into the future at a paradoxical speed of “one second per second.”  Physicists dismiss the concept (and experience) of “time flow” as subjective, and hence (perhaps like consciousness itself) not worthy of serious consideration.  And yet still, Time’s finger, having writ, moves on.  If conscious minds are the major players in generating the flow of time and determining the location of the “present” (a concept denied in relativistic physics) along the axis of time, then role of consciousness in the cosmos may be truly fundamental.

While the view that acts of observation by conscious observers are what cause quantum probability vectors to collapse to a definite outcome is a common one, not all quantum physicists subscribe to that view.  Some scientists assert that a recording of the outcome on a macroscopic recording device (e.g., computer printout) is sufficient to cause collapse.  However, technically speaking, the deterministically evolving quantum probability function applies to such macroscopic systems and there is no provision for collapse within quantum theory itself.  Such macroscopic recording devices could exist in a state of undecided superposition until Hell freezes over (i.e., about 10100 years from now, but not to worry) as far as the laws of quantum mechanics are concerned.

Other quantum theorists assert that at reasonably warm temperatures (say, -200 Co), the quantum waves of macroscopic outcomes (such as the breaking or non-breaking of the glass vial of cyanide and the last few pages of the autobiography of Schrödinger’s unfortunate cat) cannot remain in a state of superposition due to interactions with external systems.  Penrose (1994), for instance, hypothesizes that when a physical system reaches a certain mass, it can no longer remain in a state of quantum indecision (superposition), as the effects of gravity come into play.

Other physicists (e.g., Hugh Everett, 1957) take the “easy” way out and deny that quantum collapse occurs.  Under Everett’s “many worlds” interpretation of quantum mechanics, all possible outcomes of a quantum process occur, which fractures the universe into multiple worlds at each moment of a quantum decision.  If Lee Harvey Oswald had flipped a quantum mechanical coin to decide whether to enter the Marines to receive rifle training or become a scuba diver instead, there might now be a parallel universe existing alongside of ours (in an abstract mathematical space called Hilbert space) in which Oswald receives his demise, not at the hands of a crazed Jack Ruby seeking to avenge the death of President Kennedy, but rather in the mouth of famished great white shark.  Of course there are countless quantum decisions taking place at each instant of time, so every second the universe we reside in splits into a (literally and mathematically) uncountable infinity of universes existing alongside each other in Hilbert space.  Unfortunately, however, there is no way for us (at least at present) to leave our mundane universe and travel through Hilbert space to catch up with the fascinating adventures of our other selves in these parallel worlds.  Most physicists think that the countless multiplying of universes in Everett’s “many worlds” interpretation of quantum mechanics is simply too uneconomical (in terms of the number of unobservable universes that must exist) and too fantastic to be taken seriously.  However, Everett’s model does have the beauty of not having to account for what causes the collapse of quantum mechanical state vectors.  They simply don’t collapse.

The Mind’s Influence on Quantum Outcomes

As well as causing the collapse of quantum mechanical state vectors, there is a smattering of evidence that the mind can influence the outcomes of such collapse.  This evidence is controversial and has not as yet been accepted by the majority of the scientific community, but rather falls under the rubric of parapsychology.

A series of experiments directed at detecting the psychokinetic (“mind over matter”) influence of such quantum events as radioactive decay, begun by Helmut Schmidt in the 1960s and since continued by many other investigators, has been quite successful by parapsychological standards (e.g., Schmidt, 1970, 1976, 1981,1984 1985, 1986, 1993).  In a typical such experiment, a subject might be given the task of increasing the number of radioactive decays in a sample of strontium-90 that occur during odd microseconds rather than even microseconds.  Schmidt’s typical finding is that subjects are able to slightly to increase the number of events that are in line with their goal (e.g., decays detected during odd microseconds rather than even microseconds).  The typical effect is a slight bias in the target direction (e.g., 50.3% of decays detected during an odd microsecond vs. the 50% that would be expected by chance according to the laws of quantum mechanics).  However, owing to the large number of trials, the odds against even such a small deviation happening by chance are generally quite large (on the order of a million to one). This line of evidence directly suggests that the mind may indeed be the source of the some of the hidden variables that govern the outcomes of quantum processes.  A more detailed discussion of the nature and strength of the experimental evidence for such parapsychological phenomena as psychokinesis, precognition and telepathy will be postponed until Chapter 4.

One of Schmidt’s more intriguing findings is his evidence for retroactive psychokinesis (e.g., Schmidt, 1976, 1981, 1985, 1993).  In such an experiment, a series of quantum events is recorded in a computer’s memory bank, but not observed by anyone.  At some time in the future, a human (or animal) subject is asked to influence these events, which would normally be regarded as falling into the fixed past.  Schmidt and his coworkers have found such observers to be successful in their attempts to manipulate the past.   Thus, if acts of conscious observation are indeed the cause of “time flow,” it seems that events of last week, already stored on a computer, may still be part of the “future” until they are consciously observed and the quantum mechanical state vector collapsed to a specific outcome.  Incidentally, the same effect is obtained in more orthodox areas in physics.  For instance, light emitted from a quasar billions of years ago may be “gravitationally lensed” by a galaxy sitting between the Earth and quasar, producing a double-image of the quasar.  Much like the quantum mechanical “two slit” experiment with electrons described above, a decision to observe whether the light took the “left” or “right” path around the galaxy, will show no interference pattern, only the bimodal “two humped” distribution one would expect from photons following one path or another.  A decision not to monitor the path, will result in the typical interference pattern suggesting that the photon (or its quantum state vector) somehow took both paths.  Thus, a decision as to the type of measurement to be made in the present may seemingly influence events happening billions of years ago, suggesting that these events in the infancy of the universe may be part of the as yet to be determined “future” until they are observed by a conscious entity.

Quanta and the Mind

 Many scientists have proposed that the mind acts on the brain through the influence of quantum processes.  The views of Hameroff, Penrose, and Eccles have been discussed in the previous chapter.  Another prominent theorist to propose such a view is the physicist Evan Harris Walker (Walker, 1975, 1984, 2000, 2003), who, like Schmidt, has also developed mathematical theories regarding psychokinetic effects on quantum processes. 

 Walker asserts that the quantum probability wave (i.e., state vector) constitutes a complete description of the physical system of the brain, but does not specify the outcomes of quantum processes.  He asserts that the conscious mind, or “will” in Walker’s terminology, corresponds to the “hidden variables” that determine the outcomes of quantum events.  As the will falls outside of the physical description of the brain, it is nonphysical in Walker’s view.  He further asserts that the will is nonlocal and atemporal (not located at a particular instant of time).  He hypothesizes that the will has a channel capacity (ability to influence events) of 6 X 104 bits per second.  However, in Walker’s view, the will is far from being all-powerful as it is embedded in a physical system processing 5 X 107 bits per second.

 Bierman and Walker (2003) report some empirical evidence in support of Walker’s theory.  Specifically, they report a difference in brain waves between human subjects who were the first to observe a quantum event and those who observed outcomes of quantum mechanical events that had already been observed by another human observer.  They note that their results go counter to an earlier finding by Hall, Kim, McElroy and Shimoni (1977) that subjects could not guess which quantum events had been observed previously.  Bierman and Walker argue that the inter-observational interval was too short in Hall et. al.’s experiment for the first observer to consciously perceive the outcome, citing Libet’s finding that 300-500 milliseconds of brain activity is required before a stimulus is consciously perceived (Libet, 1991b).  Bierman and Walker found a difference in brain waves between subjects who observed “new” and “preobserved” quantum outcomes in the first 100 milliseconds of brain activity, but no differences in the late brain potentials (after 1000 milliseconds).  Bierman and Walker note that their failure to find an effect of preobservation in the late evoked brain potentials of their subjects is consistent with Hall et al.’s finding of no conscious differences in the perceptions of “new” and preobserved quantum processes.

 A somewhat more passive view of the mind’s role in influencing the outcomes of quantum mechanical processes in the brain, at least in terms of its timing, is proposed by the theoretical physicist Henry Stapp (2004, 2005b).  As discussed in the previous chapter, Stapp postulates that the conscious mind waits for the quantum probability wave to favor a desired outcome and then stabilizes it.  This would involve an ability on the part of fields of consciousness to sense the mathematically abstract quantum wave function and then to stabilize that function through continued observation.   This is a somewhat more esoteric level of influence than the more or less direct influence on the physical processes themselves proposed by Walker and others.

 It should be noted that many of the theories and empirical findings regarding the mind’s influence on quantum mechanics discussed in the preceding passages fall outside of mainstream science.  In particular, the findings of Schmidt and others that conscious minds may influence the outcomes of quantum processes occurring outside of the subject’s physical body are controversial, have not been universally (or easily) replicated, and have been relegated to the outcast field of parapsychology, a field whose status in regard to the mainstream scientific community is marginal at best.  The mainstream scientific/philosophical community has been somewhat more receptive to notion that the conscious minds may influence quantum processes within the brains in which they are (however temporarily) imprisoned.  Thus, despite Bell’s and Aspect’s demonstrations of quantum nonlocality, most scientists/philosophers operating at the fringes (but within the borders) of mainstream science are more comfortable with the idea that the mind’s action is confined to the physical brain than with the notion that its influence may extend beyond the borders of the physical body.  Of course, those physicalists who are deeply embedded within the orthodox core of mainstream science would deny the mind any influence on quantum mechanical processes at all, even those within the physical brain it inhabits.  

 It should be noted that the hypotheses as to the nature and eventual fate of one’s essential self set forth in Chapter 0 are in no way dependent on the existence of the paranormal phenomena studied by parapsychologists.  Neither are they dependent on the hypothesis that the conscious mind directly influences the outcomes of quantum processes in a way that would be incompatible with the laws of physical science.  (There also may be physical or quasiphysical processes yet to be discovered that may have a considerable bearing on this debate.  The vast majority of scientists and philosophers have, in all historical eras, basked in their supreme confidence that their knowledge of the world was essentially complete.  It has never been so in the past, and there is no good reason to believe it is now.) 

 It is, however, to the study of alleged paranormal such as precognition and psychokinesis that we turn in the next two chapters, because of their importance in the contemporary debate of the nature of the mind and the self.  In Chapter 5, we will consider the implications of psi phenomena, if they exist, for our understanding of the fundamental nature of reality.  In Chapter 6, we will consider the evidence that, not just the self, but some aspects of the personality, survive the death of the physical brain.  



3. The Evidence for Psi: Spontaneous Phenomena

This chapter and the next will examine the evidence for psi phenomena such as telepathy (direct mind-to-mind, or at least brain-to-brain, communication), precognition (the ability to “see” the future), clairvoyance (the ability to gain direct knowledge of a physical object by means other than the recognized physical senses) and psychokinesis  (the ability of mind to directly influence matter remote from the physical body).  Collectively, these ostensible phenomena are called “psi phenomena,” a term introduced by the parapsychologists Robert Thouless and B. P. Wiesner (Thouless & Wiesner, 1948; Wiesner & Thouless, 1942).

As the reader is no doubt aware, there is a vast (or, by orthodox science standards, moderately large) literature regarding attempts to demonstrate the existence of paranormal phenomena such as extrasensory perception (ESP) and psychokinesis (PK) in experimental studies.    As will be discussed in detail in the next chapter, there is a great deal of controversy surrounding this literature.  Many observers within the field of parapsychology contend that the existence of psi phenomena has been conclusively established and that the task of experimental parapsychology should now be to explore the nature of psi and the conditions that facilitate or inhibit the expression of psi rather than to amass further evidence that such phenomena exist.  Skeptics, who comprise the vast majority of the orthodox scientific community, assert that that the existence of psi phenomena has not been conclusively established and that the existing body of experimental evidence for psi can be explained away by a combination of procedural and statistical flaws or outright fraud.

We will discuss this controversy in considerable depth in the next chapter.  To do so now would be getting ahead of our story and putting the cart in front of the horse.  The true story begins with a discussion of apparent instances of psi that occur in everyday life outside of the laboratory.  Such cases of “spontaneous psi” have occurred throughout recorded history.  Studies of such cases preceded experimental investigations of psi and formed the rationale and motivation for experimental investigations.

Spontaneous Psi

Classification into Subtypes

One of the foremost investigators of spontaneous psi phenomena was Dr. Louisa Rhine, the wife and colleague of Dr. J. B. Rhine, the man who is widely regarded as the founder of the field of experimental parapsychology.  Over a period of several decades, she amassed a vast collection of over 10,000 cases of apparently paranormal events, which were mailed to her, often in response to articles in the popular press, over a period of several decades. Her anecdotal, theoretical and statistical studies of such cases led to a long list of publications, spanning several decades (e.g., Rhine, 1951, 1955, 1961, 1962a, 1962b, 1963, 1970, 1977, 1978, 1981).  She partitioned the experiences suggesting the operation of an ESP capacity into four main groups: hallucinatory experiences, intuitive experiences, realistic dreams and unrealistic dreams. She established a fifth, “wastebasket” category of “indeterminate type” for experiences that were difficult to assign unambiguously to one of the four previously mentioned categories. Cases involving hallucinations while falling asleep (hypnagogic imagery) or while waking up (hypnopompic imagery) might fall into this indeterminate category, along with cases involving mixed features.

 Hallucinatory cases sometimes involve auditory, tactile, or olfactory hallucinations.  However, visual hallucinations are by far the most predominant mode in such cases (unlike in schizophrenia, where auditory hallucinations predominate).  One famous subcategory of visual hallucinations comprises  “crisis apparitions,” in which someone has a vision of another person at the time that the appearing person is undergoing a crisis (often death).  Such crisis apparitions were a predominant interest of the earliest psychical researchers (e.g., Gurney, Myers and Podmore, 1886a, 1886b), who viewed such hallucinations as possible instances of ghosts or “astral bodies” come to bid their friends farewell (although many observers, such as Edmund Gurney, proposed that such visions were in fact hallucinations induced by paranormal awareness of the crisis being experienced by the appearing person, rather than an actual appearance of the departing spirit of the appearing person).

 Intuitive cases involve a sense of foreboding or “hunch” that something has occurred.  For instance, a woman may be driving to work and be overcome with a sense of foreboding that something is wrong at home.  She turns her car around and drives back to her house, only to find it on fire, her toddler and babysitter huddled on the front lawn.  

 Lousia Rhine’s third category of spontaneous ESP experience was that of realistic dreams.  Such dreams involve a more or less literal and accurate portrayal of the confirming event.  Unlike intuitive experiences, which primarily involve contemporaneous events, dreams are more often precognitive, that is to say involve events that have yet to happen at the time of the dream.  For instance, a mother may dream that her son is a fiery car crash on the night before the actual crash occurs.

 Rhine’s fourth category is that of “unrealistic” dreams, which appear to represent events symbolically rather than literally.  For instance, rather than dreaming of the car crash in more or less realistic detail, the woman in the last example might dream that her son hands her a single rose and then begins walking into a dark cave.  

 Louisa Rhine employed a fifth “wastebasket category” of cases involving mixed features.

 Several types of spontaneous ESP experiences appear to be left out of Rhine’s categorization scheme.  The most prominent of these is the “psi-mediated instrumental response” (PMIR) discussed by Rex Stanford (1974, 1990a).  A case of PMIR might involve a man’s sudden impulse to enter the art museum he normally walks past on his way home from work.  Once inside, he runs into an old flame who lives in another country but who is now on vacation and touring the gallery.  This case could be an instance of psi powers operating at a wholly subconscious level, in which the man became clairvoyantly aware of his old girlfriend’s presence in the art galley, with this subconscious awareness giving rise to the impulse to enter the art gallery.  This category of spontaneous psi would seem to fall outside of Louisa Rhine’s categories of ESP experiences, all of which involve a more or less conscious awareness of the psi message.

 Another category of receptive psi seemingly missed by Louisa Rhine’s classification scheme is the phenomenon of psi-trailing, in which a animal pet animal is lost at distant location yet is able to find its way home (in some instances, even if the pet’s owner has moved to a new location previously unknown to the pet).  Instances of psi-trailing were studied by the Rhines’ daughter, Sally Feather (Rhine & Feather, 1962).

 Another phenomenon suggestive of operation of psi is the common experience of déjà vu, in which a person has the sense that the events she is currently experiencing are strangely familiar and that she has already experienced them at least once before.  One possible explanation of the déjà vu experience is that the person has precognized the events in question, possibly in a dream that has since been forgotten.  Alternative explanations for the phenomenon of déjà vu that do not involve psi powers abound and will be discussed below.

 Some spontaneous cases involve puzzling physical effects such as clocks that stop or portraits that fall off the wall at the time of a persons’ death.  There are also cases that involve anomalous physical phenomena that occur repeatedly over a longer time period.  These are known as poltergeist cases or, in the parapsychologists’ parlance, recurrent spontaneous psychokinesis (or RSPK for short).  Poltergeist cases may involve anomalously moving objects such as cups that fly off the kitchen counter or rocks that pummel the house from outside as well as strange behavior of electrical apparatus, such as radios that seem to turn themselves on or phones that malfunction in odd ways.  Even stranger phenomena have been reported, including bite marks appearing on a victim’s skin.  While the term “poltergeist” literally translates as “noisy ghost,” most modern observers attribute poltergeist phenomena to living agents.  In a typical poltergeist case, there is a “focal person” or “poltergeist agent” involved.  Anomalous physical phenomena generally occur in close proximity to the focal person and few, if any, phenomena are observed in the focal person’s absence.  For this reason, the RSPK effects are generally thought to be caused either through the focal person’s psychokinetic powers or through fraudulent behavior on the part of the focal person.

Examples of Spontaneous Psi

Having outlined the major categories of spontaneous psi, I will now present examples of each of the major subtypes listed above.

Hallucinatory Experiences. 

 Hallucinatory experiences are perhaps the most dramatic category of spontaneous experiences that are suggestive of the operation of ESP.  They may involve visions of persons at the time of death (crisis apparitions), auditory hallucinations (often of a voice calling one’s name), and even olfactory and tactile hallucinations.  

McKenzie (1995) reports a case involving a seemingly precognitive vision of a fatal fire.  On October 27, 1971, a six-year-old boy reported seeing a fire out of the front window of his aunt’s house.  According to his aunt, the boy shouted, “Look at that fire over there - get some water quick!”  The aunt went to the window and saw nothing and took the boy home because she thought that he must be tired.  

The boy’s sister, then nine, corroborated this story, saying that she had gone to her uncle’s house after school on that day and her brother was looking out of this window at the house across the street at about 3:30 PM on October 27.  She stated that her brother had a vision of the house being on fire, including fire engines and stretchers being brought out of the house with the bodies covered by blankets.  She noted that it seemed to be nighttime in the boy’s vision, as he stated that it was dark outside.  She stated that her brother ran out into the street and urged his uncle to get some water.  She stated that her brother then ran home and later got smacked for making up stories.  (Note that this account is at variance with the aunt’s on this point.  This indicates that not all the witnesses’ memories have remained perfectly intact and undistorted between 1971 and McKenzie’s interviews in 1995.).

The boy himself (by then of course a man) reported to MacKenzie that he was looking through the window of his uncle’s house and saw the house across the street on fire.  He said that he could see a pram under the window, with glass and wood falling into it.  He could hear people screaming and could see smoke. He states that, though it was daylight in reality, the events seemed to be taking place at night.  He said that he called his uncle, but by the time he had looked out, the scene had reverted back to normal.   He said that he was smacked for telling lies and that the actual fire happened the next evening.  (A report in the October 28, 1971 number of the Bolton Evening News, the local evening newspaper, confirms that a fire in the house in question did take place.  The blaze was described as an inferno, and two brothers, aged two and three, perished in the conflagration.  MacKenzie notes that it is odd that the fire is described as having occurred “today” in the account in the evening newspaper.  He speculates that the paper was a very late edition or that the fire had in fact occurred the previous evening.

That the fire occurred at night was corroborated by the boy’s father, who stated that his son had in fact run into his shop on the afternoon of the day in question, talking about the fire and telling him to come quickly.  He also confirmed that the boy said that the fire was occurring at night despite the fact that it was late afternoon.  He also stated that the actual fire occurred the next day while his son was fast asleep in bed.

This case is of interest in view of the large number of corroborating witnesses.  As noted above, however, the memories of at least some of these witnesses appear to have become somewhat distorted over time.

The boy’s father stated that he had heard that the fire had been investigated as a possible arson.  Thus, there is the possibility that the boy had subconsciously picked up cues from the arsonists’ activities, which were then manifested as a vision.  Such possibilities aside, this case is suggestive of a precognitive hallucination.  This is somewhat unusual in that most ostensible psi experiences taking place in the waking state involve contemporaneous events, whereas dreams are much more likely to be precognitive.   

 The following is an apparent case of hallucinatory ESP taken from the early investigations of the Society for Psychical Research (SPR), an organization of prominent scientists and scholars founded in England in 1882 to study such anomalous events and which is still in existence today:

On Thursday evening, 14th November, 1867, I was sitting in the Birmingham Town Hall with my husband at a concert, when there came over me the icy chill which usually accompanies these occurrences. Almost immediately, I saw with perfect distinctness, between myself and the orchestra, my uncle, Mr. W., lying in bed with an appealing look on his face, like one dying. I had not heard of him for several months, and had no reason to think he was ill. The appearance was not transparent or filmy, but perfectly solid-looking; and yet I could somehow see the orchestra, not through, but behind it. I did not try turning my eyes to see whether the figure moved with them, but looked at it with a fascinated expression that made my husband ask if I was ill. I asked him not to speak with me for a minute or two; the vision gradually disappeared, and I told my husband, after the concert was over, what I had seen. A letter came shortly after telling of my uncle’s death. He died at exactly the time when I saw the vision (Gurney, Myers & Podmore, 1886a, p. 194).

Another case involving a visual hallucination was provided to the Society by a Mrs. Bettany:

I was walking along in a country lane at A, the place where my parents then resided. I was reading geometry as I walked along … when in a moment I saw a bedroom known as the White Room in my home, and upon the floor lay my mother, to all appearance dead. The vision must have remained some minutes, during which time my real surroundings appeared to pale and die out; but as the vision faded, actual surroundings came back, at first dimly, and then clearly.  I could not doubt that what I had seen was real, so instead of going home, I went at once to the house of our medical man and found him at home.  He at once set out with me for my home, on the way putting questions I could not answer, as my mother was to all appearance well when I left home. I led the doctor straight to the White Room, where we found my mother actually lying as in my vision. This was true even to minute details. She had been seized suddenly by an attack of the heart, and would soon have breathed her last but for the doctor’s timely advent. I shall get my mother and father to read and sign this. (Gurney, Myers & Podmore, 1886a, p. 194.)

In response to questioning, Mrs. Bettany stated that she was not feeling anxious about her mother at the time of her death. She also noted that she had found a handkerchief with a lace border beside her mother on the floor, a detail which corresponded to her vision. Her father, upon being interviewed, corroborated his daughter’s statement and added that, so far as he was able to tell, his wife was taken ill after his daughter had left the house.  Of course, in this case a determined skeptic could argue that the daughter might have subconsciously noticed subtle signs of cardiopulmonary distress before the full-blown heart attack occurred. Such a phenomenon is known as “sensory cueing” and will be discussed in more detail below.

As noted above, hallucinatory experiences frequently involve senses other than vision.  However, vision is the most frequent modality among seemingly psi-induced hallucinations, whereas the hallucinations of psychotics most frequently involve the auditory modality.  A typical auditory hallucination suggestive of the operation of psi might consist of hearing your mother’s voice calling you at the exact time that she is experiencing some sort of physical crisis at a distant location.  Smell, kinesthesia (muscle sense), pain and other sensory modalities may also be involved.  The Finnish folklorist Leea Virtanen (1990) notes that cases involving the parallel experiencing of physical symptoms of disease and injury are quite common and most often occur between parent and child.  The following is such a case taken from the early investigations of the SPR:

I woke up with a start, feeling I had had a hard blow on my mouth, and with a distinct sense that I had been cut and was bleeding under my upper lip, and seized my pocket-handkerchief and held it (in a little pushed lump) to the part, as I sat up in bed, and after a few seconds, when I removed it, I was astonished to not to see any blood, and only realized it was impossible anything could have struck me there, as I lay fast asleep in my bed, and so I thought it was only a dream! - but I looked at my watch, and saw it was seven, and finding Arthur (my husband) was not in the room, I concluded (rightly) that he must have gone out on the lake for any early sail, as it was so fine.  

I then fell asleep.  At breakfast (half-past nine) Arthur came in rather late, and I noticed he rather purposely sat further away from me than usual, and every now and then put his pocket handkerchief furtively up to his lip, in the very way I had done.  I said “Arthur, why are you doing that?” and added a little anxiously “I know you have hurt yourself! But I will tell you why afterwards.”  He said, “Well, when I was sailing, a sudden squall came, throwing the tiller suddenly around, and it struck me a bad blow in the mouth, under the upper lip, and it has been bleeding a good deal and won’t stop.”  I then said, “Have you any idea what o’clock it was when it happened?” and he answered, “It must have been about seven.”

I then told what happened to me, much to his surprise, and all who were here at breakfast.

I happened here about three years ago at Brantwood to me. (Gurney, Myers, & Podmore, 1886a, pp. 187-189.)

This woman’s story was corroborated in a statement made by her husband.

A very similar case was provided to me by one of my students.  According to the student, his father was suddenly knocked off the bench he was sitting on by an invisible blow to the jaw.  A few minutes later, he received a call from the health club where his wife was working out informing him that his wife had just broken her jaw on a piece of gymnastic equipment.  One skeptical explanation of psi experiences is that they are the product of coincidence.  For instance, women may frequently dream of their husbands’ deaths, so one would expect that some of these dreams may occur at or shortly before the husband’s death.  In the case of my student’s father, such an explanation is much less plausible, as the baseline probability of the event is virtually zero.  It would be absurd to argue that men are frequently knocked off benches by invisible blows and that some of these blows are likely to coincidence with an injury to a family member by chance.

Intuitive Experiences  

The second major category of experiences that are suggestive of the operation of ESP is that of intuitive experiences.  Intuitive experiences typically occur in the waking state and most often involve a feeling that something is wrong at a distant location that is later corroborated.  The following intuitive experience is taken from Stevenson (1970b).

Around the middle of June, 1964, Linda and I decided to visit the Travis’ [sic] to congratulate them on their new child.  After supper we put the children to bed and we asked Linda’s grandmother to babysit for a while.

We arrived there and Paul Travis fixed our drinks.  As he was showing me the blueprints of his new house I stopped and had a feeling as if something bad had happened at home, the nature of which I was not aware.

I asked Linda to call home.  She said: “I will in a few minutes.”  I said: “You’d better call now.  Something is wrong.”

Linda went into the bedroom where the phone was and I followed and my feelings were then of distress.  Our…neighbor answered the phone.  Both children were screaming in the background.  She informed us that Linda’s grandmother had hurt her back just a few minutes earlier and [that] the children were so frightened…

We arrived home and the neighbor met us at the door, saying that Linda’s grandmother had called upon her after she hurt her back.

Scott, my son, was frantic and refused to go to Linda and clutched me for comfort.

What is surprising about this incident is the sudden feeling of distress and my insistence on Linda to call home and my premonition that something bad [had] happened.  (Stevenson, 1970b, pp. 49-50.)

This statement was corroborated by the informant’s wife, who added that the informant had never previously displayed strong anxiety about something being wrong at home and had never previously asked her to telephone a babysitter while they were away.


The third major mode of psi experience is that of dreams.  In her classification system, Louisa Rhine divided such cases into those involving realistic dreams, which correspond closely in detail to the confirming event, and unrealistic dreams, which she defined as containing “a bit of imagination, fantasy and even symbolism” (Rhine, 1977, p.71).  As an example of symbolism, she offered the case of a woman who dreamed of heavy black smoke prior to tragic events.  Virtanen (1990) in her study of spontaneous psi experiences used a category that she called “symbolic dreams,” which is analogous to Louisa Rhine’s unrealistic dream category.  As examples of symbolic dreams depicting death, Virtanen cites dreams of a person going on a journey, ascending to heaven, departing toward black trees, swimming in black ice, and well as the snuffing out of a candle and a black butterfly flying by.  About one-third of Virtanen’s dream experiences fell into this category.

The following account, taken from Louisa Rhine’s collection, is an example of a realistic dream.  It was provided to Rhine by the district manager of a sheet and tin plate company. The experience occurred shortly before he and several business associates were to return home from a two-week vacation in the wilderness, where they had been cut off from all news sources.

The night before they were to return home, the district manager had a dream, so clear, so vivid, he could not sleep afterward. In it, he writes, “one of our locomotive cranes that was unloading a car of scrap iron, together with the car, was on the track near the bank of a river alongside the water tower which served the locomotives. For some unaccountable reason, as the huge magnet swung around with a heavy load of scrap, it suddenly toppled over the river bank. The operator, whom I called by name, jumped clear of the crane and landed below it as it came bounding, tumbling and bouncing down the river bank, and he finally disappeared from view as the crane came to rest twenty feet below at the water’s edge. I particularly noted the number of the crane and the number and positions of the railroad cars, and was able to tell how the crane operator was dressed. Furthermore, I noticed the approximate damage done to the crane. I did not know, however, what had finally happened to the operator. He had disappeared under or behind the crane after it had come to rest. In other words, I was observing the accident from somewhere in or across the river.

“Upon my return to the mill the following day, the first man I met was the master mechanic. He told me to come with him to inspect the crane of my dream, to talk with the operator who had emerged from the accident without a scratch. The operator explained his lack of injury by the fact that the crane had fallen over in front of him as he made his last jump and as it made its last bounce. The record showed the smallest detail to be as I had dreamed it, with one exception. The exception was that the accident had happened two hours after the dream”  (Rhine, 1961, pp. 43-44).

Among Rhine’s examples of symbolic dreams is a case in which a woman had a series of dreams in each of which the symbol of an avenue of trees seemed to be used to dramatize an impending death (Rhine, 1961, pp. 49-50). The first such dream occurred when the woman was a 12-year-old girl.  She had fallen asleep in a swing in the yard of her house and dreamed that she had seen her mother walking down a beautiful avenue of trees.  She ran after her, realized that she was not going to be able to catch up to her and then called out to her.  She turned, put up her hand and said, “Go back my daughter, your father needs you.” 

When she woke up, she immediately went into the house.  Her father greeted her, embraced her and informed her that her mother had just died.

About 12 years after the first dream, the second dream occurred.  Her brother was ill in a hospital in another state. She was herself ill and could not be with him.  The night he died, she dreamed that he too was walking down the same avenue of trees.  She tried to catch up to him but he told her to go back. (As we will see later, these dreams bear some resemblance to near-death experiences, in which the experiencing parties are told that it is not yet time for them to die and that they must return to life.)  As it turned out, her brother died at the approximate time of the dream.

In the third dream, she saw her husband quickly walking down the same avenue of trees. He too put up his hand and said, “Our precious children need you—go back.” The dream frightened her and she put her arms around her husband awakening him. He announced that he was feeling very sick, and he died a few minutes later.

Of course, the astute skeptic might note that in each of the above dreams, the woman might have had some reason to expect that the person’s death was imminent.  In the last case, she may have subliminally heard sounds of her husband’s physical distress as she slept.  Such objections would be more difficult to raise in the case of the fourth dream, in which the woman dreamed that her daughter and her girlfriend, who had gone to a dance, were involved in a fatal accident in front of her home.  The same avenue of trees came into play in the dream.  Needless to say, the woman was quite relieved when the girls returned safely home from the dance around 1:00 A.M.  The very next night, her daughters had a dance in their house. The girlfriend of her daughter that had appeared in the dream was in fact killed within a block of her house as she was on her way home. The woman noted that the accident was “just as I had dreamed it.”

It is of course possible that the woman had observed that the girlfriend was a reckless driver; Rhine’s account provides us with no information on this point.

The psychiatrist Berthold Schwarz provides the following case, which incorporates both realistic and symbolic elements.

Bartholomew A. Ruggieri, M.D., my friend and hardworking neighbor pediatrician, wrote this memo: “On the afternoon of Sunday, June 2, 1968, I went up to my room to nap. I slept fitfully, from about 2:30 P.M. to 5–5:30 P.M. During this time I dreamed that I was at an upper story window facing Avenue B and Sixth Street in New York City, and saw a ‘parade’ of mourners approaching as pictured [diagram drawn by Dr. R]. It was more a mass of mourners than a parade. They carried a banner with a religious connotation and ending with the words: ‘…KENNEDY ASSASSINATION.’ I know the area very well, having lived my youth there, but to my knowledge I have never lived on Avenue B.  I awoke, vividly recalling all the words on the banner, felt I should get up and write them down, but did not do so.  I lay in bed and, after a period of drowsiness, again fell asleep.  Somehow in my mind I associated this to the imminent assassination of Robert Kennedy (Bobby).  The Avenue B would support this.  The same evening (6/2/68) sitting at my desk at 9:30 P.M., I phoned Dr. B. E. Schwarz, described the dream, and said I felt Bobby Kennedy would be assassinated on the 6th of June. Note ‘Sixth’ Street: June is the sixth month” (Schwarz, 1980, pp. 247-248).

While it is true that Robert Kennedy was shot on June 5, 1968, he died on the sixth.  Dr. Schwarz told his wife of Dr. Ruggieri’s dream on the evening of June 2, 1968.

Virtanen (1990) provides a few examples of a novel form of dream telepathy, in which the confirming event is the dream of a second person.  She calls such cases “shared dreams.”  As one example of a shared dream, she cites a case in which a man was awakened by a dream in which he hit his son on the head with a stick.  The son woke up crying and said, “Father hit me on the head with a stick” (p. 99).

Van de Castle (1994) has also related several examples of shared dreams.  A few involved some of his own dreams during a night when he was serving as the “sender” in one of the experiments on telepathic dreaming conducted at the Maimonides Dream Laboratory in Brooklyn New York.  One of Van de Castle’s dreams involved a barking dog.  The “receiver” in the experiment also had a dream with a dog in it.  In another of Van de Castle’s dreams, his wife took a car trip and encountered a man with whom she talked about music. The “receiver” in the experiment dreamed that she was on a car trip with other people and was later talking with one of the same people involved in the car trip of Van de Castle’s dream.  Van de Castle cites work by Rechtschaffen (1970) indicating an unusual degree of correspondence between the dreams of subjects sleeping at the same time in a sleep laboratory.  In one case, a subject dreamed about singing in Russian, while another subject dreamed about students doing some kind of interpretive singing.  In a second instance, the first subject dreamed about taking a violin lesson while the second was dreaming about learning a guitar melody.  In a third instance, both subjects dreamed about watching gangster movies.  A skeptic might conjecture that, if the subjects in the sleep lab were friends, it is possible that similar interests (e.g., in music or violent movies) and experiences may result in similar themes appearing in the dreams.

One case cited by Van de Castle, taken from Green (1968), involved lucid dreams (dreams in which the dreamer is aware that he or she is dreaming).  In this case, both a mother and her son experienced lucid dreams on the same night.  The mother felt that she had contacted her son and had spoken a sentence to him in her dream, which the son repeated back to her when they met for lunch the following day.

Psi-mediated Instrumental Response 

Stanford (1974, 1990a) has pointed to one possible type of psi experience that may be missed in Louisa Rhine’s classification scheme. This category encompasses cases in which a person takes an action that is appropriate to a situation when the person has no normally acquired knowledge (or any conscious paranormally-acquired knowledge) that the situation even exists. Presumably, in such cases the person is acting on the basis of information provided by ESP at an unconscious level.  Stanford uses the term “psi-mediated instrumental response,” or PMIR, to describe such events.  As an example, he cites the case of a retired New York attorney who was traveling to Greenwich Village to drop in on two artist friends.  He had to change subway trains, and upon leaving the first train, he claimed that he “absent-mindedly” walked out through the gate and was halfway up the stairs to the street before he realized that he had intended to switch trains.  Not wishing to pay another fare, he decided to walk the additional six blocks south. He then ran into his friends, who had left their home and were walking north along the same route on their way to an appointment.  

One reason why examples of PMIR may be relatively rare in collections of spontaneous cases may be that the people involved in such cases do not typically have any awareness of possessing paranormally-acquired knowledge and are consequently likely to attribute their experiences to luck or coincidence rather than to the operation of ESP or PK (psychokinesis).  Stanford suggests that cases of PMIR may be occurring frequently without the people involved being aware that anything unusual is going on.

Physical Effects

Louisa Rhine’s second major category of paranormal experiences involves puzzling physical effects, such as the stopping of a clock at the time of the owner’s death or a person’s portrait falling off a wall at or near the time of the person’s death. One of her cases involved a man in Wisconsin who died in an easy chair in his living room. The watch in his vest pocket and the large clock in the living were both found to have stopped, each at the approximate time of the man’s death (Rhine, 1961, p. 243).

Sometimes the timepieces involved are at a considerable distance from the dying person, as in the following case:

A woman in New Hampshire reported that when she was a girl of about 12 she came home from school one day and her mother told her about a queer occurrence.

Her mother said she was sitting knitting in the kitchen about 2 o’clock that afternoon when the clock stopped for no apparent reason.  It was not run down for it soon started running again and kept going until evening, the time that it usually was wound.

Three days later a cable came from overseas saying that her mother’s sister had died.  It was the day and hour the clock stopped.  (Rhine, 1981, p. 196).

Not all of Rhine’s clock cases involved the stopping of timepieces. Occasionally, timepieces were reported to have behaved aberrantly at the time of a death. One woman gave an account of a case in which a clock that normally chimed only on the hour chimed once at 7:20 P.M., surprising the woman and her parents. Five minutes later, they received a phone call informing them that their mother’s sister had died of a heart attack at 7:20. This was the only occasion on which the clock chimed at a time other than on the hour (Rhine,1961, p. 244).  

Ian Wilson describes a similar case involving the late Pope Paul VI. At the time of the Pope’s death (9:40 P.M. on August 6, 1978), his bedroom alarm clock, which had always been set to 6:30 A.M., inexplicably rang (Wilson, 1987, p. 183).  However, Mary Roach (2005), in a detailed investigation of several famous cases suggestive of survival after death, interviewed several witnesses in connection with this case.  In the course of those interviews, Archbishop Pasquale Macchi, one the pope’s associates, stated that on the morning of the Pope’s death, he had rewound the pope’s clock, as it was stopped, and likely inadvertently set the alarm time to correspond with the pope’s death.  Of course, even if this explains the anomalous ringing of the alarm, the fact that it was accidentally set to the moment of the pope’s death could be another instance of Stanford’s PMIR.    

Objects are occasionally reported to fall or break at the time of a significant crisis to a person associated with the object, as in the following case from Louisa Rhine’s collection:

A woman in Nevada tells of an experience which centered on her elder brother Frank. He was an especially thoughtful boy who did many things to please his mother, to whom he was very close. She says: “One day he came home with a beautiful cut-glass dish. Mom thought it was just about the most wonderful thing that ever happened to her and put it on our sideboard.

“When the rest of us had chicken pox, my brother Frank was sent down to my grandmother’s in Grand Haven, Michigan, which was about forty miles from where we lived, although Mother was reluctant to have him go. Two days after Frank left, Mom and our neighbor were having their morning coffee and talking, and we children were told to be quiet. All of a sudden, this cut-glass dish that Frank had given Mother popped and broke right in two. It was just sitting on the sideboard. Mother screamed and said, ‘My God! Frank has just been killed.’ Everyone tried to quiet Mother, but she said she just knew.

“About an hour after, or a little more, we received a telegram from Grandpa which said to come right away, something had happened to Frank. Mom said, ‘I know.’ She cried all the way going to Grand Haven, and Grandpa met us at the train. Before Grandpa could tell us what happened, Mom cried, ‘At what funeral parlor is he?’ Grandpa just stood there with his mouth open and Mom ran right up the street and went to the place Frank was without being told. They wouldn’t let her see him because a terrible thing had happened.

“The boy next door to Grandfather was home from school and his parents were not at home, so he started playing with his father’s shotgun, and came outside, showing it to Frank. The boy, not knowing it was loaded, pulled the trigger and killed my brother. The strange thing—Frank was shot at the same time the dish broke.” (Rhine, 1961, pp. 245-246).

Cases involving physical effects are relatively rare. Rhine (1963) noted that her case collection at that point contained only 178 physical effect cases, in comparison to over 10,000 ESP cases.  Of those 178 cases, 65 involved falling objects, 49 involved the stopping or erratic movement of timepieces, 21 involved breaking or exploding objects, 17 involved lights turning on and off by themselves, 14 involved the sudden opening or closing of doors and 12 involved rocking and moving objects (half of which were rocking chairs). In 37 of the 49 clock cases, the clocks stopped at the time of death of a person associated with the clock.  In 18 of the 65 cases involving falling objects, the object in question was a picture or portrait of a person undergoing a crisis, such as a serious accident or death, at the time of the object’s movement.  Thirteen other such objects bore a special relationship to a person undergoing a crisis at the time of the event.

Sometimes it is difficult to know whether a physical effect or an hallucination is involved.  For instance, perceived raps or voices could simply be auditory hallucinations.  On the other hand, they might be caused by real physical sound waves.  One way to decide which is the case would be to see if such sounds can be collectively perceived (that is, can be heard by more than one person).  In an attempt to resolve this issue, Louisa Rhine (1981) examined instances in which more than one person was present when the sound was heard.  In 68 such cases involving vocal sounds, the sounds were heard by a second person only 28 percent of the time, whereas mechanical sounds, such as raps, were collectively perceived in 93 percent of the 63 cases involved.   In her study of Finnish cases, Virtanen (1990) also found voice sounds to be collectively perceived less frequently than “noisy” sounds such as bumps, thuds and rattles, as did Rinaldi and Piccinni (1982) in their door-to-door survey of cases in the South Tyrol section of Italy.  Taken together, these data suggest that cases involving mechanical or “noisy” sounds involve real physical effects more often than do cases involving vocal sounds (which are more likely to be hallucinations).

A similar controversy surrounds cases in which someone experiences the apparition of a person near the time that the person was dying or experiencing a serious crisis at a location distant from the observer.  In a case unearthed by the early investigators of the Society for Psychical Research, a man who was staying in Paris, and was consequently separated from his five-year-old son in London, was awakened by the sound of his son’s voice at 7:30 A.M.  He then saw a bright, opaque white mass before his eyes, and in the center of the light he saw the smiling face of his son. He later learned that his son had died at the exact time of the apparition  (Gurney, Myers & Podmore, 1886a, p. 144).

In this case the child’s apparition could be interpreted as a telepathically induced hallucination or some sort of ghost existing in physical space. If several observers are present when an apparition appears and only one of them sees it, it would seem reasonable to assume that the apparition was an hallucination. On the other hand, if several of the witnesses simultaneously see the apparition, it would seem more reasonable to assume that some sort of physical ghost had put in an appearance.  To see which was the case, G. N. M. Tyrrell (1953), a prominent authority on ghosts and apparitions, looked at 1,087 apparitional cases collected by the researchers of the Society for Psychical Research (Sidgwick et al.,1894).  He found that in 283 of those cases more than one person was present at the time the apparition was seen.  In 95 of these 283 cases, more than one person saw the apparition.  In a later study, Hornell Hart (1956) found 46 cases in the literature satisfying the more restrictive criterion that the secondary witnesses present were clearly situated in such a manner that they would have been able to see the apparition had it been a physical object.  In 26 of those cases, the apparition was seen by at least two observers.  In a more recent survey of apparitional experiences conducted through the mail, the Icelandic parapsychologist Erlendur Haraldsson (1991) found that a second potential observer was present in about half of the apparitional encounters reported. In about one-fourth of these cases, the respondent stated that the apparitional experience was shared by such secondary observers.  Thus, it is difficult to tell on the basis of collective perception whether such experiences involve mere hallucinations or physical ghosts. 

The physical ghost theory was favored by the early psychical researcher Frederic W. H. Myers (1903), who called his ghosts “metetherial presences.”  Myers’ contemporary Edmund Gurney believed that cases in which apparitions were sighted by more than one person could be explained by assuming that hallucinations could spread telepathically from one mind to another (Gurney, Myers & Podmore, 1886a, 1886b).  Myers argued against Gurney’s theory that hallucinations can spread telepathically on the basis of the fact that the hallucinations of the insane are not in general particularly contagious.  Other theorists, including Tyrrell and the philosopher H. H. Price (Tyrrell, 1953; Price 1939, 1940, 1948, 1953, 1959, 1961), speculated that witnesses to apparitional cases share a deep region of the unconscious mind that may be termed the “collective unconscious” and that it is in this deep region of the mind that the apparitional image is constructed (which then emerges from the collective unconscious into the individual consciousness of the witnesses).  Finally, the American parapsychologist Karlis Osis (1981) suggested that we call it a draw and assume that some apparitions are ghosts and others are hallucinations.

Research Findings Relating to Spontaneous Cases

Incidence Rates

A large number of surveys have been conducted in an attempt to determine how many people have had experiences suggestive of ESP or PK. The results of these surveys, taken together, suggest that somewhere between one-third and one-half of the population claims to have had some sort of psi experience, and that this proportion seems to be fairly independent of culture and nationality.

Dreams appear to be the most common type of ESP experience, with intuitive experiences being the next most common and hallucinatory experiences the least common form.  For instance, in one statistical analysis of her own collection reported by Louisa Rhine (1962a), 65 percent of the experiences were dreams, roughly a quarter were intuitive experiences and the remaining 10 percent were of the hallucinatory variety.  One finding that is fairly consistent across case studies is that dreams tend to be precognitive (that is to involve the apparent paranormal perception of future events), whereas waking experiences (including intuitive and hallucinatory cases) seem more often to refer to contemporaneous events (Rhine, 1981; Schouten ,1982).

In terms of incidence rates in the general population, in a survey involving interviews with 1100 German citizens, Schmeid-Knittel and Schetsche (2005) found that 49.5% of the survey participants reported having experienced the sensation of déjà vu (discussed in more detail later in the chapter), 36.7% reported having dreams involving ESP, 18.7% reported experiencing crisis-related ESP, 15.8% reported apparitional experiences, 15.3% reported experiences involving ostensible psi on the part of animals, and 12.1% reported having experienced phenomena suggestive of hauntings. 

Dream experiences usually contain more detail and more complete information about the event than do intuitive experiences, whereas intuitive experiences tend to produce a greater sense of conviction that the experience refers to a real event and is more likely to lead the percipient to take some sort of action related to the event (see Schouten, 1979, 1981, 1982; and Rhine, 1978, 1981). 

A great many more women report having ESP experiences than do men. Whether this is due to enhanced sensitivity or psychic powers on the part of women or is due to a lesser reluctance on the part of women to report such experiences is not clear.  As might be expected, spontaneous cases typically involve the anomalous knowledge of events happening to members of the percipient’s immediate family rather than events happening to strangers or casual acquaintances.  In general, the events that are perceived through ESP are negative ones involving death or serious injury to a close family member. Hardly ever does the experience relate to damage to material objects rather than to people (see Schouten, 1979, 1981, 1982). 

Link to Geomagnetic Activity

Several researchers have reported links between the activity of the Earth’s magnetic field and the incidence rate of spontaneous psi cases.  Foremost among these investigators is the Canadian psychologist Michael Persinger, who has authored a series of papers on the subject (Persinger, 1985, 1986, 1987; 1988; Persinger & Krippner 1987, 1989; Persinger & Schaut, 1987).  In analyzing several case collections, Persinger has found global geomagnetic activity typically to be lower on the days of reported ESP experiences than on the days surrounding the day of the experience. This finding applies chiefly to cases in which the alleged psychic experience was nearly simultaneous with the confirming event.  It does not hold in cases of apparent precognition nor does it hold for apparitional experiences that occur some days after the perceived person’s death. 

Persinger proposes two theories to account for apparent cases of spontaneous ESP (Persinger, 1988; and Persinger & Krippner, 1989).  The first theory involves a direct signal transmitting information between the two parties involved in an apparent case of telepathy.  In the second theory, it is assumed that some external factor causes the two people to have similar experiences.  For instance, it might be possible that low barometric pressure could cause the “percipient” in an apparent case of spontaneous telepathy to be in a gloomy mood and also to cause one of the percipient’s closest friends, who is a chronic depressive, to commit suicide by driving her car off a cliff.  The percipient might then interpret his apparent gloom as being due to a paranormal awareness of his friend’s death.  Persinger’s second theory is thus a theory of pseudo–ESP phenomena rather than of true ESP in that it denies the existence of an anomalous channel of information transmission.  It is obviously conceivable that geomagnetic activity may have similar effects on the mood or behavior of two related persons and thus may generate a case of pseudotelepathy as suggested by Persinger’s second theory.

With regard to the first theory, Persinger conjectures that geomagnetic activity may enhance the receptivity of the brain to extrasensory signals, noting in particular that sudden decreases in geomagnetic activity may decrease the likelihood of certain types of electrical seizures in the brain.  Persinger contends that increases in geomagnetic activity tend to lower seizure thresholds and may even precipitate convulsions in epileptics. Some scientists (e.g., Radin, McAlpine & Cunningham, 1994; and Adair, 1991) have, however, expressed skepticism that changes in the geomagnetic field would have sufficient strength to produce any physiological effects on the human body at all.  

As a second possibility, Persinger suggests that lowered geomagnetic activity might enhance the signal carrying the ESP message, which he has speculated may consist in part of extremely low frequency electromagnetic radiation.

Psychological Processes

Many parapsychologists have proposed that extrasensory perception is a two-stage process from a psychological point of view.  Both G. N. M. Tyrrell (1946) and Louisa Rhine (1978, 1981) proposed that the information obtained through ESP is first received at an unconscious level of the mind and then emerges into consciousness in the form of an hallucination, dream or intuitive feeling that something is wrong. Rhine suggested that emotional reactions, impulses toward action, and feelings of conviction about the reality of the sensed situation may emerge into consciousness independently of the factual information relating to the sensed event, especially in intuitive cases. K. Ramakrishna Rao, J. B. Rhine’s successor as Director of the Institute for Parapsychology in Durham, North Carolina, observed that minor details may have more difficulty penetrating the barrier between the unconscious and conscious regions of the mind than more emotionally important elements might have. He indicates that this may be a reason for the failure of many experiments in the laboratory that require subjects to guess the identity of emotionally trivial targets such as ESP cards (Rao, 1986).  His views in this regard are similar to those of the psychoanalyst Jan Ehrenwald (1977, 1978), who postulated that the weakness of ESP effects in the laboratory may be due to the fact that the ESP message is typically much less relevant to the needs of the subject in laboratory experiments than it is in spontaneously occurring cases of extrasensory perception. Thus, Ehrenwald suggested, laboratory cases of extrasensory perception depend for their success on flaws in the “filter” that the French philosopher Henri Bergson (1914) proposed existed to screen out noncrucial information so that the conscious mind could focus on immediate problems relevant to the biological survival of the body. 

Sigmund Freud, the founder of psychoanalysis, proposed a model of telepathy similar to Tyrrell’s and Rhine’s.  Freud had a lifelong interest in parapsychology, or psychical research as it was called at the time.  He was a member of both the American and British Societies for Psychical Research, and in 1921 he went so far as to write the American psychical researcher Hereward Carrington that, if he were at the stage of embarking on a career rather than ending one, he would perhaps choose psychical research!  The psychiatrist E. Fuller Torrey (1992) reports that Freud even claimed to have had telepathic contact with his fiancée Martha Bernays.  Many of his thoughts on telepathy were, however, suppressed from publication during his lifetime under the influence of his disciple Ernest Jones for fear of undermining the credibility of the psychoanalytic movement.

Freud assumed that, if telepathy existed, the same dynamic processes would govern the emergence of psi information into consciousness as governed the emergence of other unconscious material.  As an example, Freud (1963) reported the case of a man who dreamed that his wife gave birth to twins at the same time that his daughter gave birth to twins in real life. Predictably enough, Freud attributed the distortion of the telepathic message to the man’s unconscious wish that his daughter be his wife.

The Australian psychologist Harvey J. Irwin likewise feels that repression may prevent ESP messages from emerging into consciousness.  As a possible example of such suppression, he cites a case of Louisa Rhine’s in which a woman began to sob uncontrollably for 20 minutes before a huge decorative vase fell off its shelf. Later she learned that her father had died about that time. Presumably, as her conscious mind blocked out the ESP signal, her unconscious mind was forced to move the vase psychokinetically in order to dramatize the message and get it through to consciousness (Irwin, 1989). 

Skeptical Explanations of Spontaneous Cases

Critics of spontaneous case investigations are quick to point out that there are many explanations besides ESP and psychokinesis that might account for apparent cases of paranormal phenomena. First, the cases may be due to coincidence. For instance, consider a case in which a man is overcome by a sense of impending doom, breaks out in a cold sweat and refuses to board an airplane, and then later learns that the plane crashed upon landing at its destination. It might be quite plausible to assume that many people back out of imminent airplane flights because of sudden feelings of nervousness and anxiety. Occasionally, the planes involved in some of these flights may crash, thus producing what looks like a spontaneous case of intuitive ESP when really all that is involved is simple coincidence. Similarly, people may frequently dream of the death of one of their parents. When such a dream happens by chance to fall on the night preceding the parent’s actual death, another spurious precognition case is generated.

Richard Broughton (1991), a former Director of the Rhine Research Center in Durham, has noted that explanations in terms of coincidence are not particularly plausible when applied to experiences involving hallucinations or psychosomatic pain.  For instance, recall the case of my student’s father who was knocked off a bench by an “invisible blow to the jaw” at the time that his wife broke her jaw on a piece of gymnastic equipment.  Surely, it would be absurd to argue with regard to such a case that men are constantly being knocked off benches by invisible blows to the jaw and that sooner or later one of these events is bound to occur simultaneously with the breaking of the jaw of a member of the man’s immediate family.

Despite the implausibility of coincidence explanations in hallucination cases, the early investigators of the Society for Psychical Research attempted to perform a statistical analysis to rule out the coincidence hypothesis in the case of crisis apparitions. They conducted what they called a “Census of Hallucinations” in order to find out how often people experienced apparitions of human figures. (Sidgwick et al., 1894).  They found that, of the apparitions reported to them, one in 63 occurred within 12 hours of the death of the person whose apparition was experienced. Based on existing death rates, the investigating committee concluded that only 1 in 19,000 such hallucinations would occur so close to the death of the appearing figure by chance.  One could certainly quibble with this analysis. For instance, it could readily be imagined that cases in which a person’s apparition was experienced in close proximity to the time of his death would make a deep impression on a person and might therefore be more easily remembered than other hallucinations of human figures, thus artificially inflating the proportion in the sample.

A second, more informal statistical argument is provided by the Italian investigators Rinaldi and Piccinini (1982), who conducted a door-to-door survey related to psychic experiences in the South Tyrol region of Italy. By interviewing informants about deaths in the family, they found that one in twelve deaths were accompanied by a paranormal experience related to the death.  When only sudden deaths were considered, one in six deaths were the target event in a reported psi experience.  It strains one’s credulity, they argue, to assume that such a high proportion can be accounted for by chance coincidence.

A special form of the coincidence explanation is what the Dutch parapsychologist Sybo Schouten calls the “worry” hypothesis.  Schouten (1979, 1984) observes that the large number of psychic experiences that involve death or injury to members of the percipient’s immediate family might be due to a combination of coincidence and the tendency of persons to think and worry about close family members.  In a survey aimed at examining this hypothesis, Schouten found people’s predominant worries to be about daily matters, material things, their present psychological situation and events happening to themselves rather than the traumatic events to others that are frequently the subject matter in spontaneous cases of ESP.

In general, any attempt to assess the actual probability that the evidence from spontaneous cases is due to chance coincidence, whether performed by the proponent of psi phenomena or the skeptic, is fraught with pitfalls.  Such calculations rely on too many debatable and hidden assumptions, and the data are subject to too many distorting factors to allow any definitive assessment to be made. This is one of the reasons why parapsychologists have largely turned from the study of spontaneous cases to the study of psi processes in experimental situations, in which the probability that the results are due to chance can be more or less precisely calculated.

A second problem pointed out by critics of spontaneous case investigations is that what appears to be anomalously acquired knowledge may in fact represent information that has been consciously or unconsciously acquired through the normal sensory channels or may be based on unconscious inference from such information. For instance, a woman’s husband may be exhibiting a depressed mood, increasingly reckless driving, and a decidedly morbid interest in automobile accidents on the evening news while polishing off his final two six packs of beer.  She may then unconsciously infer that he is becoming suicidal or at least dangerously alcoholic, and her unconscious mind may present this conclusion to her in the form of a dream in which her husband is involved in a fatal car accident.  If her inference is accurate and her husband is subsequently killed when his car collides with a pickup truck, an apparent case of spontaneous psi, which is really due to unconscious inference, is generated. Similarly, a trapeze artist may subliminally perceive a frayed wire and consequently have an apparently premonitory dream of her partner’s fall to his death. I myself once had a dream that my wife had run out of gas in her car. About two hours after the dream, she called me up to tell me that she had run out of gas on her way to work. The gas gauge on her car was broken at the time, so it is quite possible that I had unconsciously inferred that she was about to run out of gas due to the fact that the gas tank had not been filled in quite some time.

Sometimes no direct signal may be involved in an apparent case of ESP, but rather a third factor may cause both the percipient’s mood and the target event.  For instance, the parapsychologist Ed Cox, famous for his invention of innumerable Rube Goldberg–like devices for testing for psychokinesis, found that trains involved in accidents tend to carry significantly fewer passengers than comparable trains not involved in accidents (Cox, 1956).  Cox interpreted this finding as evidence that people use their precognitive powers (consciously or unconsciously) to avoid being involved in accidents.  Physicist John Taylor (1980) on the other hand points out that a third factor, such as bad weather, may contribute to both the passengers’ decisions not to travel and to the increased probability of an accident.

A third line of criticism of spontaneous case evidence centers around the possibility that the testimony provided by the informant may not be an accurate portrayal of the events as they occurred, due to distortions of memory, delusions, conscious or unconscious embellishment of a case to make it seem more impressive, and possibly even outright fabrication of a case in a conscious effort to perpetrate a hoax.  For instance, in the fictional case considered above, the woman may merely have dreamed of a car accident, but reported that she dreamed of her husband being killed in a collision with a pickup truck because she viewed her dream as a premonition of that event and wished to communicate that fact.  Alternatively, she may have consciously added the details regarding the truck to make the dream more impressive to the researcher, a form of falsification which she may take to be benign.  A third possibility is that her memory of the dream and the actual event may have been confused, so that she came to believe that she saw a pickup truck in the dream when in fact she had not. This process is known as confabulation as (or, more often these days, as “false memory”).  

In some instances, the testimony of independent witnesses can help bolster one’s confidence that the experience occurred as the informant described it.  For instance, a percipient may have related a precognitive dream to her family before news of the confirming event was received.  In such a case, the family members may be interviewed to obtain independent confirmation that the dream in fact occurred.  Such independent testimony would then constitute evidence against the hypothesis that the percipient simply made up the precognitive dream after hearing of the confirming event or that she came to believe falsely that she had had such a dream through a memory distortion process.  It was the practice of the early psychical researchers, who sought to prove the existence of ESP through the analysis of spontaneous cases, to obtain such independent testimony when available, and that is still the practice of a large proportion of case investigators today.  As a result, there are many cases on record in which such independent testimony corroborates the existence of the ostensible psi experience.

Memory distortion can also be minimized if written descriptions of the experience are made as soon as possible. This criterion is met by dream diary studies in which the dreams were immediately recorded, such as those reported by Schriever (1987), Sondow (1988) and de Pablos (1998).  The subject in Schriever’s study sent all her dream reports to a research institute, and Schriever eliminated all reports that did not reach the institute before the confirming event occurred.  This method carries the advantages both of allowing corroboration by witnesses and of immediate recording of the experience.

Schouten (1981) found that the number of details in case reports and the length of such reports fell off as the time interval before reporting the case increased. He attributes this effect to the percipients’ forgetting of details over the course of time.  This finding could be cited as evidence against the hypothesis that spontaneous case informants tend to “improve” their testimony or embellish their reports over time.

Recent research by Elizabeth Loftus and her colleagues has amply demonstrated that false memories may easily be implanted in people’s minds through the use of leading questions and the provision of misleading information (e.g., Loftus, 1995; Lynn, Loftus, Llienfeld & Locke, 2003).  Loftus and her associates have obtained evidence in support of this view from several studies they have conducted (e.g., Hall, McFeaters & Loftus, 1987; Loftus, 1981; Loftus & Greene, 1980; and Loftus, Miller & Burns, 1978). In one such experiment, subjects were lead to believe that they had once been lost in a shopping mall as a child.  In a second study, they found that subjects’ memories could be biased by questions about a stop sign when in fact a yield sign had been presented to them.  In another study, subjects were misled by questions about a nonexistent mustache.  Clearly, psychical researchers must be wary about altering their informants’ testimony and possibly even their memories through the use of leading questions.

A less innocent possibility is that the informant may fabricate the case. Harris (1986) notes for instance that one story, in which British troops were said to have been helped in battle by an apparition of St. George and some accompanying angels, was shown to be a falsification concocted by persons not present at the battle.  In a study of reported premonitions, Hearne (1984) found that his respondents had elevated scores on the Lie-scale of the Eysenck Personality Inventory, which is designed to detect dissembling subjects.  Furthermore, the Lie scores correlated with the alleged accuracy of the reported premonition.  Such findings provide fuel to skeptics wishing to ascribe much of the spontaneous case evidence to fabrication.

Of course some cases of reported psi phenomena are the product of delusion or even outright insanity, as in the case of a schizophrenic man who believes that his garbageman is the reincarnation of Noah and is telepathically commanding him to build a second Ark.  Such cases rarely, if ever, find their way into the serious parapsychological literature. 

Conclusions Regarding Spontaneous Cases

Most parapsychologists today do not feel that the existence of ESP and psychokinesis can be proven on the basis of spontaneous cases, as skeptics can always explain away such cases by ascribing them to coincidence, sensory cues, delusion, memory distortion, and outright falsification.  While the construction of such skeptical explanations for any given case is frequently possible, often such constructions involve so many mental gymnastics that the brusque dismissal of spontaneous case material seems far too cavalier an approach to take.  It is sometimes argued that, while each individual spontaneous case is like a twig that may be broken by counterexplanations in terms of normal processes, when taken as a whole the spontaneous case evidence constitutes an unbreakable bundle of sticks.  Tyrrell (1953) termed this the “faggot” theory, using the word “faggot” in the British sense as denoting a bundle of sticks.  It is true that spontaneous cases follow certain patterns (the events foreseen in precognition cases are predominantly serious health crises to close relatives, for instance) and that they do not resemble the consciously invented ghost stories that appear in the fictional literature.  It could still be maintained, however, that the similarities are simply due to common patterns of human thought and behavior rather than reflecting the characteristics of an anomalous channel of information transmission.   

Louisa Rhine herself initially rejected the position that the existence of psi powers (ESP and psychokinesis) could be established on the basis of spontaneous case evidence.  She maintained that the existence of psi abilities had already been established through the program of experimental research led by her husband, J. B. Rhine. She saw spontaneous cases as being valuable primarily for the insights they might provide into the psi process and particularly for any suggestions they might yield for experimental work.  However, Haight (1979) notes that case investigations and experimental work have become essentially separate approaches to the study of psi, with very little interaction between them.  Rhine herself became less confident in her later years that spontaneous cases would have much of an impact on experimental approaches. She came to see the study of spontaneous cases, not as an enterprise subordinate to experimentation or as justified primarily in terms of its suggestions for experimental work, but as an independent means of investigating paranormal abilities that had value in its own right.  In her words: 

Instead of isolated and concrete suggestions for experiments, the continued study of the [spontaneous] material permitted a more fundamental concept of the psi process than I could have anticipated. (Rhine, 1970, p. 150.)

The brusque dismissal of spontaneous case material by many parapsychologists does a grave disservice to the field. Surely naturalistic observation is of inestimable value in any science. Much remains to be learned from the observation and study of psi phenomena as they occur in their natural setting.

Déjà vu and Psi-trailing

I have held off until now discussing two types of phenomena that do not fall unambiguously into the category of human ESP experiences. These are déjà vu experiences and “psi-trailing” in animals.

Déjà vu

Déjà vu is the fairly familiar experience of having lived through a current situation before.  For instance, a woman may be engaged in a conversation with two friends when a diminutive girl scout cookie salesperson appears at her door. She then gets the eerie sense that this exact sequence of events has happened to her before.  Surveys (e.g., Palmer, 1979; McClenon, 1990) show that the vast majority of people have had such a déjà vu experience.  In a recent review of 50 such surveys, Brown (2004) concludes that approximately two-thirds of the population have had déjà vu experiences.  In their interview survey of the German population, Schmeid-Knittel and Schetsche (2005) found that 49.5% reported déjà vu experiences.  Most individuals report multiple déjà vu experiences.

One explanation of the déjà vu experience would be that one has experienced a very similar situation in the past and that the resultant feeling of familiarity gives one the misleading impression that one has experienced the exact sequence of events before (as opposed to merely a similar sequence).

Efron (1963a, 1963b) proposed a neurological explanation for the sense of déjà vu.  He hypothesized that one hemisphere of the brain may receive information about an event slightly before the other hemisphere does. The second hemisphere will consequently find information regarding the event stored in memory by the time it becomes aware of the event, leading to the conclusion that the event has occurred previously.  However, it takes considerable time for a long-term memory trace to consolidate.  For instance, if you elect to have electrical shock applied to your brain in order to treat a recalcitrant case of severe depression, you may wake up from the treatment to find that your memories for events that occurred in the hours preceding your treatment may be gone.  You may even have spotty amnesia for significant events occurring days, weeks or even years before the treatment.  A similar memory loss may occur following a traumatic head injury.  Neuropsychologists attribute such retrograde amnesia to the disruption of the process by which long-term memories are consolidated in the brain.  Thus, full consolidation of a long-term memory trace may take years; it certainly involves more than the few milliseconds proposed by Efron.  At best Efron can assert that the memory trace is merely the sort of short term trace normally ascribed either to short term memory or the very short term sensory “buffers” proposed by cognitive psychologists. It would seem likely, however, that such a short-term memory trace would be recognized as referring to an immediately recent event, and would not evoke the sense of déjà vu that a long-term memory trace would.

A similar hypothesis has recently been proposed by Brown (2004), who proposes that a neurochemical event may alter the speed of neural impulses in one pathway to the higher sensory centers of the brain, leading to a false sense of recognition when the second bundle of impulses arrive.  Brown notes that a similar theory had been long ago proposed by E. B. Titchener (1928), who thought that déjà vu was caused by a person getting a brief glimpse of an object or situation prior to full conscious perception, resulting in a false sense of familiarity.  Brown also suggests that such experiences may be due to a match between a present situation and an old perception or fantasy.   

A second type of explanation of the experience of déjà vu is that one has in fact experienced the exact situation before, mainly through a precognitive experience such as a dream that has subsequently been forgotten but is still available at a subconscious level.  Louisa Rhine (1961) in fact proposed an explanation of this type.  

Some writers, such as Stevenson (1987) and Fisher (1984) have even proposed that some cases of déjà vu might be explained on the basis of reincarnation.  For instance, a feeling of familiarity on entering a strange city might be due to having lived in that city in a previous life.  Stevenson sees most cases of déjà vu as being susceptible to other kinds of explanations, although he notes that the few instances of déjà vu on record in which a person displays knowledge of a location he has not visited before suggest an explanation in terms of some anomalous process such as precognition or reincarnation. 

It is also possible that such cases might be explained in terms of cryptomnesia, or forgotten knowledge (for instance, a person may have seen a travelogue about the place in question but does not remember having seen it).   In any event, instances in which a person displays detailed anomalous knowledge of a strange or unique site or situation, such as by describing what is around the next corner, go beyond the mere sense of familiarity that constitutes the experience of déjà vu and perhaps should be classed as a probable case of ESP.  The experience of déjà vu itself, which involves only a strange sense of familiarity and not the anomalous possession of knowledge, is probably best not classified as a paranormal phenomenon at all (although it remains possible that such cases may involve forgotten precognitive dreams, as we have seen).


In psi-trailing cases, it is animals rather than humans who display the apparent extrasensory ability.  A typical case of psi-trailing involves a pet getting lost and then apparently making its way to its owner at a distant and unfamiliar location.  J. B. Rhine and his daughter, Sara Feather, compiled a collection of 48 cases of psi-trailing (Rhine & Feather, 1962).  Of these cases, 22 involved dogs, 22 involved cats, and 4 involved birds.  

In one case, a business executive and his family were moving from Tulsa, Oklahoma, to a new home in Memphis, when their pet cat, Smoky, jumped out of the car 18 miles into the journey.  Neighbors reported seeing Smoky two weeks later in the vicinity of the old Tulsa home.  A year later, Smoky reportedly arrived on the front porch of the Memphis home.  The cat was identified on the basis of its physical appearance, including a distinctive tuft of dark red hair under its chin as well as unusual behavioral characteristics, such as the cat’s jumping on the daughter’s right side and putting his paws on the keyboard when she was playing the piano.  In a similar case, a cat was identified on the basis of a deformity in the hip joint.

In yet another case, a dog apparently found its way from Aurora, Illinois, to its owner’s new home in East Lansing, Michigan.  In this instance, the dog was identified on the basis of its physical appearance as well as its distinctive collar.  Rhine and Feather point out that in many cases the identification of the pet cannot be considered definitive.  Also, the majority of their cases (18 of the 22 dog cases, 10 of the 22 cat cases, and 1 of the 4 bird cases) involved fairly short distances (less than 30 miles), raising the possibility that the animal might have been guided by its sense of smell or may have used some other sensory cue to find its owner.


Poltergeist phenomena will be considered separately from the spontaneous cases described above in that poltergeist outbreaks are more rarely reported than the types of spontaneous cases considered above and in that poltergeist outbreaks last over a longer period of time, typically weeks or months, but sometimes several years.  A poltergeist disturbance typically involves strange physical events that occur repeatedly in a specific location or in the vicinity of a specific person or group of people.  

These physical phenomena generally include inexplicable movements of objects, such as a glass spontaneously flying off a kitchen table and hitting the kitchen floor at a considerable lateral distance from the table.  Sometimes quite large objects such as heavy cabinets are involved in such movements. Frequently the motion of the object is described as being unusual in terms of curved trajectories or abnormal slowness of flight.  Levitation effects have also been reported.  In such cases, the beginning of the object’s motion is hardly ever observed.  This is sometimes called the “shyness effect,” and it has been interpreted by some observers as evidence for an inhibiting effect of observation, while for others it suggests the possibility that the motions may have been fraudulently produced.  William Roll (1977a), perhaps the world’s foremost investigator of poltergeists, attributes the failure to observe the beginnings of movements to the fact that people do not typically attend to an object until after it is already moving.

Apparent materialization and teleportation effects are also reported. Occasionally, rocks are reported to materialize inside a room and drop to the floor. An apparent teleportation event might involve the sudden disappearance of an object at one physical location and its reappearance at another.  Objects in poltergeist cases are usually inferred to have been teleported when they are found at an unexpected location.  Again, the actual moments of disappearance and rematerialization are almost never witnessed.

Another frequently occurring poltergeist effect is the aberrant behavior of electrical apparatus.  In some instances, machines such as radios, lights, and dishwashers are inexplicably turned on or off.  Strange sounds, most prominently including rapping, are sometimes heard in poltergeist cases.  Less frequently, apparitions or disembodied voices are perceived, although these are more commonly a feature of hauntings, as will be discussed below.  Truly strange phenomena such as showers of rocks or even frogs on or toward a house, as well as the spontaneous ignition of fires, have been reported. 

The term “poltergeist” literally means “noisy ghost,” and poltergeist phenomena were sometimes suspected to be caused by such entities. (Some writers still assert that spirits of the dead may be involved in some poltergeist cases, as will be discussed below.)  It has been discovered that poltergeist phenomena generally tend to center around a single person or group of persons in that the phenomena only occur in their presence and in their immediate spatial vicinity.  Such a person is called a focal person or, less commonly nowadays, a “poltergeist agent.”  The prevailing view among those parapsychologists who believe that some poltergeist effects are truly paranormal is that the focal person or persons cause the poltergeist phenomena through the (largely unconscious) use of their psychokinetic powers.  For this reason, many parapsychologists use the term “recurrent spontaneous psychokinesis” or “RSPK” to describe such outbreaks.  Skeptics, on the other hand, maintain that the focal person produces such effects through fraud and trickery.  They also believe that some residual effects may be due to the witnesses’ misinterpretation of normal physical events.

Three Case Studies

 We will now consider three poltergeists cases in some detail.

The Rosenheim Poltergeist.  One famous case that centered on electrical apparatus was the Rosenheim poltergeist, investigated by the German parapsychologist Hans Bender (1968). The events in this case occurred in a lawyer’s office in the town of Rosenheim, Bavaria, in 1967.  Neon lights were frequently found to be nonfunctioning and occasionally to have been unscrewed from their sockets.  Electrical light bulbs exploded, bangs were heard, and electrical fuses blew for no apparent reason.  The developing fluid in the copying machine was repeatedly found to have been spilled.  The office telephones became disturbed, calls were cut off, and occasionally all four phones would ring simultaneously, with no one on the line.  The telephone bills were inordinately high and reflected large numbers of calls to the number announcing the time of day.  Large deflections in the power supply were found to coincide with some of the phenomena, and these continued even after a special power supply was installed to circumvent the problem.

The phenomena seemed to center around a 19-year-old girl named Annemarie Schneider.  The power supply surges often occurred when she arrived for work.  When she walked down the corridor, the electrical lights would start swinging behind her as she passed, a phenomenon that was successfully videotaped.  When light bulbs exploded, the fragments tended to fly toward her. In general the phenomena tended to occur only in close proximity to her.

Two physicists from the Max Planck Institute were called in to monitor the power supply.  They observed electrical surges accompanied by loud cracks, such as those produced by electrical sparks.  They were able to rule out several normal causes, but were unable to explain the surges.

Paintings began to swing and rotate.  These motions were also captured on videotape.  Drawers came out by themselves, documents were found to have been displaced, and at one point a 175 kilogram cabinet moved 30 centimeters from the wall.

Toward the end of the manifestations, Annemarie was getting more and more nervous and began to display hysterical contractions in her arms and legs. When she was on leave from the office nothing happened, and when she departed for another job, the phenomena ceased altogether (although they started up at her new place of work!).

The Rio Tercero Poltergeist.  A more recent, rock-throwing poltergeist is reported by Parra (2004).  The phenomena occurred in the city of Rio Tercero in the province of Cordoba, Argentina and began on February 15, 2004 and continued through May 18, 2004 (the date when Parra’s article was written).  The phenomena consisted entirely of the anomalous appearance and movement of stones.  The size of the stones involved were typical of those found in the Cordobese hills as well as on the road to the family’s house.  The stones increased in weight as the phenomena progressed, eventually reaching a weight of 1.3 kilograms.  The stones broke several windows and blinds, including the windscreen of the family’s car.  

The family initially thought that someone was throwing the stones and had the house surrounded by 16 policemen.  No stone thrower was detected and several policemen observed that the stones sometimes followed “impossible trajectories.”  All the family members, the sheriff and many of the neighbors attributed the events to the psychic powers of Andres, an 18-year-old boy living in the house.  The stones only entered the house when Andres was present and awake.  Also, no phenomena were reported during a 17-day period during which Andres was hospitalized.

At one time, Andres’ 44-year-old mother Monica was reading to her son Ezequial when a stone passed between them without hitting either of them and then came to a sudden stop on the table.  In Monica’s view, the momentum of the stone should have caused it to continue to slide on the table rather than coming to a sudden stop.

At one point, the family heard a loud noise and then found a stone embedded in the television set.  All windows and doors were shut at the time of this incident, and Andres was standing in the living room.  Shortly later, another stone broke a large window and curtain. Another impact on the television screen occurred when Andres and the family dog were playing in the kitchen.  Andres’ sister Denise felt a strange sensation, which she described as somewhat like a breeze, just prior to hearing the impact of the stone on the television set.  An older sister, Veronica, reported that a stone came from behind her (Andres was visible at the time) and left a small scratch on the television set and cabinet before hitting the window violently.  She described the trajectory of the stone as highly anomalous.

Andres was taken to a psychiatrist, who found that Andres frequently manifested aggression toward family members, but seldom were these aggressive impulses directed toward strangers.  Parra’s own psychological testing indicated that Andres manifested emotional instability, irritability, impulsivity and feelings of inadequacy.  Andres has also been diagnosed as hyperactive as well as suffering from neurological disorders involving the frontal lobes.  Parra also notes that Andres suffers from photosensitive epilepsy and has been subject to convulsions since age 12 and “blank spells” since age 9.  At the time of the disturbances, he was taking anticonvulsive and antiepileptic drugs and receiving neuropsychological treatments.      

The Oakland Poltergeist.  A poltergeist case involving a variety of phenomena was reported by Hastings (1978).  The phenomena occurred in a business office in Oakland, California, and seemed to center around John, a 19-year-old typist. The reported phenomena included the malfunctioning of telephones and typewriters, the breakage of coffee cups and glasses, and the movement of heavy objects.

Many of the anomalous movements involved falling objects.  Phones and a glass ashtray fell off desks, usually with no witness present to observe the motion.  One 15-year-old witness claimed to have seen (out of the corner of his eye) a stapler move off the left side of a table and fall to the floor, landing about three and a half feet from the table.  A fluorescent tube from a light fell, although the only one present at the time of this event was the focal person, John.  A second tube fell when another witness was in the room but was distracted by a phone call.  John was present on this occasion also.  A large number of other objects were discovered to have fallen.  In some instances, the objects were heard to fall by someone outside of the room involved.  When these witnesses entered the room, no one was present.  A floor plan of the office, however, reveals that most rooms had multiple exits.

Exploding coffee cups also figured prominently among the events.  In one case, a witness saw a cup explode without John touching it (he was adjusting a clip-on bow tie at the time).  No trace of explosives was found.

Cabinets were seen to undergo strange movements on two occasions. In one instance, a cabinet was observed to rotate 90 degrees and then to fall over.  Witnesses claimed that John was six feet outside of the room at the time of the incident.  In all of the above incidents, John was either present or in an adjoining room at the time of the event.

At one point a water cooler fell over.  John claimed to have been in the adjoining room at the time; however, his trouser cuffs were wet, and he was later observed to be picking glass fragments from them.  The police took John to the station for questioning, whereupon the phenomena ceased except for a brief resurgence on one occasion.  John confessed to the police that he had used tricks to produce the effects, such as pushing over the water cooler and throwing light bulbs behind his back.

Psychological testing showed John to be under a great deal of tension.  Personality testing, including the California Personality Inventory and the Thematic Apperception Test (TAT), revealed prankster tendencies, with the TAT indicating a large amount of projected aggression.  John was also under a great deal of stress.  He was a slow worker and was constantly being reprimanded by his bosses.  In addition, he was newly married and making double payments on his car.

Arthur Hastings, the case’s investigator, felt that some events were unlikely to be explained by fraud and may therefore represent true psi phenomena.  These events include the above-mentioned movements of the stapler and the cabinet.  Furthermore, Hastings observed that the smallness of the fragments of the “exploding” coffee cups make it seem unlikely that they were broken by impact.

Actuarial Investigations

As already mentioned, one of the most prominent investigators of poltergeist cases has been William G. Roll. In a series of publications (Roll, (1977a, 1977b, 1978a, 1978b, 1982b), he has reported the results of a statistical analysis of a sample of 116 published poltergeist cases.  Roll estimates that parapsychologists in the United States learn of approximately five promising poltergeist cases per year, of which two or three are investigated and about one per year reaches the professional literature in the United States.  On the other hand, in Palmer’s mail survey of the greater Charlottesville, Virginia area, six percent of the student respondents and eight percent of the townspeople claimed to have experienced poltergeist phenomena, suggesting that many more cases may exist than reach the attention of professional parapsychological investigators (Palmer, 1979).

Among Roll’s findings was that in the vast majority of cases (92 percent) the phenomena appeared to focus on the same object or area, inasmuch as the same object or area of the house was repeatedly involved in the effects.  The average duration of a case was about five months, although half of the cases lasted for less than two months.  In 41 percent of the 105 cases that involved moving objects, the objects displayed unusual trajectories of movements, such as wavering, zigzagging and hovering.  In 17 percent of the cases, the apparent teleportation of objects was reported.  Such teleportation might involve an object previously inside a house suddenly appearing outside the house or the apparent passing of objects through ceilings or walls.  

Some of the poltergeist cases displayed features that are more commonly associated with hauntings.  Twenty-three percent of the Roll’s 116 cases involved apparitions or “hallucinations.”  These visual hallucinations included human figures, animals, demons and amorphous shapes.  In eleven percent of the cases, intelligible voices were heard; often these were associated with apparitions.  In five cases, one or more persons were wounded or slapped by an unknown agency or displayed stigmata (spontaneously appearing wounds).  In five cases people were pulled or lifted by an unseen force.  In most instances the victim was the poltergeist agent (or focal person).  

One recent such case with mixed features has been reported by Kokubo and Yamanoto (2003).  This case occurred in an apartment complex in Tomika-cho, Gifu Prefecture, Japan in 2000.  Among the phenomena reported were noisy footsteps (heard in more than half the apartments), sounds similar to the sonar signals of a submarine, the rapid death of flowers, two sightings of “ghosts,” anomalous movements of curtains and cans, a fan and a hair dryer that worked despite the absence of a power supply, the turning of a doorknob, the spontaneous opening of doors to two cupboards, the movement of a rice bowl from a cupboard, resulting in its being chipped, a television set that switched channels, a gas cooking stove that spontaneously turned on, the breakdown on several machines, the rotations of magnetic compass needles, and the malfunctioning of cameras.  The phenomena were reported by a variety of tenants occupying at least twelve apartments.  Notably, this case investigation did not identify a focal person.  

The British researchers Alan Gauld and Tony Cornell (1979) used a statistical technique called cluster analysis to examine reported cases of recurrent anomalous events, such as those in poltergeist cases and hauntings.  Their computer analysis indicated that the cases tended to fall within two primary “clusters,” meaning that the cases tended to group into two types with distinctive characteristics.  Furthermore, these clusters seemed to correspond to the traditional categories of hauntings and poltergeist cases. Haunting cases were longer lasting than poltergeist cases and tended to center on a house or location rather than a person.  Haunting phenomena were primarily nocturnal, as opposed to poltergeist phenomena, which are more likely to occur during the day, when the focal person is awake.  (No RSPK phenomena occurred with the focal person asleep in Roll’s 116 case sample.)  Hauntings are more likely to involve raps, imitative noises, voices, phantasms, luminous effects, and movements of doors and door handles. Poltergeist cases were found to be shorter in duration, especially if the focal person is quite young. Finally, poltergeist cases were more likely to involve thrown objects, displaced objects, and objects carried through the air.

Still, there are a few cases that display mixed features.  George Zorab and Andrew MacKenzie (1980) report a haunting case in which the phenomena seemed to center around two focal persons.  Zorab speculates that some hauntings may, like poltergeist outbreaks, center around a focal agent and suggests that haunting apparitions may represent actual physical objects that are materialized by the focal person’s psychokinetic powers.  A similar theory was proposed by D. Scott Rogo (1977).

H. W. Pierce (1973) also reported a case that seemed to display features of both poltergeist and haunting cases.  This case involved a split-level house. The upstairs apartment was occupied by Ellsworth Cramer, an industrial engineer, his wife Naomi, a psychiatric nurse, and their child.  The downstairs flat was occupied by Peter Henry, a nuclear training engineer, and his wife Claire.  All four were in their mid-twenties, and the men described themselves as cynical or skeptical about the existence of psychic phenomena.

Most of the events were witnessed by Naomi Cramer. She found her lights on repeatedly when they should have been off.  At one point she heard a switch click as the living room lamp turned on.  She found that the radio station had been changed when no one was in the apartment, and at one point she heard the radio come on spontaneously (it was tuned to a 24-hour broadcasting station at the time).  She then saw an “oblong white cloud” for five or six nights in a row sitting in a chair in the dining room table.  The cloud was about four feet tall. She was not initially disturbed by it, thinking that it was an illusion caused by light passing through the drapes, but after the third or fourth night, it “began to bother her.” She also reported hearing the cupboard doors in the downstairs apartment opening and closing when no one was supposed to be there.  At one point, she went to answer the phone after disassembling a salt shaker, leaving the pieces of the shaker on the table.  The pieces came flying at her, hitting the floor just behind her, traveling about nine feet laterally in the process. This scared her because she thought the manifestations were becoming hostile.

Later, she heard a thump and saw a “shadow” dart into the baby’s room.  Once, when she was downstairs, she heard a lot of noise in her apartment. When she went up to her apartment, the furniture had all been moved around. She thought it unlikely that an intruder had entered, as a ladder would be required to enter the apartment without going through the front entrance.

Once, when she was rocking in her chair, it started to rock more violently, causing her to jump up so that her baby would not be harmed.  Three days later, she heard “childlike laughter” while changing her baby.  It seemed to come from her baby, although the baby was definitely not laughing. The sound was loud enough to wake her husband.

At one point, Naomi was in bed when she heard the dog barking.  She ran into the living room, where the dog continued to bark.  There was a dancing cloud in the middle of the room, from which emanated a laugh “more eerie than childlike.”

Her husband, Ellsworth Cramer, confirmed that he had heard the childlike laughter, which woke him.  He also testified that he too found lights turned on and off unexpectedly and said that he saw a light in the lower hall seemingly turn itself off on one occasion.  He also reported seeing a mist, which was somewhere between three and four feet high, standing at the foot of his bed and that he saw it pass right through the door.

Claire Henry testified to finding lights on in both her apartment and Naomi’s when they should have been off.  She also saw a chair rocking by itself on two occasions.

Peter Henry stated that he saw a three-dimensional shadow.  He believes he was the first to see such a form, but says he did not mention it to the others.  He confirmed that he and his wife Claire both saw a rocking chair moving “several inches” up and down with no deceleration.  He lit a match and circled the chair to test for air currents and found none.  Later, he saw a rocking horse moving up and down in the closet.  He deemed it too dangerous to light a match on this occasion. He also heard a child’s giggle, which he described as “musical,” and had no doubt that it was the voice of a little boy.  No one focal person existed in this case, as no particular person’s presence seemed to be required in order for the phenomena to occur.  Pierce speculated that the agent could be the ghost of the son of the building’s former owner.  The son had manifested symptoms of childhood schizophrenia and hyperactivity.  He also was reported to have displayed strong hostility and frustration in expressing his needs and was subject to nocturnal roaming.  These are all features that one might associate with a living poltergeist agent, as will be discussed below.

Stevenson (1972a) has also argued that some poltergeist phenomena may be caused by deceased agents, and Irwin (1994) feels that it may be premature to adopt the theory that poltergeist cases are necessarily characterized by one living focal agent.  Irwin argues that sometimes several agents may be involved and that the rejection of the discarnate (dead) agent theory is just a special case of modern parapsychologists’ antipathy toward the idea of the existence of ghosts.

The Poltergeist Agent  

Focal persons were involved in 92 of the 116 poltergeist cases examined by Roll.  Most of the agents (61 percent) were female, although Roll notes that this proportion has declined over time and that the sexes are nearly equally represented in recent cases.  Poltergeist agents are also typically young.  Half the focal persons in Roll’s sample were under thirteen years of age, and Irwin (2004) reports that 70% of poltergeist agents are under twenty years of age.

Roll found that slightly more than half of the agents suffered from some form of “debilitating ailment.”  These ailments were often psychological or neurological in nature.  About a quarter of the agents had disorders involving seizures or dissociative states, including muscular contractions, convulsive disorders, fits, trances and so forth.  In 41 percent of the cases with focal persons, a change or problem in the home preceded the onset of the RSPK phenomena. (Such changes might include a move, illness or death.)

Roll conjectures that RSPK incidents may substitute for medical symptoms in some cases.  He and his co-investigator Steven Tringale report a case with features of both typical haunting and poltergeist phenomena in which there was an inverse relation between the RSPK phenomena and migraine attacks in the focal person (Roll & Tringale, 1983).  The witnesses in this case involved a married couple, Mr. and Mrs. Berini, and their two children.  This family experienced some rather bizarre phenomena in their house, which lasted from the time they moved in (May of 1979) until late August of 1981.  The phenomena began when Mr. and Mrs. Berini heard a voice at night that seemed to belong to a young girl, who gave her name as Serena and who was crying for her mother.  Mr. Berini’s father later informed him that his sister Serena had died in the house at the age of five.  Three of these voice incidents occurred on the night preceding a death or an illness (respectively, the daughter’s tonsillectomy, a stroke suffered by Mrs. Berini’s grandmother and her later death).

In March of 1981, Mrs. Berini awoke and saw the figure of an eight- to nine-year-old boy, dressed in white.  Mr. Berini thought it might be Giorgi, his father’s brother, who had died at eight and was buried in a white communion suit.  Four days later, Mr. Berini saw a similar apparition, which seemed to be trying to pick up the rug in the hallway.  They later removed the rug and the floor boards and found a medallion of the Virgin Mary underneath the floor. The apparition continued to appear sporadically, two or three times a week.  It occasionally made short statements, sometimes in response to questions.  On some of these occasions only one of the Berinis saw the figure.  The apparition seemed to cause physical movements, including the repeated opening and closing of the closet door.  After two attempts by Catholic priests to exorcise this ghost, it seemed to depart.

Unfortunately, it was soon replaced by another less savory figure, a dark, caped and humpbacked entity.  This figure was first seen by Mr. Berini, with Mrs. Berini seeing it a few nights after its initial appearance.  On one occasion when Mr. Berini and his mother were in the bedroom, he saw it twice, but she saw nothing.  This bestial figure was not particularly well-behaved during its week’s tenure in the Berini household, and it had the temerity to say “really disgusting things” in a gruff male voice, usually when Mrs. Berini was attempting to pray.  When they inquired as to its identity, it replied “I am a minister of God.”  Lest we conclude on this basis of this last remark that the exorcisms had been successful, it should be noted that the RSPK phenomena started up soon after this ethereal “minister” appeared.  In fact, the night after his arrival, the bedside phone kept flying across the room and the bedside lamp fell on Mrs. Berini’s head several times.

Further incidents involved the breaking of dishes, crosses and religious statues.  The furniture then seemed to get restless. A china cupboard turned over four times, and a bookcase on the top landing moved downstairs twice.  The daughter’s desk meandered out of her room and down the stairs.  The retractable staircase to the attic opened and slammed shut repeatedly, causing the ceiling in the hall to crack.  The incidents continued until the daughter’s birthday in August, when a carving knife was found stuck in the kitchen table.  The family then moved out, and a priest performed a third exorcism. This final exorcism attempt was apparently successful, as the phenomena finally ceased.

Some of the events were witnessed by outside observers, including a friend of the son’s, a neighbor, and Mr. Berini’s sister.  These include the flight of a candle, the movement and toppling over of a table lamp, the levitation of a comb, and one of the bookcase’s frequent sojourns down the stairs.

This was a particularly nasty poltergeist that frequently attacked people.  Mr. and Mrs. Berini and their son were all hit by moving objects.  On four separate occasions when they were in bed, Mr. Berini saw his sleeping wife lifted from the bed and moved out into the room, where she was dropped to the floor. In fact, the poltergeist seemed to have a particular aversion to Mrs. Berini.  Once she experienced a burning sensation, and three bleeding scratches were found on her chest and an upside down cross was found to be scratched on her back. She was scratched twice more. On one of these occasions, her sister was present and was on the phone to the police. Her sister experienced a burning sensation on her face and found a scratch on her own cheek.

The phenomena seemed to center around Mrs. Berini.  Virtually all the incidents took place when she was in the house, and she tended to be the person closest to any strangely behaving object.  She was also the one who experienced the first two apparitions.  She had suffered from migraine headaches and vomiting since she was a child.  The phenomena tended to occur during periods when she was free of migraine attacks.  Roll and Tringale speculate that the RSPK manifestations could have served as a substitute for the migraine symptoms.  They compare the apparitions in this case to the visual “auras” that frequently precede epileptic attacks and speculate that such apparitions may be an externalized form of such auras.  In fact, Roll (1978a) had earlier postulated that both apparitions and voices in such cases may represent externalized hallucinations.   

In an article written with Elson de A. Montagno, Roll draws further parallels between RSPK phenomena and the symptoms of epilepsy.  Both types of phenomena are most frequently exhibited by people in their teens.  Knocking and rapping sounds in poltergeist cases may be analogous to the rhythmic tonic-clonic movements of epilepsy.  Sudden movements and the existence of visions and apparitions constitute other similarities.  Finally, Montagno and Roll note that the onset of RSPK phenomena frequently coincides with the abatement of hysterical or epileptic symptoms in the agent (Roll & Montagno, 1983). These facts, combined with the high incidence of convulsive-dissociative disorders in poltergeist agents, lead Roll to suspect that some forms of brain dysfunction may play a role in causing RSPK phenomena.  Irwin (1994) has, however, argued that Roll’s epilepsy theory of RSPK phenomena may be premature.  He notes that only four percent of Roll’s agents manifested clear-cut symptoms of epilepsy per se, and that this may not represent much of an elevation above baseline rates in the general population.

Many other investigators have postulated that psychopathology or aggression in the agents may be responsible for the generation of the psychokinetic phenomena.  Indeed, for years the stereotypical picture of the poltergeist agent was that of the disturbed adolescent girl, which formed the basis of Carrie, Stephen King’s first best-selling novel.  The psychoanalyst Nandor Fodor (1964) saw RSPK phenomena as being analogous to hysterical conversion symptoms resulting from emotional tension.  D. Scott Rogo (1974) postulated that RSPK phenomena are due to projected hostility and constitute a psychokinetic form of the “acting out” of displaced aggression.  In support of this contention, he cited a case in which RSPK phenomena (raps) occurred during a psychotherapeutic session with a 32-year-old man who claimed to be persecuted by a poltergeist.  Owen (1978) cites a number of poltergeist cases in which the focal person displayed signs of hysteria.

Alfonso Martinez-Taboas and Carlos Alvarado (Taboas, 1980, 1984; Taboas & Alvarado, 1981) have criticized the body of research indicating psychopathology in poltergeist agents.  They argue that much of this evidence has been produced through clinical interviews in which the interviewer knew that the subject was a suspected poltergeist agent.  The interviewer may thus have been biased by this knowledge and his or her own stereotypical ideas about poltergeist agents.  They also fault the researchers for their use of unreliable projective psychological tests, such as the Rorschach inkblot test, which are open to multiple interpretations, as well as the fact that the researchers may be seriously underestimating the prevalence of psychological disorders in the general population.

The Problem of Fraud  

Skeptics contend that most, if not all, poltergeist effects are produced by trickery on the part of the apparent poltergeist agent, often in an attempt to gain attention.  In some cases direct evidence of such fraud on the part of the focal person has been obtained.  Roll (1969, 1972) used a one-way mirror to observe a 12-year-old focal person in another room together with his grandmother.  His coinvestigator (J. G. Pratt) saw the agent hide two measuring tapes behind his shirt and then later throw them after his grandmother.  The grandmother then reported this as another poltergeist incident, evidencing no suspicion of any fraudulent activity.  The boy was later administered a polygraph test.  That test indicated that he was telling the truth when he was in fact lying in denying that he had thrown the tapes (which shows you why the results of polygraph tests are not admissible as evidence in most courts).  Roll (1977a) reports another case in which the poltergeist agent was found to be producing “knocks” by stamping his foot.

James “the Amazing” Randi (1985), a skeptical magician who has written several books debunking parapsychology, has presented photographic evidence suggesting that one of Roll’s subjects, Tina Resch, the focal person in a poltergeist case in Columbus, Ohio, threw a phone when no one was looking and produced an apparently anomalous movement of a couch by hooking it with her right foot.  A videotape also suggested that she pulled a lamp toward her in order to make it fall.  Roll (1993) has, however, continued to argue for the genuineness of the RSPK phenomena in this case, noting that Tina was not in the area when many of the events occurred.  He also documents an apparent attempt by the prominent skeptic Paul Kurtz to doctor the evidence in this case by implying that two photographs that were actually taken an hour apart were taken within seconds of each other.  On the other hand, the fact that Resch was recently sentenced to life in prison for the murder of her daughter does nothing to enhance her credibility as a poltergeist agent (see Frazier, 1995, and Roll & Storey, 2004, for the details of the circumstances surrounding this murder).  Roll and Storey (2004) also note that Resch’s phenomena displayed the “shyness effect” that is characteristic of many poltergeist cases in that no ostensible psychokinetic phenomena were observed if Tina knew she was being filmed.  More generally, the term “shyness effect” is used to denote the fact that the beginnings of object movements are rarely observed in poltergeist cases.  The “shyness effect” is consistent with what would be expected if the poltergeist phenomena were being produced through fraudulent means.  The shyness effect is thus evidence in favor of the fraud hypothesis.

Roll (1977a, 1977b) notes that the focal person was detected in fraud in 19 of the 92 poltergeist cases in his sample in which a focal agent could be identified.  Gauld and Cornell (1979) report a somewhat lower incidence rate of detected fraud.  Fraud was detected in 41 of the 500 poltergeist cases in their sample, yielding an incidence rate of eight percent.  Gauld and Cornell note that the initial stages of object movements in poltergeist cases are rarely observed, which would be consistent with the fraud hypothesis, as noted above.  Roll (1977b) notes that, in 105 cases involving anomalous object movements, visual fixation of objects by witnesses seemed to have an inhibiting effect in 47 cases and no effect in 43 cases. (In the remaining 15 cases, the effect of visual fixation could not be determined.)  Several writers, while admitting the existence of fraud in some cases, suggest that the fraudulent activity is merely the agent’s way of maintaining the attention he received when genuine phenomena were occurring. In particular, Munson (1987) attributes fraud in poltergeist cases to the agent’s “owning” of impulses (such as aggressive impulses) that were previously projected into the environment via PK.

Theories About Poltergeists  

Several writers have offered theories about how poltergeist effects are produced, assuming they are not the result of deliberate fraud.  G. W. Lambert (1955) proposed that reported poltergeist phenomena may be due to motion of underground water and the resulting stress on houses.  While it is easy to imagine that poltergeist raps and creaks might be due to such motion of underground water, it is hard to believe that such motion could produce the large horizontal movements of objects frequently reported in RSPK outbreaks.  In order to test Lambert’s theory, Gauld and Cornell (1979) conducted an extraordinary experiment in which houses were mechanically shaken. They concluded that serious structural damage to, and even collapse of, such houses would in all likelihood occur well before any substantial lateral movements of objects were induced. They also feel that such jolting and vibrations would be immediately apparent to anyone inside the house. With regard to Lambert’s observation that poltergeist cases tend to cluster around bodies of water, Gauld and Cornell note that this may simply be due to the fact that the population in general tends to congregate in such locations.

William Roll, Donald Burdick, and William Joines (1973) have postulated that RSPK agents produce a type of force field in the area surrounding their bodies. Based on an analysis of the locations, directions and magnitudes of movements of objects relative to an ostensible poltergeist agent, they suggest that these movements could have been produced by three rotating “beams” of force emanating from portions of the agent’s body.  They do not hazard a guess as to the type of force involved or as to how the field is generated.  As arbitrary models can rather easily be constructed to “retrodict” observed patterns of movements, their model must await confirmation with new poltergeist agents.

More recently, Roll (2003) has postulated that poltergeist effects may be produced through the focal person’s influence on the “zero point energy” field pervading the universe, thus temporarily freeing the object from the force of gravity.  He also cites measurements indicating weight changes in two poltergeist agents, possibly indicating a transfer of mass-energy between the agent and the affected object.

Michael Persinger and Robert Cameron (1986) have proposed that some poltergeist episodes may be a product of electromagnetic fields produced by geological stresses. They postulate that extremely low frequency (ELF) components of such fields may directly stimulate the brains of persons involved in such cases and induce apparitional experiences or hallucinations of an olfactory or auditory nature.  They further suggest that electromagnetic transients may be responsible for such phenomena as current surges, anomalous telephone rings and light bulb failures.  They report on a case in Sudbury, Ontario, which they feel might support such an interpretation.


Poltergeist cases constitute a dramatic and striking category of possible spontaneous psi phenomena. The number of agents who have been detected in fraud together with the “shyness effect,” wherein the beginnings of motions are rarely observed, suggest that RSPK phenomena will have to be approached cautiously and investigated thoroughly from a skeptical viewpoint before they can be accepted as genuinely anomalous phenomena.  Investigations of the personalities and other characteristics of poltergeist agents will have to be conducted more rigorously and with more appropriate experimental blinds before they can be considered definitive.  Finally, theories to account for poltergeists will have to be constructed that are fully capable of predicting new phenomena rather than merely “retrodicting” phenomena that have already occurred. Theories failing to meet this criterion may well have to be considered as no more scientific than one of Rudyard Kipling’s “Just So” stories.

Miscellaneous Phenomena

 There are a variety of phenomena suggestive of the operation of psi that fall outside of the category of spontaneous psi experiences in that the phenomena are deliberately induced but also occur to a large extent outside of the laboratory and thus may involve a number of uncontrolled factors.  These phenomena include dowsing, psychic prognostication, psychic healing, and the work of psychic detectives.  We will also examine in this section a few instances of truly strange phenomena, including the alleged ability of certain Christian saints, to levitate, an instance of possible weather control by a Tibetan shaman, and spontaneous human combustion. 

Psychic Predictions. 

 Every year, several tabloids, including the National Enquirer and the always thought-provoking Weekly World News, publish the predictions of “leading psychics” for the upcoming year.  It is not easy to perform a statistical analysis on such predictions to see whether or not they come true more often than one would expect by chance. Nevertheless, it is safe to say that such predictions are not in general very accurate. 

Recently, Farha (2005) reviewed the predictions made for 2004 by psychic Sylvia Browne on The Montel Williams Show (an American television talk show) on December 31, 2003.  Unlike many psychics, Browne’s predictions were relatively mundane and reasonable extrapolations from current events.  Nonetheless, most of Browne’s predictions were not fulfilled, including her predictions that American troops would be out of Iraq by June or July 2004, that Osama bin Laden was already dead, that the fashion mogul Martha Stewart would not go to jail (she entered prison on October 8, 2004), and that Pope John Paul II would die in 2004.  This last prediction was a reasonable extrapolation from the Pope’s failing state of health.  Nonetheless, the Pope did not die until April of 2005.

Sometimes psychics go out on a limb and make predictions that are far less likely than those made by Brown.  Emery (1996) for instance observes that Hugh Hefner did not give up his Playboy empire to become a cultivator of sunflowers, as predicted by psychic Shawn Robbins, no child genius constructed a working time machine from parts of a microwave oven as an entry in a seventh grade science fair, as predicted in the National Enquirer, and disgraced skater Tonya Harding did not attempt to open the nation’s first all-nude ice skating rink, as forecast in the same publication.  Predictions such as these seem to be offered in an attempt to entertain the audience and are not to be taken seriously.

Radford (2005b) has reviewed the predictions of several psychics for 2001 and found no mention of the September 11, 2001 terrorist attack on the World Trade Center and the Pentagon.   Similarly, Posner (2005) notes that the prediction of three psychics in the newspaper Florida Today that Hurricane Jeanne would miss Florida failed to be fulfilled.

In some cases, an apparently successful prediction may be fabricated. Quite a splash was made in the early 1980s by a videotape of an apparently accurate prediction of the assassination attempt on President Ronald Reagan by John Hinckley that was allegedly made by psychic Tamara Rand on a talk show.  President Reagan was shot in the chest on March 30, 1981, by John Hinckley, a blond-haired former member of the American Nazi party.  Hinckley claimed that he made the assassination attempt in order to impress actress Jodie Foster, who had played the subteenage flame of a psychotic assassin in the movie Taxi Driver.  The tape of the alleged prediction was broadcast on NBC’s Today show and ABC’s Good Morning America as well as on Ted Turner’s Cable News Network, on April 2, 1981.  The tape showed Rand, a Los Angeles area psychic who catered to Hollywood celebrities, making the prediction that Reagan would be shot in the chest by a sandy-haired young radical having the initials “J. H.” and that the assassin’s name would be something like “Jack Humbley.”  Rand further predicted that the assassination attempt would take place during the last week in March or the first week in April.  The tape had supposedly been aired on March 28, 1981, two days before the actual assassination attempt took place.  It turned out that no such tape had been aired and that the tape was in fact made the day after the assassination attempt but was fraudulently dated to make it appear to have been made before the attempt.  Dick Maurice, the host of the talk show in question, confessed to involvement in the hoax.  (See Frazier & Randi, 1986; Lyons & Truzzi, 1991; and Nickell,1994, for an account of the Tamara Rand hoax.)

Sometimes predictions may be worded so vaguely that many events may be interpreted as fulfilling them.  This is particularly true of the poetic quatrains of the sixteenth century prophet Nostradamus, as has been pointed out by Christopher (1970).  One of Nostradamus’ most prophetic quatrains begins, “The King-King will be no more, of the Gentle One destroyed” (Christopher, 1970, p. 106).  This was taken (after the fact) to be a prediction of the slaying of Henry III, King of both Poland and France, by a man named Clement (a synonym of “gentle”).  Nostradamus’ quatrains are, however, like Rorschach inkblots, onto which the reader may project any message she wants. For instance, Paul Kurtz cites the following quatrain (Kurtz, 1986, p. 262).

An emperor shall be born near Italy

Who shall be sold to the Empire at a high price.

They shall say, from the people he disputed with,

That he is less a prince than a butcher.

As Kurtz points out, this particular quatrain is so vaguely worded that it could be taken as a prediction of the reign of Napoleon, Hitler or even Ferdinand II, the king of Bohemia and Holy Roman emperor.  Such vague predictions as are contained in Nostradamus’ quatrains are effectively no predictions at all; as no dates or specifics are given, they can be interpreted to fit any suitable event in the last four centuries.

Occasionally, formal divination systems such as the I Ching or tarot cards are employed to make predictions, read a person’s character, or offer advice.  As the message of the cards, yarrow stalks or stars may be interpreted in several ways, there is an opportunity for the reader or diviner to select the appropriate interpretation by means of intuition or even ESP.  There is also the “Barnum” effect, the tendency for people to believe that a vaguely worded statement holds a deep message meant specifically for them.  Most studies that have been conducted to test the efficacy of such divination systems have yielded null results.  For instance, in a test of divination with tarot cards, Blackmore (1983b) found people unable to distinguish between tarot card readings meant for them and readings meant for other people.  Roney-Dougal (1991) repeated Blackmore’s experiments and obtained essentially the same results.  Two similar experiments with the I Ching divination system also produced null results (Rubin & Honorton, 1971; Thalbourne, Delin, Barlow & Steen, 1992-1993).

Psychic Detectives

There are frequently accounts in the popular press of cases in which psychics have been able to use their powers to help the police solve crimes. Unfortunately, newspaper accounts are not always noted for their accuracy. Studies of psychic detectives from a skeptical vantage point have been published by Melvin Harris (1986) and Piet Hein Hoebens (1982, 1986a, 1986b).  Hoebens focused his investigations on the Dutch psychic Gerard Croiset and his primary investigator from a parapsychological point of view, Wilhelm Tenhaeff.  According to popular accounts, Croiset has displayed an astonishing success in helping the police find bodies and solve crimes.  Yet when Hoebens interviewed the Utrecht police, they denied that any of Croiset’s attempts to locate missing persons or to solve crimes had been successful.  Hoebens also notes certain inconsistencies in Tenhaeff’s accounts of Croiset’s successes.  In addition, Tenhaeff distorted many of Croiset’s statements in his summaries of them. Initially vague statements were made to seem much more detailed and accurate than they really were.  Errors made by Croiset were deleted.  Tenhaeff also distorted his descriptions of confirming events to make them better conform to Croiset’s predictions.  Hoebens also reviews one instance of an apparent gross falsification by Tenhaeff. Thus, what you read in the popular press may not necessarily correspond to the facts when it comes to the area of psychic detection.

Similarly, Radford (2005a) notes that the Oxford Press reported “uncanny similarities” between the location where the body of Charles Capel, a wandering victim of Alzheimer’s disease, was found and the description provided by psychic detective Noreen Renier.  However, Radford notes that the police, acting on this description could not locate Capel’s body.  After several months, Capel’s body was found less than a mile from his home.  Radford points out that missing Alzheimer’s patients are generally found less than a mile from home and that Renier’s description of a wooded area would match most locations in the area of Capel’s house.

Lyons and Truzzi (1991) report on the fairly impressive case of psychic Greta Alexander, who was called in by police to find the missing body of Mary Cousett, a woman who had disappeared in April of 1983.  Alexander correctly predicted that the body would be found near the intersection of several roads, that it would be missing a leg or foot, that the head would not be found with the body, and that it would be found by a man with a crippled hand.  In fact, the body was found in such a location by an officer who had had several fingers on his left hand damaged in a drill press accident.  It should be noted, however, that these statements were embedded in a fairly large number of other statements that were either too vague to be called predictions or were in fact incorrect.  Further, the body was found outside the area on the map circled by Alexander.

In a recent investigation of four prominent psychic detectives, Nickell (2005a) found that the police officers involved generally deny that they have worked with such detectives or that the psychic detectives provided any useful information.  Nickell notes that the predictions offered by such psychics are often vague and can be “retrofitted” to fit the facts (such as when an abandoned railroad track is interpreted as a “bridge”).

What is clearly needed are more rigorous and skeptical field investigations of psychic detectives. It would also be possible to conduct laboratory studies in a forensic format with such persons. To date, only a handful of studies have been conducted (see Wiseman, West & Stemman, 1996b, for a review of such studies).  The preliminary results indicate that “readings” provided by psychic detectives are no more accurate than those provided by normal persons claiming no psychic ability.  For instance, Wiseman, West and Stemman (1996a) report a controlled laboratory experiment in which the ability of three self-proclaimed psychic detectives to provide accurate descriptions of (previously solved) crimes was put to the test.  When provided with materials related to the crimes, the psychic detectives were no more successful than a control group of three students claiming no psychic abilities in providing accurate details relating to the crimes. 

Thus, the evidence for psychic abilities on the part self-proclaimed psychic detectives is less than compelling.


Dowsing is a technique in which the practitioner (called a “dowser”) employs a device such as a forked stick or dowsing rod to locate some object (usually a body of underground water, although other sorts of objects such as buried mines have served as target objects).  When the dowser is located over the target object, the dowsing rod signals that fact by making a movement.  Most scientists believe that the movement of the rod is caused by unconscious muscular movements on the part of the dowser, although Kaufman (1979) has reported strain gauge measurements on dowsing rods that he claims reveal a force unexplainable by gravity, muscular jerking or thumb pressure.  As the dowser is in physical proximity to the target object, it is possible that some physical signal serves as a sensory cue to guide him to the object.  Thus, dowsing may not involve the operation of ESP at all.  Kaufman, for instance, notes that many geological features are associated with magnetic anomalies and that human beings have been shown to be capable of detecting such magnetic fields.  Such sensory cueing may be less prominent in cases of “map dowsing,” in which the practitioner holds his apparatus over a map of the area rather than walking over the area itself.  Even maps, however, provide clues as to the geophysical makeup of an area.

Hansen (1982), in a detailed review of the literature relating to dowsing, concluded that many of the studies of dowsing that have been conducted have used quite sloppy experimental procedures and in many cases the reporting of the methodology that was used is unclear.  Despite these shortcomings, many of the studies showed dowsing techniques to be ineffective.  Since Hansen’s review, Hans-Dieter Betz has reported a massive field study of dowsing in several countries (Betz, 1995a, 1995b).  Betz’ results indicate that the use of dowsing can enhance the efficacy of searches for underground water sources.  As with virtually any field study, Betz’ methodology is not adequate to rule out the hypothesis that the dowser may be responding to physical cues. Because of the poor reliability of the dowsing procedure and the methodological inadequacies of field studies, it is not clear that dowsing offers a more effective means of demonstrating the existence of ESP than do more traditional ESP experiments.

Psychic Healing

 “Psychic healing” is a generic term employed to describe a variety of techniques whereby diseases and other ailments are healed or alleviated by an apparently paranormal process. Stanley Krippner (1980) has proposed a typology of practitioners of such healing techniques, which he calls “folk healing.”   Krippner’s first category of folk healers is that of shamanic healers.  Shamans are persons, usually in “primitive” cultures, who are ostensibly able to enter a trance and visit the world of spirits, a vocation typically entered as the result of a “calling” in youth.  Their healing rites may consist of literally retrieving lost souls or departed animal spirit guardians that have deserted the ailing patient.  

McClenon (2004) has hypothesized that humans have developed a genetic tendency to enter dissociative states, possibly due to shamans’ successful use of their psi abilities while in such states (although McClenon remains neutral regarding the question of whether psi actually exists).  He notes that shamanism is universal among hunter-gatherer societies and that cave art suggests than shamanism has been practiced for more than 30,000 years.  He notes that humans’ dissociative/hypnotic capacities could not increase infinitely, because these traits had negative consequences, including psychosomatic and dissociative disorders.  It should added that a complete dissociation from the physical body would be maladaptive in terms of survival, thus the development of some sort of “filter” restricting the mind’s attention largely to the needs of the physical organism, as suggested by Bergson (1914), may be necessary.

Spiritist healers comprise Krippner’s second category of psychic healers. Spiritist healers are distinguished from shamanic healers by the fact that the former undergo possession by a spirit in the course of performing their healing rituals.  The Condomble and Umbanda sects of Brazil are examples of this tradition. Krippner’s next two categories are esoteric healers, who follow an occult tradition such as alchemy, astrology, tarot-reading, or tantric Buddhism, and religious ritual healers, whose healing takes place in the context of a religious ritual, such as a Mexican sacred mushroom ceremony.   Krippner would classify faith healers, such as Kathryn Kuhlman, who operate in the context of a Christian religious service, as religious ritual healers.  

Krippner’s final category is that of intuitive healers, who (unlike shamans) undergo no special training or initiation but who chose their vocation based on an inner sense of a calling (sometimes described as a “call from God”).  Such practitioners frequently employ the technique of laying-on-of-hands, which has been the subject of much parapsychological investigation (to be discussed below) and often describe themselves as tuning in to a “universal energy field.”  As examples of this type of healer, Krippner offers Olga Worrall and Oscar Estabany, both of whom have been extensively studied by experimental parapsychologists.

For the purposes of the present analysis, we will subdivide psychic healing by the type of technique employed rather than by the type of practitioner, as there is considerable overlap in the techniques employed by practitioners of different Krippnerian types.

Faith healing. The term “faith healing” will be used primarily to refer to healing carried out in the context of a (usually Christian) religious meeting in which ailments are ostensibly cured by the power of God or the patient’s own religious faith rather than the cure being ascribed to any “energy” emanating from, or physical manipulation performed by, the healer.  Faith healing may be accomplished with or without any physical contact between the patient and the healer. Extensive physical contact between the healer and the patient would probably result in the classification of the technique as either psychic surgery or the laying-on-of-hands (to be discussed below).  Examples of modern day faith healers would be Kathryn Kuhlman, Oral Roberts, Peter Popoff, Ernest Angley, the noted Christian broadcaster and former presidential candidate Pat Robertson, and the more infamous Jim Jones.

Some cures that occur in the context of faith healing may be due to the fact that the original ailment was psychogenic in origin.  Some apparently serious conditions, such as paralysis and blindness, may have no organic basis but may merely be hysterical symptoms that reflect the patient’s psychological distress.  Even apparently genuine physical conditions such as visible rashes, ulcers and asthma attacks may be aggravated or even caused by psychological factors. Such illnesses are typically referred to as psychosomatic illnesses to distinguish them from hysterical ailments.  Obviously, as both types of conditions are at least partially caused by psychological factors, it would not be surprising if a religious ritual, which may have a considerable emotional impact on the patient, had the effect of alleviating these symptoms.

Sometimes people with a genuine physical illness may experience a surge of excitement, possibly involving the release of endorphins (the brain’s “natural opiates”), during a religious ritual and may overcome their symptoms for a brief time.  (The alleviation of pain through the administration of placebos or hypnosis is a well-known effect and is thought to be governed by the release of endorphins in many cases.)  The symptoms may, however, return once the fervor of the ritual has waned.  For instance, Hines (2003) cites a case in which the faith healer Kathryn Kuhlman “healed” a woman who had cancer and who could only walk with a back brace.  The woman threw off the back brace and ran across the stage.  However, two months later the woman died from the cancer that Kuhlman had supposedly cured.  

Cases in which documented serious physical illnesses, such as cancer and lupus, were cured through faith healing do exist, although they are extremely rare; however, cancer and other serious illnesses do sometimes improve without medical intervention, in a process known as spontaneous regression.  What is needed in order to document the efficacy of faith healing are controlled studies showing that such spontaneous regression occurs more frequently among patients undergoing religious rituals than for control patients not undergoing such rituals.  Such studies have not been done.

The activity of the immune system and the course of diseases are known to be affected by psychological conditions such as stress.  It is well established that physical diseases occur more frequently following traumatic life events such as the loss of a job or the death of a spouse.  There are cases on record of voodoo death, in which a victim who learns that he has been cursed by a witchdoctor suddenly dies.  It is commonly thought that this is an example of what is known as parasympathetic death or “death by helplessness,” as described by Martin Seligman (1975).  In such a death, a person facing what he perceives to be a hopeless situation essentially relaxes himself to death, stopping the heart.  The central nervous system is also known to interact directly with the immune system through the hypothalamus, and immune responses in animals have been conditioned to occur in response to certain tastes or even in response to the presence of particular persons (Ader, 1981).  Thus, it might not be too surprising if participating in a faith healing ritual served to bolster a patient’s immune system.  This would not be a paranormal phenomenon, however, as the bolstering of the immune system could be due to the brain’s normal channels of influence over the immune system operating in response to suggestion.  Some evidence against the hypothesis that all forms of psychic healing are placebo effects or due to suggestion is provided by a survey conducted by Haraldsson and Olafsson (1980), in which they found that prior belief in the efficacy of psychic healing did not correlate with the perceived benefit the patient received from the healing session. Their study was not specific to faith healing, but encompassed healing in general.

Several faith healers have been exposed in using fraud to aid their practices.  James Randi’s book The Faith Healers (Randi, 1987) contains an extensive documentation of such fraudulent activity.  Perhaps the most common ploy used by faith healers is to “heal” a stooge sitting in the audience who is only faking an illness.  Morris (in Edge, Morris, Palmer & Rush, 1986) describes how the Reverend Jim Jones used such stooges and other forms of deception to dupe his followers into believing he had magical powers.  Some of these people later followed Jones into death in the infamous Jonestown massacre in Guyana, in which hundreds of Jones’ followers drank cyanide-laced Kool Aid at his command.

In general, there is no compelling evidence that any paranormal process is involved in faith healing. The more spectacular miracles are chiefly the result of fraud, and other cures may be due to the effects of suggestion and normal psychosomatic and psychoimmunological processes.

Psychic diagnosis. Some healers claim the ability to diagnose illness by psychic means.  One such person was Edgar Cayce.  Given the name and address of a patient, Cayce would enter a trance, diagnose the patient’s ailment and prescribe a (typically unorthodox) method of treatment.  Cayce’s recommended cures have been the subject of study by physicians at the Association for Research and Enlightenment, an organization dedicated to the study of Cayce’s readings based in Virginia Beach, Virginia.   James Randi (1979) has provided a skeptical analysis of Cayce’s diagnoses, pointing out that Cayce was often inaccurate and even provided diagnoses of people who were in fact already dead.  However, this negative evidence may not prove much, as Cayce’s proponents concede that he was accurate in only about one-third of the cases he attempted to diagnose.  A well-controlled statistical study might have settled the issue of whether Cayce displayed any paranormal ability in his diagnoses, but unfortunately Cayce died before any such study was conducted.

Randi (1987) has cast more definitive doubt on the paranormal diagnostic capability of the faith healer Peter Popoff.  In his services, Popoff claimed the ability to obtain the names and medical conditions of people in his audience through paranormal means (described as a revelation from God).  Randi and his associates were able to intercept a radio signal transmitted from Popoff’s wife to an earpiece worn by Popoff giving him names and medical data for various audience members. In this instance at least, the psychic diagnosis was achieved through fraud.

Ray Hyman, a well-known skeptic regarding psi phenomena, and his associates Richard Wiseman and Andrew Skolnick conducted a controlled experiment in which the claimed psychic diagnostic capabilities of a seventeen-year-old Russian girl, Natasha Demkina, were put to the test (Hyman, 2005). However, despite the fact that at least two of the investigators (Hyman and Wiseman) are known for their criticisms of flawed procedures in parapsychological experiments, their own experimental procedure allowed Natasha to see the subjects she was attempting to diagnose at short range.  Thus, she could have picked up sensory cues (e.g. breathing and movement patterns) that could have her helped to match medical diagnoses to subjects.  Interestingly, Hyman declared the experiment a “failure” despite the fact that Natasha successfully matched four of the seven diagnoses to the correct subject.  Such success would happen less than two times out of one hundred experiments by chance.  As one could not reasonably expect lower probabilities in any experiment with only seven trials, the results would actually seem to support the claim that Ms. Demkina can provide more accurate diagnoses than would be expected by chance. While this experiment is inconclusive regarding Ms. Demkina’s psychic diagnostic abilities due to the investigators’ failure to screen our sensory cues, it serves as a cautionary example regarding the interactions between parapsychologists and their critics.  

Psychic surgery. In the technique of psychic surgery, the healer purportedly enters the patient’s physical body, sometimes using only his bare hands, as in the case of the Philippine healer Tony Agpaoa, and in other cases using an unorthodox implement, such as the rusty knife wielded by the Brazilian healer Arigo (see Fuller, 1974, for a comprehensive discussion of the phenomena produced by Arigo). In a typical psychic surgery session, the healer might massage the patient’s stomach muscles, seemingly penetrate the abdominal cavity with his bare hands, and apparently remove a “tumor” (which is frequently immediately destroyed because of its “evil” nature).  Although bleeding may be profuse during the surgery, the alleged incision usually heals immediately, without a trace of a scar.

Psychic surgery is now widely regarded by scientists both within and outside the parapsychological research community as a fraudulent activity. The illusion of an incision is thought to be produced by kneading the patient’s skin.  The illusion of bleeding is achieved by the psychic surgeon’s releasing blood or some other red liquid from a source he has palmed as if performing a cheap magic trick.  The tumors removed by the surgeons are thought to be samples of animal tissue that have also been palmed by the surgeon.  An early investigation of psychic surgery by the American physician William Nolen (1975) failed to uncover even one case in which a physical illness that had been documented to exist before a psychic surgery session was found to be absent following the session.  Nolen also detected many instances of fraudulent activity on the part of the psychic surgeons he observed.  In one case, a “kidney stone” was found to be composed of sugar.  In an earlier investigation, Granone (1972) had found such “kidney stones” to consist of table salt and pumice stone.  David Hoy (1981) also describes sleight-of-hand techniques he witnessed during psychic surgery sessions, including the palming of objects.  Lincoln and Wood (1979) identified “blood” produced from a patient during psychic surgery as pig blood rather than human blood.  Finally, Azuma and Stevenson (1987) analyzed two more kidney stones removed from patients during psychic surgery and found them to be pebbles.  By now it should be apparent that the rampant fraudulent activity on the part of psychic surgeons casts extreme doubt on the hypothesis that any paranormal effect has been demonstrated in this procedure.

Laying-on-of-hands and remote healing. In both the technique known as the “laying-on-of-hands” and in the technique I will call “remote healing,” the healer is conceptualized as being the source or channel of a healing effect or healing “energy.”  The chief difference between the two techniques is that the laying-on-of-hands involves more or less direct physical contact between the patient and the healer, whereas the healer is isolated from the patient in remote healing.  In practice, the distinction between the two techniques becomes blurred by the fact that many experimental studies of healers who would normally use the laying-on-of-hands in their daily practice have of necessity used experimental protocols that remove the healer from direct physical contact with the patient to be healed or from the biological system to be influenced.  Unlike other forms of healing, a great many experimental tests of the efficacy of these two techniques have been performed.  A surprisingly high proportion of these experiments have yielded evidence of some sort of healing effect.  Healers have been found to be able to retard the growth of goiters in mice and to accelerate the recovery of such goiters (Grad, 1977), to speed the healing of experimentally induced wounds in mice (Grad, Cadoret & Paul, 1961), to accelerate the recovery of mice from anesthesia without physical contact (Watkins & Watkins, 1971; Watkins, Watkins, & Wells, 1973; Wells & Klein, 1972; Wells & Watkins, 1975), to speed the regeneration of salamander forelimbs (Wirth, Johnson, Harvath & MacGregor, 1992), to heal malaria in rats, remotely and retroactively (Snel & Van der Sijde, 1990-1991), and to facilitate the healing of surgically induced wounds in humans. (Wirth 1989, 1990, but see also the nonsignificant study of the effect of healing and prayer on diabetes mellitus by Wirth & Mitchell, 1994). 

Radin, Taft and Yount (2003) report a study on the influence of practitioners of Johrei, a Japanese spiritual healing practice, on the proliferation of cultured human brain cells (astrocytes).  Radin et al. report a significant increase in treated cells relative to control cells, although this difference was only significant on the third day of treatment.  They also found that the Johrei healers could influence the output of a quantum-based random event generator (REG).  The psychokinetic effect on the REG declined with distance, which the authors interpret as supporting the hypothesis that the healing effect involves some sort of radiation.

Bengston and  Krinsley (2000) report a significant difference between healers and skeptics as they attempted to inhibit the growth of transplanted breast cancer cells in mice.  However, this study was flawed in that the healers were allowed to place their hands just outside of the mice’s cages, which would allow the transmission of sensory cues (e.g., the movements of the hands of the healers might be gentler and less threatening that those of the skeptics).  Another flaw in this experiment is that the control group of mice were housed in a different city than the treated group; thus, the differences between the treated and control mice might have been due to differences in weather, pollution levels, or other factors.

A large number of studies have shown that the growth of plants may be accelerated when they are irrigated with water previously held by healers or when they are grown from seeds held by healers (Grad, 1963, 1964; MacDonald, Hickman & Dakin, 1977; Solfvin, 1982; Saklani, 1988a, 1988b, 1989, 1990, 1991,1992; Scofield & Hodges, 1991; and Roney-Dougal & Solfvin, 2004). There have also been claims of changes in the light absorption properties of samples of water held by healers, (Grad 1964, 1965; Dean 1983a, 1983b; Dean & Brame 1975; Grad & Dean, 1984; Schwartz, De Mattei, Brame & Spottiswoode, 1987; Saklani, 1988a, 1988b; Rein & McCraty, 1994: but see also Fenwick & Hopkins, 1986).  Healers have also been found to produce effects on the activity levels of enzymes (Smith, 1968, 1972; Edge, 1980b; Bunnel, 1999).  

Experiments have shown that even ordinary citizens may be able to influence biological systems at a distance. Ordinary subjects in such bio-PK experiments have been found to be capable of affecting the growth rates of fungal and bacterial cultures (Barry, 1968a, 1968b; Tedder & Monty, 1981), the mutation rates of bacterial genes (Nash, 1984b), the electrical activity of plants (Dolin, Davydov, Morozova & Shumov, 1993), the electrodermal and brainwave patterns of human subjects (Braud & Schlitz, 1983, 1989; Braud, Schlitz, Collins & Klitch, 1985; Dolin, Dymov & Khatchenkov, 1993; Radin, Taylor & Braud, 1993), the firing rate of individual neurons of the sea snail Aplysia (Baumann, Stewart & Roll, 1986), and the rate of hemolysis of red blood cells (Braud,1988, 1990; Braud, Davis & Wood, 1979), to name only a few of the effects that have been reported.  

To be sure, not all investigators who have looked for such effects have found them, but the success rate is rather substantial.  In a “meta-analysis” of 149 psychokinesis experiments using living organisms as targets, Braud, Schlitz and Schmidt (1990) found that 53 percent of them produced significant evidence of a psi effect.  As in any other area of research, the methodological quality of the studies is uneven.  While the procedures in many of the studies are quite sound, others suffer from various defects.  One common defect is that the person caring for or measuring the target organisms may not be blind as to which experimental group the organisms are in.  If the person watering a plant or placing a fungal colony in an incubator knows whether the plant or fungus is in the “healed group” or the control group, this may affect his treatment of the organism.  This was in fact a problem in some of the plant and fungus experiments (e.g., Nash, 1984b; Saklani, 1988a, 1988b).  Another defect occurs when the target and control organisms are not housed in the same areas or under comparable conditions, as was the case in some of the wound-healing experiments with mice (e.g., Grad, Cadoret & Paul, 1961), or when the healing and control procedures are carried out at different times or locations, as was the case in some of the mouse anesthesia experiments, some of the enzyme studies, and some of the human wound experiments (e.g., Watkins & Watkins, 1971; Rein, 1986; Wirth, 1989, 1990).  In such cases the target organisms or systems may simply be responding differently to different locations or times of day rather than to the treatments. A third defect occurs when the healer is allowed to be in close physical proximity to the patient or target organism, as the possibility then arises that any effects may be due to suggestion or to the comforting of an animal. 

One criticism that has been leveled against parapsychological experiments in general is that the results may be due to experimenter dishonesty.  Flamm (2004, 2005) raises such questions regarding the investigator Daniel Wirth.  Flamm notes that Wirth and his coworkers conducted a study in which infertile women who were prayed for in Christian prayer groups became pregnant at twice the rate of women in a control group (Cha, Wirth, & Lobo, 2001).  It should also be noted that Wirth’s work has been widely cited above in connection with other areas of psychic healing.  Flamm notes that Wirth has received a five-year prison sentence on thirty counts of fraud and that he often assumed false identities in connection with his embezzlement schemes.  Joseph Horvath, who collaborated with Wirth on some of his psychic healing studies (e.g., Wirth, Johnson, Horvath & MacGregor, 1992), has also gone to prison for embezzlement and the use of false identities.  Among their crimes, Wirth and Horvath were convicted of bilking the Aldelphia Communications Corporation out of $2.1 million by infiltrating the company and then having it pay for unauthorized consulting work.  Flamm also notes that Horvath posed as a medical doctor when performing biopsies on human subjects and that Dr. Rogerio Lobo, who was listed as a coauthor on the study regarding the effect of prayers on infertility in fact had no involvement in the study.

Nonetheless, when the work of Wirth and his collaborators is removed from consideration, there remains a large number of seemingly methodologically sound studies that appear to show that humans are capable of affecting biological systems at a distance, and that therefore there may well be reason to believe that there could be some validity to the claims of laying-on-of-hands or remote healing.  The reason this evidence is largely ignored by the medical and scientific community is probably related to scientific community’s general rejection of psi research; the data just do not fit into established theories.  On the other hand, while there may be prejudice against this research, any person seeking treatment should understand that the magnitude of the healing effects found in these studies tends to be far less than the effects produced by orthodox medical treatment, and they are also much less reliable.

Summary of healing studies. In conclusion, there is not much solid evidence for the existence of paranormal effects in the areas of faith healing, psychic diagnosis, or psychic surgery. With regard to the techniques of laying-on-of-hands and remote healing, there are hints from the existing experimental evidence that some sort of paranormal effect could be involved in these techniques.

Psi Phenomena in Nonwestern Cultures

Several anthropologically-oriented investigators have explored beliefs about and practices relating to psi phenomena in cultures markedly different from our modern Western civilization. These studies may be broken into roughly two types: (a) those that merely seek to describe such practices and beliefs, and (b) those that seek to evaluate the hypothesis that psi phenomena are actually involved in such practices.

With regard to studies of the first type, Shiels (1978) reported the results of a survey indicating a widespread belief in out-of-body experiences (OBEs), in which the subject’s conscious mind seems to travel to locations outside of the physical body, among nonwestern or “primitive” cultures.  Haynes (1984) notes that witches’ brews and ointments frequently contain hallucinogenic chemicals that could produce sensations of flying and hence precipitate OBEs.  Magical or psi-like powers are frequently attributed to shamans or medicine men in “primitive” cultures. The belief of the Australian aborigines that their “clever men” may project themselves at will has already been discussed.  

Reichbart (1976) describes how Navajo hand tremblers are thought to be able to find lost objects and to diagnose the causes of illnesses. In a general essay on shamanic practices, Reichbart (1978) notes that the following powers have been attributed to shamans: (a) the ability to direct the movements of game animals, (b) healing abilities, (c) the ability to find lost objects, and (d) the ability to predict and control the weather.  He notes that shamans frequently do rely on sleight-of-hand techniques and use normally acquired information in their practices.  He suggests that the use of such fraudulent practices may facilitate the occurrence of actual psi phenomena, and he compares it to the technique developed by Kenneth Bacheldor and employed by Brookes-Smith (1973) of using fraudulently-produced table movements to create an atmosphere in which paranormally produced table movements may be more likely to occur in a seance situation. (Unfortunately, there is little in the way of hard evidence that any of the table movements produced using Brookes-Smith’s technique were in fact genuinely paranormal.)  

Winkelman (1983) has traced several similarities between techniques used in experimental parapsychology to elicit psi and shamanic practices.  Like parapsychologists, shamans may use altered states of consciousness and visualization techniques to facilitate psi.  Shamans and other nonwestern diviners may use random processes, such as tossing coins when using the I Ching, as a part of their divination practices.  It is possible that such random devices could be susceptible to psychokinetic influence by the shaman, allowing the production of meaningful messages.  (On the other hand, we have of course already seen the lack of effectiveness of such techniques when subjected to experimental test.)

Studies of the second type go beyond mere description and attempt to evaluate the paranormality of the purported effects.  Some investigations are essentially anecdotal in nature.  McKee (1982) describes a case involving voodoo-like effects on the wife of the manager of a Ford agency in Swaziland.  This woman had been experiencing migraine headaches for a period of time before a clay effigy was discovered hidden in an unused cupboard.  The woman had told her maid that she could work for her if she were sick.  Her headaches went away after a ritual in which the effigy was destroyed and prayers were said.  This cure could of course, like the cases of voodoo death discussed previously, be purely psychosomatic in nature and no more paranormal than the usual placebo effect.   

Some experimental investigations of the psi powers of nonwestern shamans and healers have been reported.  In an investigation of the psychokinetic powers of the practitioners of an Afro-Brazilian healing cult, Giesler (1985) found that such practitioners were more successful in an experimental test of their PK abilities than were control subjects.  Their scoring was facilitated when a cult-relevant form of feedback (the display of a deity figure) was used to signal success in the PK task.  The significance of Giesler’s results may, however, be questioned due to the large number of statistical tests he performed on his data.  Saklani (1988a, 1988b) found Himalayan shamans to be successful in using PK or “healing energies” to accelerate the growth of plants.  In this context, it would be good to keep in mind the previously discussed negative verdict on psychic surgery.   

Firewalking is a technique practiced by people in diverse cultures, ranging from fakirs in India to (in fairly recent times) account executives in California.  The ability to walk on fire is often taken as an indication of the firewalker’s mental discipline, spiritual development or faith.  In back-to-back articles in The Skeptical Inquirer, Dennett (1985) and Leikind and William McCarthy (1985) observe that many of the materials used in such firewalking escapades, such as wood, coal and volcanic pumice, are noted for their low heat capacity or poor thermal conductivity.  Leikind and McCarthy also suggest that the “leidenfrost effect” may protect the feet of firewalkers.  Water vapor is a poor conductor of heat, and sweat from the feet of the firewalker may form an insulating layer, or leidenfrost, protecting the feet from burning.  Therefore, there may be nothing paranormal about a person’s ability to walk on fire for reasonably short distances at a fast enough pace.  Thus, a high degree of spiritual development may not be a prerequisite for successful firewalking, and so Hollywood celebrities and other “New Age” types need not balk at treading the coals.

Probably the most outlandish anecdotal case in the professional literature is David Read Barker’s claim to have witnessed a possible instance of weather control by a Tibetan shaman (Barker, 1979).  This shaman was commissioned by the Dalai Lama to perform a rite designed to stop a huge storm long enough for a mourning ceremony to take place.  The storm was reduced to an area of cold fog within a radius of 150 meters of the site of the ceremony, although the rain continued to pour elsewhere.  Of course, this is an isolated observation, so a coincidence explanation cannot be ruled out.

While anthropological investigations have yielded tantalizing hints of dramatic phenomena such as Barker’s anecdotal report of weather-engineering, such studies have been sparse indeed.  A more systematic effort may be needed to sort the wheat from the chaff in this area.  Such an effort would of course cost money, and, given the present state of funding in parapsychology, it is not likely to happen soon.


There are a wide variety of truly strange phenomena that are sometimes linked, albeit tangentially, with phenomena that form the subject matter of more “orthodox” parapsychology.  These bizarre occurrences are sometimes designated “Forteana,” in honor of the early twentieth century paradoxer Charles Hoy Fort, who amassed a large catalogue of anomalies that seem to fly in the face of modern science.  Forteana include such diverse subjects as UFOs, sightings of Bigfoot and the Loch Ness monster, weeping statues, the Bermuda triangle, and spontaneous human combustion.  While none of these topics have been given extensive consideration by mainstream parapsychologists, relationships between these phenomena and more typical psi phenomena have been drawn by several “fringe” writers.  Therefore, for the sake of completeness (as well as the reader’s entertainment), a very brief discussion of Forteana is given in the paragraphs to follow, with an emphasis on the connections that have been alleged to exist between Forteana and the psi phenomena more typically studied by parapsychologists.

In cases of spontaneous human combustion, people are alleged to burst into flames for no apparent reason, with their bodies being more or less completely incinerated.  While this might seem to be intimately related to the spontaneous ignition of fires that occur in some poltergeist cases, parapsychologists have shown remarkably little interest in spontaneous human combustion.  A skeptical explanation of this phenomenon has been provided by Nickell and Fischer (1987), writing in the pages of The Skeptical Inquirer.  In their view, many cases of ostensible spontaneous combustion death may be explained in terms of careless cigarette smoking by intoxicated persons of high body fat content.  The body fat and the alcohol provide the fuel for the fire, with the body fat liquefying in what the authors colorfully term “the human candle effect.”   

Paranormal phenomena are frequently linked with Christian saints and holy men (and women) of other religions; indeed, such phenomena often constitute the miracles prerequisite to the canonization of such saints.  Among the psi phenomena that have been ascribed to Christian saints are the materialization of food, the ability to prophesy, bilocation, levitation (as in the famous cases of St. Joseph of Copertino and St. Teresa of Avila, both of whom were reported to frequently ascend into the air in fits of religious ecstasy), and immunity from the damaging effects of fire (see Rogo, 1981 and White, 1982, for a review of such phenomena).  Schwarz (1980) has described cases of fire immunity, fire handling and apparent immunity from snakebites among Pentacostal worshippers, and Alvarado (1987) notes that luminous auras have often been reported around both saints and mediums.  

Alvarado (1983) has also reported on a case in which faces kept appearing on a kitchen floor as well as on a mirror and on the hearth of a house. When the offending spot on the kitchen floor was cut out, bones were discovered under the site of the face.  Not to be forgotten in this context is image of the Virgin Mary that recently manifested in a grilled cheese sandwich that fetched a price of $28,000 in an eBay auction.  However, the human brain is hard-wired to detect human faces, and it seems that, whenever anything remotely resembling a human face appears, Marian enthusiasts interpret it as an image of the Blessed Virgin.  In recounting the tale of the grilled cheese sandwich icon, Nickell (2005b) notes that the Virgin’s likeness has also appeared on a cinnamon bun in a coffee chop and that Jesus has appeared in a tortilla as well as in a giant forkful of spaghetti.  Lest it be thought that divine appearances are restricted to food items, it should be noted that the Blessed Virgin has also recently manifested Herself in a salt stain on a highway overpass in Chicago (Associated Press, April 20, 2005). 

The list goes on and on, and encompasses bleeding statues, sightings of the Virgin Mary, UFOs, Sasquatch, crop circles and cattle mutilations.  It would take us too far afield to give a comprehensive review of such fields as ufology and cryptozoology here.  Readers interested in such phenomena are invited to consult such specialty journals as the Journal of Scientific Exploration and The Skeptical Inquirer. 

D. Scott Rogo (1977) hypothesized that many strange, seeming external and physically objective phenomena such as flying saucers and Bigfoot are really materialization phenomena or psychic projections that are produced by the minds of the observers themselves.  As such, these would be analogous to the “thought forms” that are alleged to be projected by Tibetan shamans, as described by Alexandra David-Neel (1971). Because there is little in the way of scientifically rigorous evidence for the existence of materialization phenomena and because many of the cases that Rogo cited in support of his theory are of dubious credibility, the parapsychological community has been slow to embrace his theory.

General Summary of Field Investigations

The evidence discussed in this chapter has been largely of an anecdotal nature. A determined skeptic might be inclined to dismiss all of it on the basis of coincidence, unconscious inference, memory distortion, delusions, hallucinations and outright fraud.  It is largely because of these counterexplanations that parapsychologists have turned to experimental investigations as the primary means of establishing the existence of psi phenomena and investigating their modus operandi.  These investigations form the subject of the next chapter. It should be noted, however, that these experimental studies have themselves been subject to repeated attacks by skeptics on the basis of methodological errors, lack of repeatability, and possible experimenter fraud.  Sometimes spontaneous case material may be more convincing than an array of experiments.  I have talked to several skeptics who, while dismissing experimental investigations, were left with a nagging feeling that psi might be real after all due to their own personal psi experiences or those of their acquaintances.

A summary dismissal of the evidence from spontaneous cases as nonrigorous and hence unworthy of serious consideration is not appropriate.  Not only may spontaneous cases provide unique insights into the operation of psi in naturalistic settings, which may not be obtainable from contrived and artificial experimental situations, but they may provide important clues as to possible productive lines of experimental investigation.  Also, many skeptical counterexplanations of spontaneous cases are quite implausible.  Thus, spontaneous cases form an important body of evidence for psi in their own right, and supplement the evidence obtained by experimental parapsychologists.  A past president of the Parapsychological Association, Rhea White, has even gone so far as to urge the abandonment of the experimental approach in psi research in favor of the study of spontaneous cases (White, 1985, 1990).  She has contended that reliance on statistical and laboratory methods may lead to a suppression of awareness of clues to the nature of psi arising from spontaneous experiences and informal practices, and she suggests adopting a “depth psychology” approach to the investigation of parapsychological phenomena. She has further contended that sounder data have arisen from surveys of spontaneous experiences than from unreliable laboratory effects.  In all probability, however, it will take evidence of both types to convince a skeptical scientific community of the existence of psi. A total abandonment of the experimental approach would probably disqualify parapsychology from any claim to be a real science in the eyes of the scientific establishment.  Experimental approaches must be an integral part of any science of parapsychology.  It is to an examination of such laboratory studies that we now turn.



4. The Evidence for Psi: Experimental Studies

 As noted in the last chapter, most parapsychologists have adopted the view that spontaneous cases cannot provide a “clean proof” of the existence of psi due to the various possible skeptical explanations of these cases, such as those invoking coincidence, delusion, unconscious inference and fraud.  Therefore, they have turned to experimental approaches to establish the reality of psi effects.  In the early days of parapsychology, such experiments typically involved attempts by human subjects to use their powers of extrasensory perception to discern the identity of a playing card hidden from their view or to use their psychokinetic abilities to influence the fall of mechanically thrown dice.  When a subject is guessing a randomly selected card held in a separate room, the problems of sensory cues and unconscious inference are presumably removed.  If contemporaneous records of the experiments are made, one need not rely on the fallible memory (or deceiving testimony) of the people involved, save of course for the experimenters themselves.  Thus, the problems of memory distortion or fraudulent testimony on the part of informants in spontaneous cases are likewise eliminated when the experimental approach is adopted.

Perhaps the chief benefit of the experimental approach is its ability to deal with the objection that apparent cases of psi are simply due to coincidence. For instance, suppose an experiment is run in which a subject tries to guess in advance the outcomes of a series of tosses of an unbiased coin. If the subject guesses the outcomes of four tosses, his probability of getting them all right by chance may be easily computed. If a coin is tossed four times, one of the following events must occur:


















(Here HHTH, for instance, denotes the event in which the coin comes up heads on the first, second and fourth tosses, while the third toss comes up tails.)  As these events are all equally likely, the probability that the toss outcomes correspond exactly to the subject’s sequence of guesses is 1 in 16.  In other words, the subject would be expected to obtain perfect success through sheer luck in about one out of every sixteen experiments.  Similarly, if a subject guesses twenty-five flips of a coin and gets twenty of them right, standard statistical formulas may be applied to determine that the probability of guessing twenty or more flips correctly by chance is approximately .002.  In other words, one would expect this level of success to occur in only two out of every thousand experiments by chance.  As it would be unlikely that this level of success could be achieved through sheer luck (that is, in the absence of ESP), one would take the step of rejecting the “null hypothesis” (that the results can be ascribed to chance) and state that the results are significant at the .002 level, meaning that the probability of attaining such an extreme score by chance would be less than .002 in the absence of ESP.  Similarly, if a person attempts to guess the order of the cards in a well-shuffled and hidden deck of ESP cards and guesses 13 of the cards correctly (as opposed to the five she would be expected to get right on the average by chance), the mathematical theory of probability can be invoked to show that this would happen in fewer than 1 in 10,000 such experiments by chance.  We would conclude that it is very unlikely that we would have obtained such a result by chance unless we were to run thousands of such experiments.

The philosopher Francis Bacon was perhaps the first on record to suggest that psi phenomena could be investigated through the statistical analysis of card-guessing and dice-throwing experiments (Bell, 1956).  Charles Richet of France (1884, 1888) was the first to initiate anything approaching an actual research program in this area, using card-guessing as a technique for investigating ESP.  In the early part of the twentieth century, experimental studies of ESP involving the guessing of cards were performed by Leonard Troland and George Estabrooks at Harvard University and J. E. Coover at Stanford University (Troland, 1917; Coover, 1917; Estabrooks, 1927).  Estabrooks’ very successful experiment was conducted while completing his doctorate under William McDougall, a prominent psychologist who had an interest in psychical research.

In 1927, McDougall moved to Duke University to assume the chairmanship of the psychology department. He was followed soon thereafter by an enthusiastic young psychical researcher, J. B. Rhine, and his wife, Louisa. During the academic year 1929-1930, Rhine began his program of experimental research on psi phenomena. This program eventually evolved into the sustained and continuous research tradition that has become known as experimental parapsychology.  For this reason, Rhine is usually regarded as the founder of the field of parapsychology (in the sense of the experimental study of psi phenomena). Rhine in fact was responsible for the adoption of the name “parapsychology” to describe his field of inquiry, although it should be noted that Max Dessoir (1889) in Germany was the first to use the term “parapsychologie” to describe the investigation of the “border” region between normal and abnormal psychological states. Rhine can, however, lay sole claim to coining the term “extrasensory perception,” or ESP, to describe the receptive form of psi (as opposed to psychokinesis, the alleged ability of mind to influence matter directly and without involvement of the motor apparatus of the body).

Rhine’s initial methods for investigating ESP relied heavily on the standard “ESP cards,” which were designed for Rhine by the Duke perceptual psychologist Karl Zener.  (This deck was known for a long time as the “Zener deck,” somewhat to the consternation of Zener, who later abandoned parapsychological research for work in more mainstream and less controversial areas of psychology.)  The ESP deck consists of 25 cards, with five cards representing each of the following five symbols: circle, star, cross, square and wavy lines.  When a subject guesses the order of the cards in a well-shuffled ESP deck, he has a one-fifth chance of guessing any particular card correctly, and it can be shown mathematically that the average score he would expect to achieve by chance is five correct guesses.

In 1934, at the suggestion of a young gambler, Rhine began to investigate psychokinesis (PK), using dice as target objects.  Initially, Rhine investigated the ability of human subjects to influence dice to roll in such a way that a given “target” face would come up. Later, other investigators had subjects attempt to influence the direction or speed of mechanically thrown dice so that they come to rest at specific target locations. Such tests became known as “placement tests.” Because of the controversy surrounding his ESP results, Rhine withheld publication of his PK research until 1943.

In the modern era, the targets of psychokinetic influence have expanded to include living organisms, red blood cells, thermistors, and quantum-mechanically based random event generators (REGs).  REGs have also been used to generate ESP targets.  In ESP research, there has been a move in the direction away from forced-choice experiments (in which the subject’s response on each trial is restricted to a finite set of specified alternatives, as in guessing a deck of ESP cards) and toward free-response experiments, in which a subject is free to describe his impression of the target in any manner he chooses.  

A free-response methodology is employed in modern ganzfeld experiments, in which a subject is typically seated in a comfortable chair with ping-pong balls placed over his eyes to produce a uniform visual field.  Frequently, white or “pink” noise played in the subject’s ears to produce a homogeneous form of auditory stimulation as well.  

The subject may then try to describe a target picture that is being viewed by a human sender or agent, this target having been randomly selected from a target pool consisting of, say, four potential target pictures.  The subject or an outside judge then ranks the pictures in the target pool against the subject’s descriptions.  Obviously, given the random nature of the target selection, the probability that the subject’s description will be matched against the correct target by chance is one-fourth.  

Other examples of free-response experiments include remote viewing studies, in which a subject attempts to describe the location to which a human sender has been sent, and dream studies, in which a subject’s dream reports are matched against, say, art prints viewed by a human sender attempting to influence the subject’s dream.

Forced-choice Experiments

Perhaps the foremost forced-choice ESP experiment performed in the heyday of the card-guessing era of Rhine’s early research group at Duke University was the Pearce-Pratt series conducted on the Duke campus during the 1933-1934 academic year (Rhine & Pratt, 1954).  In this experiment, the subject, a divinity student named Hubert Pearce, attempted to guess the identity of cards held in a separate building by J. G. Pratt, a graduate student in psychology.  In each session, the men would synchronize their watches, and then Pearce would leave for a cubicle in the stacks of the library.  Pratt then shuffled a deck of ESP cards and placed one card face down each minute on a book on a table in his building, which was either the Physics Building (100 yards distant from the library) or the Medical Building (250 yards distant).  Pearce attempted to guess the identity of the card located on the book at the specified time. Two decks were guessed per session. In all, 1850 cards were guessed, and Pearce averaged 7.54 cards guessed correctly per deck, where 5 would be expected by chance. These results were significant at the p < 10-22 level, meaning that this level of success would occur by chance fewer than once in 10 sextillion such experiments.  Clearly chance coincidence cannot account for these results, and they have been taken as strong evidence of ESP.

A more modern form of forced-choice experiment was pioneered by physicist Helmut Schmidt (1969) in his study of the precognition of radioactive decay, a quantum process that is in principle unpredictable under modern theories of physics. Schmidt’s study relied on a type of quantum-mechanically based REG that has since become known as a “Schmidt machine” and is now a widely-used and basic tool in parapsychological research.  With Schmidt’s original machine, the subject was confronted with an array of four differently colored light bulbs.  The subject’s task was to guess which bulb on the display was going to be the next to light up.  The subject signaled his or her guess by pushing a button in front of the chosen bulb.  During this process, an electronic counter was constantly cycling through the values 1, 2, 3, 4, 1, 2, 3, 4, 1, 2, 3, 4… at the rate of a million steps a second. After the subject pressed a button indicating his or her guess, the counter stopped when a Geiger counter detected a decay electron emitted from a sample of strontium 90 and the corresponding lamp was lit.  The subject’s task could thus be construed as one of predicting the time of future radioactive decay of a strontium 90 atom to within an accuracy of a millionth of a second.  (However, more plausibly from a psychological and sensory-motor point of view, the subjects were simply foreseeing which lamp would be lit.) The subjects’ guesses and the lamps actually lit were automatically recorded on counters and punch tape, eliminating the possibility of directional errors by human recorders. Extensive randomness tests were run on the REG to ensure that its output was indeed random.  In Schmidt’s first experiment, three subjects made a total of 63,066 guesses and scored 691.5 more hits than they would have been expected to by chance.  This level of success could be achieved through sheer luck in only two out of every billion such experiments.  In a confirmation study, Schmidt had the subjects attempt to achieve high scores in some prespecified trials and low scores in others.  20,000 trials were run, and the subjects obtained 401 more hits (in the prespecified direction) than they would have been expected to by chance. Results this good would occur by chance only once in 10 billion such experiments.   

Free-Response Experiments

In free-response experiments, the target is generally not chosen from a small pool of targets known to the subject, but instead may be drawn from a small pool of targets that is unknown to the subject at the time of the trial.  Much more rarely, the target may be created uniquely for each trial.  The subject in turn does not simply select a guess corresponding to one of a fixed number of alternatives, but rather describes her impressions of the target, which may be in the form of dreams, visual imagery, or a free-association monologue.  The subject typically uses verbal descriptions or drawings to communicate these impressions.

Some of the earliest free-response experiments involved the telepathic transmission of drawings (e.g., Sinclair, 1930/1962; Warcollier, 1948/1963).  In these studies, the sender, or agent, generally constructed a drawing and the percipient attempted to draw a picture corresponding to the sketch made by the agent.  In these early studies, some very striking correspondences were obtained, even when the sender and the percipient were located on opposite sides of the Atlantic Ocean.  However, as the targets were not selected randomly from a fixed set of alternatives, statistical evaluation of these correspondences proved difficult and a quantitative estimate of the probability that these similarities between the agent’s drawings and the percipient’s impressions would arise by chance could not be obtained, despite the subjectively striking nature of these correspondences.

The most commonly used techniques in modern free-response experiments are the ganzfeld and remote-viewing procedures.  A highly successful series of remote-viewing trials was conducted in the late 1970s by the team of Targ and Puthoff at Stanford Research Institute (Puthoff & Targ, 1979; Targ & Puthoff, 1977; Targ, Puthoff & May, 1979).  To give the reader the flavor of the remote-viewing procedure, a single trial from a five-trial long-distance series will be described.  Unlike most of Targ and Puthoff’s trials, the target was not chosen randomly but rather was selected by a skeptical scientist.  The scientist then took the remote-viewing team to the target site, which was a series of underground chambers in Ohio Caverns in Springfield, Ohio, which were filled with stalagmites and stalactites.  The subject remained behind in New York City and was told only that the remote-viewing team was located somewhere between New York City and California.  After the remote-viewing team had spent 45 minutes touring the caverns, the skeptical scientist then called the subject in New York, whereupon a transcript of the subject’s impression of the target area was read to him. The opening passage of the transcript was as follows:

1:50 PM before starting—Flat semiindustrial countryside with mountain range in background and something to do with underground caves or mines or deep shafts—half manmade, half natural—some electric humming going on—throbbing, inner throbbing. Nuclear or some very far out and possibly secret installation—corridor—mazes of them—whole underground city almost—Don’t like it at all—long for outdoors and nature. 2:00 PM—[Experimenters] R and H walking along sunny road—entering into arborlike shaft—again looks like man helped nature—vines (wisteria) growing in arch at entrance like to a wine cellar—leading into underground world. Darker earth-smelling cool moist passage with something grey and of interest on the left of them—musty—sudden change to bank of elevators—a very manmade [sic] steel wall—and shaft-like inserted silo going below earth—brightly lit (Targ, Puthoff & May, 1979, p. 88).

The above correspondence is of course quite impressive. But it is important that targets in free-response experiments be chosen randomly (as they were in most of Targ and Puthoff’s research).  For instance, a depressing global event (or increasing sunspot activity, etc.) may have caused both the skeptical scientist and the percipient in this experiment to be in a gloomy mood, and that may account for both the scientist’s selection of a dark underground cave as a target area and for the percipient’s descriptions.

In the early 1970s, Montague Ullman and Stanley Krippner conducted an experimental study of “dream telepathy” at the New York Maimonides Medical Center (Ullman, Krippner & Vaughn, 1973).  This research employed a fully-equipped sleep laboratory and was designed to investigate the possibility that a subject’s dreams could incorporate elements of an art print chosen as an ESP target.  The subject went to sleep in the laboratory, with the usual EEG electrodes affixed to his head.  He was then awakened toward the end of each rapid eye movement (REM) period, which is known to be associated with dreaming, and asked to give a dream report.  Several such reports would be elicited from a given subject in a typical night.  The art print to serve as the ESP target was randomly chosen from a set of possible targets.  A person who served as sender or “agent” then attempted to “send” the picture to the sleeping subject, so that the latter might incorporate the target material into his or her dream. Usually, one art print served as the target for an entire night.  After the subject’s sleep period was concluded, the subject’s dream reports were compared to the target as well as to a set of control art prints, which served as foils.  The pictures were then ranked as to degree of correspondence with the dream reports, both by the subject and by outside judges.  In several series, the foil pictures consisted of the remaining targets in a small target pool from which the actual target was chosen.  Some subjects obtained highly successful results.  For instance, a woman named Felicia Parise obtained 34 “direct hits” (meaning that the target picture was rated first among the pictures in an eight-target pool in terms of correspondence with the subject’s dream) out of 66 trials, as determined by her own ratings of the targets.  Only 8.25 direct hits would be expected by chance, so this is a clearly significant result.  Strangely enough, the independent judges gave Ms. Parise only nine direct hits (about what would be expected by chance).  Another subject, Dr. Robert van de Castle, himself a dream researcher, spent eight nights in the laboratory as a subject and scored a “hit” (target print ranked in the top half of the eight-target pool) on each night by his own evaluations.  The independent judges gave him only six hits, but five of these were direct hits, where only one direct hit would be expected by chance.  Many other subjects were less successful.

Sometimes rather striking correspondences between the target print and the subject’s dream were obtained.  For instance, on one night the art print chosen as target was Goya’s “The Duelers,” which portrays two Spaniards engaged in a duel with swords.  One of the participants has succeeded in making a thrust into the other’s abdomen.  The first dream report of the subject, Dr. Robyn Posin, a psychologist, was as follows:

[I was] in the office of a man who is sort of waiting for this woman to arrive. He’s actually … talking about her in the sense that the venom and anger that I experience in him is reserved for her … And he has this thing that’s like a bullwhip … and he hits the wall with the whip and makes a crack … and then thinks of a woman. There was something very impotent about this man’s rage … It wasn’t a bullwhip that he had, it was really a cat-o’-nine tails … It had its origins … in Spain … It was a very frightening experience (Ullman, Krippner & Vaughn, 1973, p. 131).

The researchers go on to report that

In her seventh dream, she was at a Black Muslim rally. “They were really raging, and all of a sudden some doors from an auditorium opened and out came Elijah Mohammed and a bunch of his followers … He had on this huge flaming torch with which to set some more stuff on fire, and I got very scared.” Her associations to this were “It was like a real chaos scene … the terrorism, that same kind of lack of control, I guess, that seemed to me to be anger and hostility and acting out in it … It’s some sort of conflagration, either symbolically or realistically … something rather violent” (Ullman, Krippner & Vaughn, 1973, p. 131).

Subconscious Psi 

The above experimental procedures are aimed at detecting the conscious use of psi.  In the past few years, there have been an increasing number of experimental investigations of the unconscious or subconscious detection of psi signals.  For instance, McDonough, Don and Warren (2002) ran an experiment in which the subject attempted to guess which of four playing cards sequentially presented on a video monitor had been selected as the ESP target.  They found a greater amplitude of slow wave brain potential 150-500 milliseconds after the target card was presented compared to that following the control cards.

Similarly, Satori, Massaccesi, Martinelli, and Tressoldi (2004) found subjects’ heart rates were accelerated when the ESP target picture was presented compared to the heart rates when the nontarget pictures were presented.  This effect occurred even though the subjects’ scores on the conscious ESP guessing task did not differ significantly from chance. 

Radin (1997b, 2003, 2004) has carried out a series of studies in which he found that subject’s heart rates and electrodermal activity (a measure of stress, anxiety or excitement) increased prior to the presentation of emotional pictures when compared to the same time periods prior to the presentation of control pictures.  Across all four or Radin’s studies, this effect was statistically significant at the .001 level.  Radin terms this effect “presentiment.”  It would appear to be a case of subconscious precognition, manifested in physiological activity rather than in the subjects’ consciousnesses.   Radin (1997a) attributes Libet’s finding that a widespread buildup in brain potential precedes the conscious experience of a voluntary decision to initiate a finger movement (Libet, 1991a) as a presentiment “presponse” (as opposed to “response”) of the brain’s own decision-making.

In a similar vein, May and Spottiswoode have found an increased startle response (as measured by skin conductance) in three-second epochs (time periods) prior to a startling stimulus (a blast of white noise) relative to control trials in which no startling stimulus was presented (May & Spottiswoode, 2003; Spottiswoode & May, 2003).

Darryl Bem, a prominent social psychologist, has devoted much of the past ten years of his career to parapsychological research.  Bem (2003) has recently conducted an experiment in which he presented pairs of positively-valenced (i.e., pleasant) pictures and pairs of negatively-valenced (unpleasant) pictures to human subjects.  He asked the subjects which picture of the pair they preferred.  Then one picture from each pair was chosen as the target and these targets were then subliminally presented to the subject.   Bem found that subjects presented with a pair of positively-valenced pictures preferred the picture that would not be chosen as the target and that subjects presented with pairs of negatively-valenced pictures preferred the picture that would be chosen as the target.  Bem attributes his results to “precognitive habituation,” postulating that the repeated subliminal exposure in the future diminished the subject’s affective responses to the targets in the present (i.e., both the positive and negative targets became more neutral in comparison to the nontarget pictures).  In short, repeated subliminal exposures of the picture in the future diminished the subject’s emotional/aesthetic responses in the present.  Bem also found a precognitive habituation effect for targets that were supraliminally presented to the subject (i.e., the subjects could perceive the pictures consciously), but only for negatively-valenced pictures.

As with most lines of parapsychological research, these results have not been universally replicable.  For instance, Broughton (2004) failed to replicate Radin’s “presentiment studies.”  Broughton also reported a very poor test-retest reliability score, indicating that his subjects failed to manifest a consistent psi effect.   Similarly, Sarra, Child and Smith (2004) failed to replicate Bem’s “precognitive habituation” effect using pictures of spiders as the negatively valenced targets.

PK Tests - “Micro-PK”

PK tests may be divided into roughly two types: “micro-PK” tests, in which the evidence for PK is primarily based on deviations from statistical distributions expected by chance (such as those governing the fall of dice) and “macro-PK” tests, in which the subject attempts to create a macrophysical change in the target object (such as by bending a spoon).

In the early days of parapsychology, dice typically served as the target objects in micro-PK experiments. In the modern era, quantum-mechanically based random event generators (REGs) and living systems have been the most frequently used target objects. 

In one typical experiment involving animals as subjects, Schmidt (1970) enclosed his pet cat in a cold shack.  In the shack was a 200-watt lamp, which served as a source of heat for the cat. Once each second, a quantum-mechanically based REG of the type described previously sent either an “on” or “off” signal to the lamp.  The REG was designed in such a way that the probability of an “on” signal was 50 percent.  Thus, the cat could obtain more heat by using its psychokinetic abilities to influence the REG to output more “on” signals than would be expected by chance.  In fact, in 9000 trials, 4,615 “on” signals were generated, indicating that the cat may have used its PK to increase the probability of an “on” signal from 50 percent to 51.2 percent, admittedly a very slight increase, but one which would occur by chance in only eight of a thousand such experiments. To check the randomness of the generator, Schmidt ran the REG over a period of 24 nights without the cat in the shack and found no departures from chance levels in a total of 691,200 signals generated.

In a similar experiment Peoc’h (1995) placed a robot mother whose ambulations were determined by the output of an REG in the vicinity of a group of young chicks.  The chicks were able to influence the output of the REG in such a way that the robot mother spent more time in close proximity to the chicks than would be expected by chance.  

Some micro-PK experiments are designed to detect a psychokinetic influence on living organisms.  For instance, Braud (1979) conducted a study in which human subjects attempted to influence the spatial orientation of a knife fish (Gymnotus carapo). The fish generates its own electrical field, which Braud monitored through two parallel copper plates placed in the fish’s tank.  When the fish swam parallel to the plates, a weak signal was recorded; the signal became stronger as the fish rotated its position to become perpendicular to the plates. The human subject’s task was to increase the strength of these signals during certain time periods designated as conformance epochs.  The strength of this signal was then compared with that generated in other time periods that served as controls. The signal was found to be stronger during the conformance epochs than during the control epochs, indicating that the subjects were successful in influencing the fish to adopt an orientation perpendicular to the plates.

In recent years, there has been a flurry of research reports relating to the effects of global consciousness on the output of REGs.  Specifically, it is asserted that events that produce a state of widespread excitement through the world (or smaller region), resulting in a coherent state of consciousness involving many individuals, are associated with the anomalous behavior of REGs.  One research initiative to study this phenomenon is called the Global Consciousness Project (GCP) and involves the continuous monitoring several REGs paced at different locations around  the world.

Radin (2002) reported that the GCP REGs showed a high degree of correlation in their behavior on September 11, 2001 (the day of the terrorist attack on the World Trade Center) as well as on other days involving major news events over a 250 day-period.  Similarly, Nelson (2002) reports that the behavior REGs at 40 host sites became more correlated with one another at the time of the September 11 attack, with this effect being statistically significant at the 10-7 level.  He notes that some global events are accompanied by the anomalous behavior of REGs, while others are not (e.g., widespread flooding in Nicaragua resulting from the collapse of the Casaitas volcano).  It should, however, be noted that Scargle (2002) has criticized both Radin and Nelson for reporting exploratory analyses as if they were preplanned and for “lying with statistics” by presenting misleading graphs. 

Hirukawa and Ishikawa (2002) report evidence of anomalous deviations in the output of an REG toward the end of the Aomori-Nebuta summer festival in Japan.

Experiments on the effects of global consciousness on the behavior of REGs in fact predate the September 11, 2001 tragedy.   Radin, Rebman and Mackwe (1996) report evidence for increased variance in the output of an REG during times of high group coherence in a Breathwork workshop, but no increased variance during times of low group coherence.  Radin et al. also report a correlation in the outputs of two REGs separated by 12 miles during the first half of the broadcast of the 67th annual Academy Awards.  This correlation declined in the second half of the broadcast, as did the television audience, and the strength of the correlation was significantly related to the decline in the size of the television audience.

Bierman (1996) found an increased variance in the output of an REG during time periods in which disturbances occurred in a poltergeist case in the Netherlands.  He also reports deviations in the output of an REG during the time of a soccer match between the Dutch and Italian teams.  The REG’s behavior returned to normal after the winning score by the Dutch team with two minutes left in the game.

Nelson, Bradish, Dobyns, Dunne and Jahn (1996) report significant deviations in the output of an REG during periods of high attention, intellectual cohesiveness, and shared emotions of a discussion group.  In a review of 61 field REG experiments, Nelson, Jahn, Dunne, Dobyns and Bradish (1998) report highly significant deviations from chance expectation in REG output during intense emotional events during small group interactions, but no such deviations during times of less emotional events.  In a recent summary of this line of research, Jahn and Dunne (2005) state that in general, they have found high deviations from the distribution of REG outputs expected by chance at times of highly cohesive events producing “resonance,” but low deviations from chance during time of more “mundane” events. 

Of course, it is difficult to see why a coherent state of group consciousness should have an effect on the behavior of an REG that is otherwise not connected to the group.  As Palmer (1997) points out, the success of these “field REG” experiments is more likely due to psi influence by the experimenter, who has a vested interest in the experiment’s outcome than to psi influence by the group members, who are generally not focusing on, and in many instances are unaware of, the REG.   

PK Tests - “Macro-PK”

The subject of macro-PK is much more problematic. Macro-PK, which may involve the bending of metal specimens, the ostensibly paranormal production of images on photographic film, or the movement of small objects across the surface of a table, usually involves special subjects having the status of semiprofessional psychics.  Because the psychic himself to a large extent determines the nature of the phenomena he may produce and the conditions under which he feels comfortable in producing them, the investigator does not have the same control over the experimental procedure that she would have in a micro-PK experiment instigated and designed by herself.  In fact, in macro-PK research, experimental procedures and conditions often must be negotiated with the psychic if he is to perform at all. Consequently, proper procedures are much less well-defined in macro-PK research than they are in micro-PK research.  As most special macro-PK subjects are suspected of, and accused of, fraud by skeptical scientists and writers, the suspicion arises that these psychics will not perform unless they have succeeded in negotiating conditions and procedures that will allow them to produce the alleged macro-PK phenomena fraudulently. Thus, there is considerable debate, both within and outside the parapsychological community, over the adequacy of the methods and safeguards taken in macro-PK research.  In fact, several macro-PK subjects have indeed been detected in fraud, as will be discussed in greater detail in the section on subject fraud below.

Separation of Psi Modalities

In the beginnings of experimental parapsychology, it was thought possible to separate psi abilities into several component subtypes: telepathy (the ability to read the mind of another person or being, usually assumed to involve direct contact between minds at the mental, rather than physical, level), clairvoyance (the paranormal ability to acquire information directly from objects, such as when a subject is able to identify a card which has been hidden in a container and whose identity is known to no one at the time), precognition (the ability to foretell events that are yet to happen), retrocognition (the direct paranormal knowledge of past events), and psychokinesis (the ability of mind to influence matter directly). To this list could be added retroactive psychokinesis, the rather outlandish ability to influence events that have already occurred in the past.  This seemingly implausible psi power was first proposed to exist by Helmut Schmidt (1975a, 1975b, 1984), who has since gone on to amass a considerable amount of experimental data in its support (see Schmidt , 1976, 1981, 1985, 1986, 1993; Terry & Schmidt, 1978; Gruber, 1980; Schmidt, Morris & Rudolph, 1986; and Schmidt & Schlitz, 1988).  In a typical retroactive-PK experiment, a subject may be asked to use his mental abilities to increase the rate at which one of two lights comes on.  Unknown to the subject, the behavior of the lights is governed by the output of a random event generator (REG) of the “Schmidt machine” type that was generated two weeks previously.  Thus, the subject’s covert task is to extend his PK influence backward in time to influence the behavior of the REG two weeks in the past.  Schmidt has actually provided a fairly plausible account of why such retroactive PK effects might be expected to occur, based on his reading of quantum mechanics.  Schmidt, along with many other theorists, believes that the outcome of a quantum process does not take on a definite value until it is observed by a conscious being (even if a considerable period of time elapses before the observation takes place). 

Separation of Types

Precognition.  Early on in parapsychology, it became apparent that it was difficult to establish the existence of any of these pure forms of psi in a definitive manner.  For instance, in Schmidt’s four-button precognition experiment, instead of using precognition to guess the identity of the correct lamp, the subject may rather be pushing a button and then using her psychokinesis to cause the correct lamp to light up. 

Recently, Steinkamp (2003, submitted) has attempted to test PK counterexplanations of the evidence for precognition by conducting an experiment in which an ESP target was determined through a complex calculation involving future closing prices of stocks.  Her experiment failed to produce statistically signification evidence of precognition, which she took as evidence that precognition does not exist; however, the results of her nonprecognitive ESP control trials also failed to be statistically significant.  Thus, her experiment failed to produce any evidence of psi scoring at all.  As critics of parapsychology are fond of pointing out, it is impossible to “prove” a negative hypothesis such as the nonexistence of precognition.  To use William James’ favorite example, no number of black crows can falsify the hypothesis that white crows exist, and one white crow would establish the truth of that hypothesis.  (Even an exhaustive search of the terrestrial avian population may not suffice for a determined believer who may respond by postulating the existence of extragalactic white crows.)  Thus, Steinkamp’s negative evidence does not disprove the existence of precognition (or of ESP in general for that matter).  

Steinkamp’s experiment is based on the argument that stock market data would be impervious to psychokinetic manipulation due to the large number of persons with a vested interest in the behavior of stock prices, whose own PK efforts would be expected to overwhelm those of Steinkamp’s subjects.  

While this argument might have much validity regarding the rise and fall of the prices of individual stocks, it is not clear that the general public has a vested interest in the outcome of a complex mathematical manipulation of the closing prices of several stocks to select a target from a target pool.  Also, parapsychologists have generally found the strength of psi effects to be unrelated to the complexity of the target systems (see Stanford, 1978; Schmidt, 1984; and Foster, 1940).  What would be needed to settle this issue is an experiment to see if subjects can subtly manipulate the collective behavior of stocks through PK to produce a desired outcome in regard to target selection.

In designing her experiment, Steinkamp followed the thought of her mentor Robert Morris, who held the Koestler Chair in parapsychology at Edinburgh University up until the time of his recent death and was responsible in large part for the growth in European parapsychology over the past two decades.   Morris (1982) argued that experiments that have used complex procedures to determine an entry point into a random number table to generate the targets for a precognition experiment, such as the complex procedure using 10-sided dice used by Mangan (1955) or Nash’s use of stock market data (Nash, 1960) provide a strong suggestion that “true precognition” exists.  However, as noted above, in view of the task-complexity independence and goal-orientation of ostensible PK phenomena, it may be premature to assert that such systems are not susceptible to PK influence on the basis of their complexity.   

Perhaps, at this stage of the game, the best evidence for pure precognition comes from cases of spontaneous psi. Even in this regard, Tanagras (1967) has argued that all cases suggestive of precognition can be explained away on the basis of psychokinetic induction of the precognized event.  Thus, a woman harboring an unconscious death wish against her husband may dream of her husband’s dying in a car crash and then use her psychokinetic powers to cause the accident itself.  Similarly, Eisenbud (1982a) proposed that all instances of ostensible precognition may be explained in terms of forward causal chains (in which causes precede their effects in time).  Such explanations might involve unconscious inferences, psychokinetic influences and “real time” telepathic interactions between the parties involves.  Mundle (1964) has also expressed a preference for explanations of precognitive experiences that employ only forward causal chains, primarily on the basis of what he perceives as insurmountable difficulties with multidimensional models of time (about which more will be said in the next chapter).

Many parapsychologists reject PK-based counterexplanations of cases of ostensible precognition on the basis that some cases on record involve mine collapses, plane crashes, tornados, and other events that make Carrie’s high school prom look like an idyllic class picnic in comparison.  They argue that, aside from these precognition cases there is little evidence that events of such a magnitude can be produced through psychokinesis.  However, in making his case against precognition, Eisenbud asserted that no limitations on PK influence should be assumed.  With respect to the experimental evidence for precognition, Targ and Harary (1984) cite the fact that scoring rates are typically not as high in successful PK experiments as they are in successful precognition experiments as evidence against the hypothesis that the experimental evidence for precognition can be explained on the basis of psychokinesis.

Telepathy.  There is a similar difficulty in separating telepathy (direct mind to mind interaction) from clairvoyance (direct knowledge of a target object).  For instance, in a telepathy experiment in which a percipient attempts to guess what card a sender is looking at, it is quite possible that the percipient may use her clairvoyant powers to read the card directly rather than reading the mind of the sender.  Alternatively, if the sender is merely thinking of a card, the identity of which he will announce later, the percipient might use precognitive clairvoyance to access whatever physical record of the target is later made.  Also, even if a seemingly pure test of telepathy could be devised, any alleged telepathy on the part of the percipient could be interpreted as clairvoyant perception of the brain state of the agent.  Such considerations led J. B. Rhine (1974) to call the existence of telepathy an “untestable hypothesis” and to recommend that the problem of proving the existence of pure telepathy be “shelved.”  Also, the experimental evidence for ESP is confronted by counterexplanations in terms of PK in the same way that the experimental evidence for precognition is.

PK. It is also possible that much of the evidence for PK, especially that arising from micro-PK experiments with REGs as targets, might be explained in terms of precognition.  Specifically, consider Schmidt’s experiment with his cat and its heater lamp, as described above (Schmidt, 1970).  Rather than assuming that the excess of “on” signals is due to the cat’s PK abilities, it might be argued that Schmidt used his precognitive ability to initiate the experiment (e.g., by pushing a button) at the precise time that a series containing an excess of “on” signals was about to be generated.  As evidence that the experimental evidence for PK can be explained on the basis of such psi-mediated “decision augmentation,” May, Utts and Spottiswoode (1995) cite the fact that the statistical significance levels in reported PK experiments with REGs as targets do not increase with the number of trials in the experiment.  (Normally, one would expect that, if the subject’s PK scoring rate is constant, this would result in an increased level of statistical significance.  For instance, while there is a 3% chance that 53% of more of 1000 flips of a fair coin will come up “heads,” there is only one chance in a billion that 53% or more of 10,000 coin flips will come up “heads.”  This is known as “the law of large numbers” in statistics: the greater the number of trials, the less likely it is that one could achieve a given above-chance scoring rate by “sheer luck.”)  Thus, May et al. construe the fact that the statistical significance of PK experiments does not increase with the number of trials as evidence against a PK influence on the part of the subjects.  

The lack of dependence of the statistical significance level on the number of trials is certainly evidence against the hypothesis that subjects’ PK scoring rates per trial will be the same no matter what the number of trials.  However, it is not inconceivable that subjects may tire with increasing numbers of trials or may not be able to devote full attention to each trial if the number of trials per unit of time is increased  (as is often the case with large sample PK experiments).

It should be noted that Dobyns and Nelson (1998) have examined the database of PK trials compiled at the Princeton Engineering Anomalies Research laboratories and have found the results to be compatible with the constant PK scoring rate hypothesis in that statistical significance does increase with increasing numbers of trials.  Similarly, Ibsen (1998) found that PK scoring rates did not differ significantly between 200 binary trials and 2 million binary trials, contradicting May et. al’s “decision augmentation theory.”  

However, Pallikari (2004), in a largely graphical analysis of the results of PK tests with random event generators, found that the size of the obtaining hitting rate declined with the square root of the number of trials, as would be predicted by May et al.’s “decision augmentation theory.”  Pallikari further found that that the reported odds against the effects being due to chance were generally less than 1 in 100 million, whereas if the effects were due to a constant PK-hitting rate, the odds would be expected to increase without bounds as the number of trials increases.  Pallikari proposes this as a type of “ceiling” on the level of significance that can be obtained in a single PK-REG experiment.  Pallikari also contends that the existing evidence indicates that human subjects can create a “broadening” in the hit rates produced in single experiments but cannot impose a specific hit rate over multiple trials.  Pallikari notes that human PK influences act to increase the numbers of runs of hits or misses within an experimental series, which will tend to balance out to chance expectation over a long series of runs.

The debate over May et. al’s “decision augmentation theory” is by no means resolved and is an active area of investigation at the present time.

Means of Resolution.  Because of the difficulty of obtaining an experimental separation of the various types of psi phenomena, the parapsychologists Robert Thouless and B. P. Wiesner suggested adopting the neutral term “psi” to designate parapsychological phenomena of unspecified type (Wiesner & Thouless, 1942; Thouless & Wiesner, 1948).  They further suggested that psi might be broken into psi-gamma, the receptive type of psi seen in clairvoyance, telepathy and precognition experiments, and psi-kappa, the active type of psi generally seen in PK experiments (although as we have just seen, it may be difficult to distinguish between these two types of ability in practice). The British psychologist John Beloff (1979b) has argued for the retention of the traditional categories of psi in general and of telepathy in particular.  Beloff feels that interpretations of phenomena suggestive of telepathy in terms of clairvoyance of brain states is questionable, as it is doubtful that a person could interpret the idiosyncratic “neural code” employed by another person’s brain.

Parapsychologists continue to use terms such as precognition, clairvoyance and psychokinesis in describing their own experimental procedures, but these typically refer to the experimental task as described to the subject rather than implying that a particular set of experimental results is definitely due to, say, precognition rather than PK.

Criticisms of Parapsychological Research

We will now turn to an examination of the controversies surrounding experimental work in parapsychology, the lessons that may be learned from them regarding proper methodology and the reasons for the continuing resistance of the scientific establishment to experimental psi research.

Irrational motives. Before plunging into a discussion of the various “rational” criticisms that have been made of experimental methodology such as charges of statistical and methodological errors in psi research and allegations of fraud by subjects or experimenters, it may be instructive to consider first the possible irrational thought processes that may account for the fact that some people seem to rush to embrace a belief in psi phenomena while other people summarily dismiss the possibility that psi phenomena may exist, often before examining the evidence for such phenomena.  The irrational bases for both belief and disbelief in psi may include emotional and religious motives, metaphysical prejudices and the various types of illogical reasoning that often underlie the formation of attitudes in general.

To begin with, at least some skeptics have indeed manifested a fairly closed-minded and prejudiced attitude against psi research.  The reader will recall from Chapter 0 the quotations from the eminent psychologist Donald Hebb and the equally eminent physicist Hermann von Helmholtz that no amount of evidence would suffice to convince them of the existence of psi phenomena. 

In part, this rejection is based on the perception that the existence of psi phenomena would be incompatible with known scientific principles. Certainly it is true that it would be hard to explain ESP and PK on the basis of currently understood physical processes. This does not, however, imply that psi phenomena are necessarily in conflict with any known laws of physics (except perhaps for certain types of psychokinetic phenomena). In fact, not only are many of the theories proposed by parapsychologists to account for psi compatible with known scientific principles, a large number of them are even based on such principles (these theories will be discussed more completely in the next chapter).  It is probably true that the ultimate explanation of psi phenomena will require the postulation of new entities or processes that are not part of current scientific theories, but this does not mean that psi phenomena need violate any established law of science, as will be made clear in the succeeding chapter.  In this light, the (a priori) resistance of orthodox scientists may be based more on a desire for closure or a tendency to see the work of science as being completed than on any real logical contradiction between psi phenomena and established theories. 

With such a desire on the part of some scientists to see the picture of the world constructed by science as finished and final, it is not surprising that there is antagonism toward psi phenomena, with their implication that current scientific pictures of the world are incomplete.  This “principle of closure” was recognized by the Gestalt psychologists as a common psychological tendency arising from the pressure to achieve a solution to a problem-solving task.  One way a person may reduce such psychological pressure is to enter a state of premature closure, in which the problem is viewed as having been solved when in fact it has not been.  This tendency toward closure is illustrated in comments by the biologist Sidney Fox, who argues that, if new laws are required to explain the emergence of life, then they lie “outside the realm of science”  (Fox, 1988, p. 45).  Fox thus equates science with established scientific theories rather than with the process of scientific discovery.  

Religious motives. There is no doubt that the same psychological needs that promote belief in various religions (including desires for control over the elements, knowledge of the future, protection from natural forces and the vagaries of chance, power over disease, and a life after death) are also responsible for the widespread belief in parapsychological phenomena.  Modern science has discredited naive and literal interpretations of many religions, and for many people parapsychology fills the void thus created.  Parapsychology not only has all the accouterments of science itself but also promises to satisfy most of the psychological needs underlying religious belief through its alleged demonstration of such paranormal phenomena as psychokinesis, precognition, psychic healing, and the survival of death.

Religious motivations and a desire to overthrow what they regarded as the depressing mechanistic cosmology proposed by nineteenth-century science formed an explicit and openly acknowledged part of the motivations of the founders of the Society for Psychical Research (S.P.R.) in late nineteenth century Britain.  Prominent among these concerns was unquestionably the fact of death with its promise of total annihilation of the human personality.  This great concern of the early psychical researchers with the problem of the survival of death was undoubtedly in part attributable to the biological instinct for survival as well as a desire to be reunited with lost loved ones.  As noted in Chapter 0, this fear of death arises in part from the identification of oneself with the Person (the physical body conjoined with the collection of memories, motives and emotions that comprise one’s personality) rather than a potentially recyclable field of pure consciousness.

It is well known, for example, that the public’s interest in mediums and seances, with their offer of a chance to communicate with deceased loved ones, tends to increase markedly during and after times of great tragedy, such as world wars.  As psi phenomena seemed to contradict the exclusively materialistic outlook of nineteenth century physics and to point to a mental realm over and above the physical world, they were readily embraced by persons seeking scientific support for the concept of a spiritual realm.  Indeed, as recently as 1982, upon the occasion of the centenary of the founding of the S.P.R., the prominent British parapsychologist John Beloff (1983) asserted in his presidential address to the Parapsychological Association that the survival of death was contingent upon the existence of psi.  This is probably a questionable assertion, as it is quite conceivable that the mind could survive death even if it did not possess the powers of ESP and PK, but it does show how closely related the issues of the existence of paranormal powers and the survival of death are in the minds of many parapsychologists.

The scientific community may in turn have feared (and may still fear) a trend toward irrationalism and a possible reemergence of religious persecution with an accompanying attempt to suppress scientific doctrines.  Certainly the memory of the Christian resistance to the heliocentric (sun-centered) model of the solar system has never been far from the consciousness of the scientific community.  In more recent times, the scientific community has been concerned with attempts to suppress the teaching of Darwin’s theory of evolution in the public schools in America and to insert various creationist theories into the biology and physics curricula.  Certainly, the credulous attitude of many elements of the public and even some self-proclaimed parapsychologists toward various purported paranormal phenomena has done little to lessen the skeptics’ fears. The skeptics, however, do a disservice to the enterprise of rational inquiry when they misleadingly classify parapsychologists who adhere to the principles of science in their investigations of purported paranormal phenomena together with wide-eyed believers in the Loch Ness monster and Bible-thumping creationists.

Psychodynamic factors. Paranoid mechanisms undoubtedly account for some portion of the belief in psychic powers, especially one’s own psychic powers.  Paranoid delusions of persecution, for instance, commonly include the belief that one’s enemies are paranormally monitoring and manipulating one’s thoughts. James Alcock (1981) is among several skeptics who contend that such “magical thinking” also underlies parapsychologists’ belief in psi.

On the other hand, ardent disbelief in psi phenomena could be construed as a form of defense against paranoid thoughts (and the causal efficacy of unconscious wishes) or as fear of the uncanny and unknown.  Charles Tart, a psychologist well known for his studies of altered states of consciousness, has attributed skepticism toward psi phenomena to a “primal repression” of threatening telepathic interactions between mother and child (Tart, 1982).  In an attempt to document such a widespread fear of psi, Tart asked subjects to imagine that they possessed extraordinarily strong psi powers that were effective within a 100-yard radius.  He found that the reactions of the subjects in this “belief experiment” were predominantly negative (Tart & Lebore, 1986).  The Australian researcher Harvey Irwin (1985) found fear of psi to correlate negatively with sympathy for psi research, lending support to Tart’s contention that such fear forms a motivational basis for skepticism.  Such fears of psi are sometimes explicitly stated by skeptics.  For instance, the prominent skeptic Robert Baker (1990) expresses his horror at the thought that psi powers might exist, as that would imply that physical disasters might result from the slightest angry thoughts, privacy would be at an end, and the world would be populated by human monsters. 

Social and attitudinal processes. Obviously, the subfield of social psychology known as “attitude theory” may have much to tell us about how attitudes toward parapsychology are formed. According to Hovland, Janis and Kelly’s (1953) reinforcement theory of attitude formation, one tends to hold beliefs that one has been rewarded for expressing and to extinguish beliefs for which one has been punished for expressing.  To express a belief in psi phenomena or to pursue psi research may result in a loss of tenure and funding and a general ostracism from the orthodox academic community. Thus, as the reward structures within the academic community tend to favor anti-psi beliefs, one would expect them to engender skepticism. Of course, the propensity of some members of the lay public to provide monetary support and sometimes even adulation to investigators expressing belief in psi powers might be a factor serving to increase belief in psi among such investigators.

According to Festinger’s “cognitive dissonance” theory, one method of avoiding the stress arising from an inconsistent belief system is to avoid exposure to high-quality communications and arguments that run counter to one’s own position on a given issue (Festinger, 1957).  This might explain the tendency of some parapsychologists to ignore or repress legitimate and constructive criticisms of their methodology.  Sometimes this can result in disaster, as illustrated by the case of Project Alpha, in which researchers at Washington University in St. Louis were deceived by stooges of critic James “the Amazing” Randi posing as metal-bending psychics, primarily because the researchers failed to employ safeguards suggested by Randi (Randi, 1983a, 1983b, 1986).  Project Alpha will be discussed in more detail in the section on subject fraud below.

On the other side, critics often fail to heed (or at least discuss) the better-conducted studies in the field of parapsychology.  Occasionally, critics write books and articles debunking the weakest claims in the field, such as Arthur Conan Doyle’s alleged pictures of fairies (Randi, 1980) and the psychic entertainer Kreskin’s stage performances (Marks & Kammann, 1980), while at the same time claiming to have debunked the entire field of parapsychology.  This may be understandable in light of the fact that the scientific community’s main concern may be directed toward a possible trend toward irrationalism (and the concern of magicians such as Randi may be directed at possible dishonest and attention-stealing uses of conjuring techniques). The primary concern of such critics may thus not be so much with “legitimate” parapsychology, but with clearly quack science and charlatanism. To the extent that this is the case, parapsychologists should applaud their efforts (but not their claim to have debunked the entire field of parapsychology).

Another technique for avoiding a sense of cognitive dissonance is to reduce the psychological importance of an issue about which there is conflict.  I recall the remarks of one prominent cognitive psychologist who told me that, although he did not know whether parapsychological phenomena existed or not, he did not see why they were of any importance (perhaps reflecting his concern as a psychological rather than a physical theorist).  A related strategy for reducing the stress of cognitive inconsistency is to “stop thinking” (Abelson & Rosenberg, 1958).  To some extent, this has been the traditional response of academic psychology to the claims of parapsychology, which are almost never discussed in any detail in the academic curricula of psychology departments. Because of this “heads in the sand” approach, departments of psychology have in many instances failed in what should be their responsibility to provide a responsible (even if skeptical) discussion of alleged parapsychological phenomena, a topic that is of great interest to students and to the public in general.

Lack of social support for one’s beliefs is another source of cognitive dissonance, according to Festinger.  Certainly, the tendency of people to conform to group opinion, the pressure put upon people to conform to majority opinions by groups, and the tendency of people to obey authority figures have been amply demonstrated in classic psychological experiments by Asch (1958), Schachter (1951), and Milgrim (1963, 1968).  Within the academic community, one would expect such pressures to favor skepticism with regard to psi phenomena. One way to decrease the cognitive dissonance arising from lack of social support is, according to Festinger, to decrease the perceived attractiveness of the disagreeing parties (which might result in a skeptic classifying all parapsychologists as fairy-worshipping lunatics or a parapsychologist classifying all skeptics as unimaginative, narrow-minded bigots). 

In closing, it should be noted that the denial of funds and professional opportunities is not confined to parapsychologists but is a problem faced by non-mainstream scientists in general.  Eliot Marshall (1990), for instance, describes the denial of telescope time to heterodox plasma theorist Halton Arp, depriving him of the opportunity to make even basic observations.  By restricting telescope time to supporters of orthodox views, Marshall notes, the process of science is thereby distorted and the potential for dialogue between opposing views closed off.  (Indeed, the possibility of observationally-supported heterodox views even arising is virtually eliminated).  As a resolution to this problem, Marshall recommends that some funds be allocated to non-mainstream scientists, without requiring the process of “peer review” by advocates of orthodox positions.  

Rational Bases

We will now consider more rational grounds for the rejection of psi phenomena that are based on legitimate concerns regarding proper methodology, the issue of the replicability of the effects and the possibility of fraud.  

Sensory cues. When one is attempting to establish the existence of an ability to identify target material that lies outside of the normally recognized channels of the physical senses, it is obviously important to exclude the possibility that the subject’s knowledge of a target is based on “sensory cues” (that is, information acquired through the usual physical senses).  The early days of experimental parapsychology were not characterized by the stringent safeguards against sensory cues that are (usually) employed today.  For instance, an “agent” might sit at one end of a table, pick up an ESP card and attempt to project its identity into the mind of a percipient seated at the other end of the table.  Under these circumstances, the percipient might learn the card’s identity by seeing the card reflected in the agent’s eyes or by picking up on cues unconsciously provided by the agent (such as tilting the head when viewing a “star,” etc.). The behaviorist B. F. Skinner pointed out that the cards in the Zener ESP deck used by Rhine in his early experiments could be read from the back under certain lighting conditions, invalidating any experiment in which the percipient could see the backs of the cards.  Parapsychologists were quick to respond to such critiques by totally isolating the subject from the targets (such as by having them in a separate building, as was done in the Pearce-Pratt series discussed previously, for instance).  Most forced-choice experiments in parapsychology today are characterized by adequate shielding of the target from the percipient.  Exceptions do of course still occur, as no field is immune from methodological errors committed by its practitioners.  For instance, Don, Warren, McDonough and Collura (1988) report an experiment in which the ESP cards used as targets were placed directly on the hand of the special subject (Olof Jonsson), allowing him access to possible sensory cues arising from the back of the cards, as well as possible glimpses of the fronts of the cards.  The random number table used to generate the targets was also in the room with the subject and could have been a source of additional cues.

Rupert Sheldrake (1998b) reports an experimental investigation of the hypothesis that people know when someone is looking at them and that this knowledge is mediated by ESP.  However, in Sheldrake’s experiment, the “starer” was sitting directly behind the “staree.”  This allows for the possibility of sensory cues, in that the starer’s breathing and body movements may be different during staring trials from those during non-staring  trials.  The subject might be able to use to such cues to differentiate between staring and non-staring trials.  

In an attempt to placate his critics, Sheldrake (2001) repeated his experiment with the subjects blindfolded and trial-by-trial feedback eliminated (i.e., the subject was not told immediately after the trial whether the trial had been a staring or non-staring trial).  However, this halfhearted attempt at sensory shielding still leaves open the possibility that the subject could be responding to differences in the starer’s breathing patterns and bodily movements between staring and non-staring trials.  

Lobach and Bierman (2004a) repeated Sheldrake’s experiment with improved sensory shielding.  Also, to eliminate artifacts due to response bias (e.g., a subject who calls “staring” on 80% of the trials would be expected to have a hit rate of 80% on staring trials, not the 50% rate that would be expected to obtain across all trials by chance), Lobach and Bierman did not analyze staring and non-staring trials separately, as did Sheldrake.  In three attempts to replicate Sheldrake’s findings, Lobach and Bierman found no evidence that subjects could distinguish between staring and non-staring trials at a rate significantly greater that what would be expected by chance.  They conclude that Sheldrake’s staring detection effect is not as easily replicated as claimed by Sheldrake. 

Sheldrake (2005), however, points to the success of experiments in which the “starer” watches the “staree” over a closed television circuit in a separate room as evidence against the hypothesis that the remote detection of staring is due to sensory cues.  In this regard, he cites meta-analysis of 15 such experiments by Schmidt, Schneider, Utts and Walach (2004) indicating that there was overall statistically significant evidence of psi under such conditions.   

Sensory cues may result from more subtle flaws in an experiment.  For instance, the noted critic Martin Gardner (1981) has pointed out that a light system that was used by the “sender” to signal the beginning of the next trial to the percipient in Charles Tart’s well-known experiments on training ESP ability (Tart, 1976) might allow the sender to provide cues as to the identity of the next target through the conscious or unconscious use of a time delay code (e.g., the sender might delay the signal longer for some targets than others).  As the percipient was provided with trial-by-trial feedback, he or she might consciously or subconsciously become aware of this tendency.  As a rule of thumb, in a parapsychological experiment no person with knowledge of a target’s identity should be allowed to communicate with the subject attempting to guess that target until after the subject has made his guess.  

Sheldrake and Smart (2003) investigated the hypothesis that people sometimes know who is calling on the telephone before even picking up the phone.  Of course, as a spontaneous phenomenon, this sort of guessing may be mediated by knowledge who is likely to call at which time of day, ongoing crises and other daily events that may involve some friends (possible callers) more than others, and the amount of time that has elapsed since the person last called.  In Sheldrake and Smart’s experiment, subjects had to guess which one of four target persons was calling on the phone during a preassigned time interval.  Sheldrake’s subjects were able to identify the caller before picking up the phone with a frequency that would occur by chance less than four times in a million.  

A similar experiment was run by Lobach and Bierman (2004b).  In their experiment, one of four target persons was randomly assigned to call the subject during a preassigned five-minute time interval.  The subjects were able to identify the caller on 29.4% of the trials compared to the 25% rate that would be expected by chance (and this difference was statistically significant at the .05 level).  Lobach and Bierman note that almost all of their above chance scoring occurred around 13:30 local sidereal time (i.e., time relative to the “fixed stars” rather than the sun).

Both the study conducted by Sheldrake and  Smart and that conducted by Lobach and Bierman are susceptible to explanation in terms of a time-delay code.  For instance some callers may call early in the five-minute trial interval and others may call late.  The subject may learn to use such differences in calling times to identify the caller.  The possibility may also exist that different phones produce different rings on the receiving phone. 

It should also be noted that Schmidt, Muller and Walach (2004) attempted to replicate Sheldrake and Smart’s phone-calling experiment, but they obtained nonsignificant results.

In the same vein, Sheldrake and Smart (2000) report an experiment in which Pam Smart’s dog Jaytee seemed to know when its owner was coming home and would go to the window or the porch to await her arrival.  However, Wiseman, Smith and Milton (2000) failed to confirm Sheldrake and Smart’s results when strict quantitative criteria were used to define the event “Jaytee goes to the porch.”  They attribute Sheldrake and Smart’s results to Jaytee’s becoming more anxious regarding Pam Smart’s absence as time went on, resulting in more frequent trips to the porch and window.   

Trial-by-Trial Feedback The mathematician Persi Diaconis (1978) pointed out the danger of giving trial-by-trial feedback to a subject guessing a target pool that is being sampled without replacement, such as might occur if the subject is guessing a deck of ESP cards and being shown each card after every guess.  Such feedback would enable the subject to improve his chances by avoiding guesses corresponding to already sampled targets (e.g., if the subject guessing an ESP deck has already seen all five circle cards, he can improve his chances by not guessing “circle” again).  This is of course correct, but Diaconis’ implication that this was a typical testing procedure in parapsychology at that time is misleading.  In fact a search conducted by Charles Tart two years prior to the publication of Diaconis’ article revealed only four studies using such a procedure, three of them appearing in an unpublished master’s thesis.  Tart had labeled all four studies as methodologically defective in his review of the literature pertaining to studies employing trial-by-trial feedback (Tart, 1976).   

While it is rare for forced-choice experiments to employ trial-by-trial feedback with such a “closed deck” procedure, this does occur more often in free-response experiments, in which subjects give their subjective impression of a target rather than guessing it directly. In one type of procedure, these subjective impressions are ranked or matched against all the targets used in the experiment.  For instance, Puthoff, Targ and Tart (1980) conducted an experiment in which a subject attempted to use her ESP to describe ten different target objects.  Because the subject was shown the target object after each trial, she could, on subsequent trials, avoid giving descriptions corresponding to previously seen targets, thus artifactually inflating the probability that her descriptions would be correctly matched to the targets by the judges.  Diaconis’ criticism is clearly applicable to this sort of free-response experiment.  In a similar vein, Marks and Kammann (1978, 1980) have argued that in Targ and Puthoff’s main remote viewing research (e.g., as reported in Targ & Puthoff, 1977) the subjects’ remarks contained clues as to trial order (by referring to “two previous targets,” for example) and target identity (by explicitly referring to previously seen targets, which the judges would then know not to match with the present transcript).  Tart, Puthoff and Targ (1980) attempted to respond to Marks and Kammann’s critique by conducting an analysis showing that the results were still statistically significant even after these cues had been edited out of the transcripts.  One can of course quibble about the efficacy of the editing process, and Marks and Scott (1986) have argued that statements left in the transcripts after the editing that referred to the subject’s location could constitute residual order cues that might be used by judges.  For instance, in one trial Targ asked the subject if he noticed “any difference being in a shielded room rather than in the park.”  This was the first trial done in a shielded room.  In any event, the basic problem (namely, the avoidance by the subject of responses descriptive of previously seen targets) that arises from use of trial-by-trial feedback under conditions of sampling without replacement remains, no matter how effective one assumes the editing process was.

Cuing of Judges.  A related problem in free-response experiments involves the nonverbal sensory cuing of judges. For instance, in remote viewing experiments conducted by Bisaha and Dunne (1979), judges were provided with pictures of the target location taken on the day of the remote-viewing trial.  Thus, cues as to weather conditions, seasonal variations (e.g., foliage conditions), time of day, and so forth, could have been present in both the subject’s transcripts and the pictures, and the judges could then use these cues, consciously or unconsciously, to match the transcripts to the targets.  Bisaha and Dunne deny that such cues exist, but in the only two picture sets they reproduce from their first experiment, the leaves are still on the trees in one, whereas the trees are bare in the other.  Also, Marks (1986) has pointed out that, in Bisaha and Dunne’s experiments, the decision as to whether the subject’s drawings of his or her impressions of the target site would be presented to the judges was made on an ex post facto basis (that is, after examination of the drawings), which may have biased the information presented to the judges in favor of correct transcript-target matchings.   Marks goes on to note that the choice of which photographs of the target site to present to the judges may have been a further biasing factor.

As another example of how sensory cues may be inadvertently provided to judges in free-response experiments, one can cite the transoceanic remote-viewing experiment reported by Schlitz and Gruber (1980). In the first judging of the experiment, the agent’s impressions of the target site were included among the material provided to the judges.  This may have resulted in cues as to target order being given to the judges (e.g., the agent and the percipient might both refer to a news event occurring on a given day).  Schlitz and Gruber themselves pointed out this problem and reported a rejudging of the experiment with the cues deleted; the results were still significant (Schlitz & Gruber, 1981).  The skeptic Ray Hyman (1986) later detected a further possible source of sensory cues to judges arising from the fact that Gruber, who served as agent and hence knew the identity of the target for each trial, was responsible for translating the remarks of Schlitz, the percipient, into Italian for presentation to the judges. His translation might have been biased by his knowledge of the target site.

A very similar problem exists in two dream telepathy experiments reported by Child, Kanthamani and Sweeney (1977).  In each experiment, an agent attempted to send a different target picture into the dreams of a percipient on each of eight different nights.  The eight sets of dreams and impressions were then ranked by the agent against the eight targets.  However, as the agent knew which target was used on which night and as the percipient’s dreams might be expected to incorporate certain “day residues” reflecting the events of the prior day, the agent could have used this knowledge to match the dreams against the targets.

Most of the feedback-related problems discussed above arise from the fact that the experiments in question used a procedure involving sampling without replacement from a finite target pool, often combined with a procedure involving judging the entire set of transcripts for a series against the actual targets used in that series.  In most free-response experiments, such as the well-known research line of ganzfeld experiments, the responses are judged against a different target pool for each trial and do not suffer from the problem of sensory cuing of judges to the extent that the above-discussed studies do.  That is not to say that these experiments have been immune from such problems.  For instance, in the early ganzfeld experiments, the subject often judged his own transcripts against the same physical target pool used by the agent.  Thus, it is possible that the subject could obtain cues as to which target was actually sent by the agent by examining the target pictures for fingerprints, crumpling effects and so on. In an initial attempt to test this “greasy fingers” hypothesis, John Palmer (1983, 1984) found no evidence that subjects in fact used such cues to identify the picture held by the agent, although the results of this study were to some extent contradicted by a later study by Palmer and Kramer (1986) indicating that subjects could indeed use such cues to identify the target picture when they were specifically instructed to do so.  This problem has been eliminated in the recent ganzfeld experiments through either the use of duplicate sets of pictures, one to be used by the agent and the other by the judge, or the use of electronically stored and presented targets.

It is obvious that the problem of sensory-cuing can be a subtle one.  While the problem of eliminating sensory cues to subjects has long ago been resolved, procedures for the elimination of sensory cues to judges are still evolving.  How prevalent is the problem of sensory cuing in parapsychological research?  In order to find out, Akers (1984) conducted an analysis of a sample of 54 parapsychological experiments.  Among his criteria for inclusion were that each experiment should have produced significant evidence of psi and that the experiment be from a relatively repeatable line of research.  Consequently, Akers’ sample included a large number of ganzfeld experiments, as this is one of the lines of parapsychological research that have come the closest to producing a repeatable parapsychological experiment.  Of the 54 experiments, Akers cites 22 studies as possibly providing sensory cues regarding the target’s identity to subjects or judges.  One would suspect, however, that, had Akers’ sample included a greater proportion of (less repeatable) forced-choice studies, the proportion of studies with methodological flaws involving sensory cues would be reduced. 

Now we turn from the problem of sensory cues in ESP experiments to the related problems of motor artifacts in PK experiments.

Motor artifacts. In certain types of psychokinesis experiments, it is very important to ensure that the subject cannot use his or her motor skills to influence the target apparatus.  For instance, in a “placement PK” experiment in which a subject is attempting to use psychokinesis to influence a series of balls rolling down a chute to go into the left or right side of a collection bin, it is important to ensure that the subject cannot influence the balls by breathing on them, rocking the table, altering the air currents by changing his or her body position, and so forth.  Also, it is important to ensure that the balls be placed in the apparatus in the same way at the beginning of each trial, otherwise the experimenter may subconsciously learn how to place the balls in such a way that the desired result occurs.

As an example of such artifacts, consider an experiment reported by Egely (1986) in which a subject attempted to influence the motion of objects floating in liquid in a Petri dish.  The subject was allowed to put his hand into the shielded box and next to the Petri dish.  Thus, it is quite possible that the obtained motions of the target object might have been due to air currents set in motion through the moving of the subject’s hand.  As another example, Taylor (1980) has contended that the movement of small objects by the Russian psychic Alla Vinogradova was due to an electrostatic effect.  Specifically, he contends that a repulsive force may have been induced by electrical charges on her hands as well as on the object to be moved.  Indeed, motion pictures taken of this type of “psychokinetic” motion (which was much in “vogue” in the 1970s) do suggest this possibility, as the objects are typically a short distance from the psychic’s fingertip and moving away from it, much like a peanut one centimeter in front of the nose of a contestant in a peanut race.  Taylor also cites the fact that Vinogradova typically rubbed her hands together prior to her performances as further evidence that an electrostatic effect was responsible for the motion of the objects.

Experiments that involve an attempted psychokinetic influence of living targets should also include precautions against normal sensory-motor influence. For instance, in an experiment conducted by Barry (1968a, 1968b), subjects sat for fifteen minutes at a distance of one and a half meters from a set of ten Petri dishes, attempting to inhibit the growth of the fungus in five experimental dishes while “ignoring” the control dishes.  Under these conditions, it might be possible for a subject to influence the growth by, for instance, breathing on the dishes.  In the early 1950s, Richmond (1952) reported an experiment in which he was successful in influencing paramecia to swim to a specified target quadrant as he viewed them through a microscope.  As Richmond was obviously close to the microscope, he could have influenced the paramecia through his breath or by jiggling the slide.  Another problem in this experiment is that, while the target quadrant was randomly selected, Richmond did not use a random process to select the paramecium to be influenced; thus he may have selected paramecia already predisposed to move to the desired quadrant, as has been pointed out by Johnson (1982).

Pleass and Dey (1987) report an experiment in which subjects attempted to use their PK abilities to influence the motion of specimens of the marine alga Dunaliella.  A problem with this experiment is that the subjects were allowed to select which time periods would be the PK influence periods rather than having these periods specified in advance.  Thus, it is possible that the subjects may have been able to choose favorable periods based on sensory cues derived from observations of the algae or of environmental factors that were associated with the motion of the algae.

Fortunately, most PK experiments reported in the modern literature are relatively free from such artifacts.  Indeed, the bulk of the literature uses quantum-mechanically based Schmidt REGs as target objects, and radioactive decay is hardly subject to sensory-motor influence!

Violations of blindness. It is important in parapsychology, as in other disciplines, that measurement of certain variables be done by a person who is blind as to the values of other variables.  For instance, if an experimenter who is rating a person’s extraversion based on clinical observations during an interview already knows that person’s score on an ESP test, the experimenter may consciously or unconsciously tend to give higher extraversion ratings to persons with high ESP scores, thus artifactually producing another confirmation of the generally-obtained positive relation between ESP and extraversion.

It is also important that anyone interacting with a subject prior to his description of an ESP target be blind as to the identity of that target. For instance, Palmer and Lieberman (1976) report an “out-of-body experience” study in which an experimenter who knew the identity of the target was in the room with the subject.  This experimenter might have been able to exert some sort of subtle influence to predispose the subject to give a description corresponding to the target, without even being aware of doing so.

Persons physically interacting with PK target materials should also be kept blind as to the target.  For instance, in an experiment reported by Nash (1982), the experimenter placing fungus samples in an incubator was not blind as to which funguses were to be psychokinetically inhibited and accelerated and which were controls.  Thus the experimenter might have been able to influence the outcomes in the desired direction by selective placement of the funguses in the incubator.  Obviously, in such an experiment it is important that the person measuring the fungus growth also be blind as to the experimental condition.

An artifactual correlation between ESP scores and a personality trait may result if the subject has knowledge of his ESP score prior to taking the personality test, as the subject’s responses to the latter test may be biased by his knowledge of his ESP scores.  That this possibility is a legitimate concern is evidenced by results reported by Palmer and Lieberman (1975). They found a positive relationship between imagery score and ESP score for subjects who took the Betts Imagery Scale after getting feedback about their ESP scores, but not for subjects who took the imagery test prior to the ESP test.  On the basis of these results, they conclude that a previously reported positive relationship between imagery and ESP reported by Palmer and Vassar (1974) was probably due to the same artifact.

A “meta-analysis” of experiments exploring the relationship between ESP ability and extraversion by Honorton, Ferrari and Bem (1990) strongly suggests that much of the evidence for a positive relationship between these two variables might be due to a similar artifact.  In particular, these authors found no evidence for a positive relationship between ESP and extraversion in forced-choice studies in which the extraversion measurement preceded the ESP test.  The evidence for a positive relationship in forced-choice experiments thus appears to be an artifact of the subjects’ knowledge of their ESP scores when responding to the extraversion test.  In 11 of 14 free-response studies, the extraversion test preceded the ESP test, and a positive relationship between the two variables was still found in these studies, which is apparently not due to the artifact in question. In an attempt to test whether this artifact is indeed a problem, Krishna and Rao (1991) gave subjects false feedback as to their ESP scores in order to see if such feedback would indeed bias their responses on a personality test. They did not find a significant difference in extraversion scores between subjects given positive and negative false feedback, in opposition to the bias hypothesis. It should, however, be noted that there was no significant relation between extraversion and (real) ESP scores in this study.

As a general principle, recording or measurement of experimental conditions and targets and of the related psi effects should be carried out under conditions of mutual blindness in both PK and ESP experiments.

Due to the defensive stance parapsychologists must take in light of criticism by a community of hostile skeptics, parapsychologists tend if anything to be more careful about blindness violations than most scientists. In his analysis of 54 parapsychological experiments, Akers (1984) cited nine for having flaws involving the nonblind measurement of personality variables.  As Akers’ sample included a large number of studies relating personality variables to ESP, this is probably an overestimate of the rate at which blindness violations are committed in parapsychology.  In a review of the more recent scientific literature, Sheldrake (1998a) found that blinding procedures were used more often by parapsychologists than by researchers in other fields.

Nonrandom target selection. In order to eliminate the hypothesis of chance coincidence, it is important that the targets in parapsychological experiments be selected randomly.  It will not do, for instance to have a person select a target by thinking of a number between 1 and 10, as certain numbers are more likely to pop into his mind (and the guesser’s) than are others, raising the probability to a correct guess above the chance level of 0.1.  For instance, in an early experiment by Tyrrell (1936), the subject had to guess which of five targets lamps would be lit on each trial.  In the initial stages of the research, Tyrrell himself selected the targets, attempting to be “random” but not employing any formal randomization procedure.  Thus, the subject could quickly learn Tyrrell’s favorite targets and guess these more frequently than the others.  She could also increase her score by not calling lamps that had just been lit or by calling the same lamp again if it had not been lit on the previous trial (as people attempting to produce a random sequence of targets tend to avoid repetitions, thus producing sequential dependencies in the target series).  Therefore, the subject could expect to do much better than the twenty percent hit rate expected by chance.  This sequential dependency problem was pointed out to Tyrrell by G. W. Fisk, and the experiment was continued using random numbers to select the targets. Under these conditions, the subject was still able to achieve a highly significant score.

Blackmore (1984c) criticized a study by Spinelli (1978) on the basis that the children who served as agents in Spinelli’s experiment were simply allowed to choose which picture they wished to “send” to the percipient via ESP.  This is Tyrrell’s initial flaw in a more modern guise.

Randomization of target selection has also been a problem in some free-response experiments involving the drawing of pictures, including the classic initial experiments reported by Upton Sinclair (1930/1962) and Rene Warcollier (1948/1964).  In more recent times, this problem has been exemplified in the picture-drawing experiments with the psychic Uri Geller at Stanford Research Institute conducted by Targ and Puthoff (1977).  In these experiments, the target was generated by opening a dictionary “at random” and drawing the first “drawable” word on the page.  (Which words are to be considered “drawable” is an arbitrary decision that may itself disqualify the target selection process as a truly random procedure.) The investigators allowed considerable latitude in the interpretations of the word in the target drawing.  For instance, the one target selection that Targ and Puthoff describe in detail involved the word “farmer.”  In the target drawing, the farmer is equipped not only with a pitchfork, but also with horns and an elaborate tail; in addition, the label “Devil” appears above the figure.  If Geller and the target preparer had just been viewing The Exorcist, for instance, that common experience could account for both the target drawing and Geller’s religiously oriented response. This amount of latitude in interpretation destroys any claim to random selection of the target.

Nonrandom target selection has also plagued some recent remote viewing research. For instance, in the “volitional mode” technique employed in the “remote perception” studies by Jahn and Dunne (1987) and conducted at the Princeton Engineering Anomalies Research (PEAR) center, the target to be visited was merely selected by the agent rather than chosen randomly from a prepared target pool (no such pool even existed on these trials).  Also, in Jahn and Dunne’s experiments, the agent was frequently allowed to wander from the assigned target area, to take photographs and to write descriptions of the target area.  As these materials were provided to the judges, they essentially constitute the target. The agent was therefore free to construct a target that might match the verbal transcript likely to be provided by the percipient on that particular day. In 211 of Jahn and Dunne’s 336 formal “remote perception” trials the agent was free to choose or construct the target in a nonrandom manner.  

In the most recent work on “remote perception” conducted by the PEAR team, as described in Dunne and Jahn (2003), the procedure is to have the agent and percipient check off a list of “descriptors” regarding the target location (e.g., whether the scene is “confined or expansive,” whether it is “noisy or quiet,” whether it involves the presence of water, is indoors or outdoors, etc.).  The degree of match between the descriptors checked (or rated) by the percipient and agent are then compared to the statistical distribution of matches between the percipient’s descriptor list and those provided for other locations on other trials.  However, the same problems exist as for the pictures taken by the agent in Dunne’s early research.  The location is not the target, rather the target is the agent’s description of the location.   Common thought processes and common experiences could thus lead the agent and the percipient to provide similar descriptions.  For instance, if they are in glum mood, they may both rate the location as “confined and quiet” rather than as “expansive and noisy.” 

The procedure of comparing descriptor lists for the target to the descriptor lists of the targets used on other trials also runs into the problem that the percipient may consciously or subconsciously avoid given descriptions that correspond to previously seen target locations. 

There is a very clean procedure that would avoid all of these problems.  Create a pool of targets for each trial prior to the trial.  Have the target descriptions prepared before the trials.  Then choose a target location randomly from the pool, and compare the correspondence of percipient’s description with the chosen target location against that with the alternative locations that were not selected.  This procedure was pointed out to the PEAR team by Hansen, Utts and Markwick (1992) in their extensive critique of the PEAR remote perception research, and more recently as applied to the descriptor lists by Stokes (2004).  

In his analysis of a sample of 54 ESP experiments, Akers (1984) concluded that target randomization was informally done (e.g., by hand-shuffling of cards) or inadequately described in about half of the studies.  Some of these randomization flaws may be debatable (e.g., the fact that an “untrained agent” prepared targets from a random number table).  He also found that randomness tests were not conducted on the apparatus used in 10 out of a sample of 27 psychokinesis experiments.  He further notes that control runs are done infrequently in PK experiments and calls for an increased use of control runs as well as for more frequent randomness checks on the equipment to be performed during the experiment and within the actual experimental environment.

Statistical Controversies

The use of improper statistical tests. In parapsychology as in any other science, researchers do occasionally apply inappropriate statistical tests to their data or commit other statistical errors.  As universal perfection is not likely to be achieved in any field of study, the rate at which such errors occur is not likely to be reduced to zero.  In recent years, however, parapsychologists have been fairly meticulous about ensuring that the statistical tests they perform are appropriate to their data.  They have been held to higher standards than the practitioners of other disciplines due to unrelenting and vigorous attacks by critics.  Thus, the statistical practices of parapsychologists tend, if anything, to be a little more rigorous than those of many other scientific disciplines. Some researchers will always be more competent than others, and some errors are bound to occur from time to time.

Attacks on probability theory itself. There have been some critics who have gone so far as to suggest that basic tenets of probability theory should be given up in order to avoid swallowing the bitter pill of the existence of psi.  Among them are George Spencer Brown (1953, 1955, 1957), J. Barnard Gilmore (1989), and James Alcock (1981).  This would be more than throwing out the baby with the bathwater.  The whole family tree would be getting the toss, because virtually all branches of science reply on statistics and probability theory to reach and justify their conclusions.

In this context, it should be noted that there are other writers, such as Arthur Koestler and Alister Hardy, who have also argued for the existence of basic flaws in probability theory (e.g., Hardy, Harvie & Koestler, 1975; Koestler, 1978).  They differ from the critics mentioned above primarily in terms of motivation. They see such flaws as supporting the theory of synchronicity or meaningful coincidences promulgated by Carl Jung. (Jung’s theory of synchronicity will be taken up again in the next chapter.)

Specifically, Koestler argued that the “law of large numbers” constitutes a paradox in probability theory.  This law asserts, for instance, that if an unbiased coin is tossed a large number of times, the obtained proportion of heads will be very nearly equal to the value of 1/2 that would be expected by chance.  Koestler contended that this requires an “acausal connection” or conspiracy among parts of the series such that an initial run of, say, heads will be balanced by a later run of tails. However, the law of large numbers is mathematically derived from the precise assumption that no such conspiracy exists, that is to say, that the outcome of one trial has no effect on the outcome of any other.  Thus there is no need for, and indeed no room for, Koestler’s proposed mysterious acausal connections.  After all, the fact that the laws of probability theory are obeyed in the law of large numbers hardly constitutes evidence against those laws!

There have been several critics who have objected to parapsychologists’ comparison of their data to theoretical distributions derived from the theory of probability rather than to empirical control groups (e.g., Calkins, 1980; Alcock, 1981; Girden, 1978; Moss & Butler, 1978; Gilmore, 1989; Hyman, 1996).  In this context, the skeptic James Alcock has contended that the comparison of experimental with control groups “makes artifact only a minor problem” in “normal” science (Alcock, 1984, p. 317). However, in a crude (and methodologically unacceptable) PK experiment in which coins are tossed by hand, motor skills could be used to increase the number of heads in the “heads” condition and the number of tails in the “tails” condition.  Thus, the use of a control group would hardly eliminate all artifacts in this case, as it would not in the case of a psychology experiment in which violations of blindness could lead a researcher to treat subjects in his experimental and control groups differently, perhaps in the process consciously or unconsciously using subtle means to make them behave in such a manner as to confirm his hypothesis.  Use of a control group does not automatically eliminate all sources of experimental error, as Alcock seems to assume.

Some critics have even chastised parapsychologists for their use of control groups. The well-known critic C. E. M. Hansel (1980) has criticized Helmut Schmidt for using a high-aim condition (in which subjects try to guess which of four lamps will be lit) and a low-aim condition (in which subjects try to guess a lamp that will not light) in the second experiment in his investigation into the precognition of a quantum process (Schmidt, 1969), which was discussed earlier in this chapter.  In Schmidt’s experiment, the subject indicated his or her response by pushing a button on the machine, and the guess and target for each trial as well as the type of condition (high- or low-aim) were recorded on tape. Schmidt’s low-aim condition thus served as an excellent control for his high-aim condition (and would guard against some types of possible machine artifacts). Hansel makes the point that the overall results were not significantly different from chance. However, when the results are scored in the intended direction (that is, high- or low-aim), they are highly significant.  Hansel also recommends that different machines be used for the high- and low-aim conditions. However, as the machines could each be mechanically biased in the desired directions, this would negate the advantage of using the same machine as a control for itself.

Thus, parapsychologists are caught in a double bind, as critics have castigated them both for their employment of a control condition and for their failure to employ one. They use theoretical distributions to attack parapsychological work (as Hansel did in attacking Schmidt) but disapprove of parapsychologists’ use of the same distribution (Alcock, Hyman).  Hansel also uses a theoretical distribution to attack results showing differences in psi scoring rates between groups of subjects (such as extraverts and introverts, for example) when he notes that, although the groups differ from one another (one scoring above chance and one below), the overall score does not differ significantly from chance.

It should also be noted that the traditional statistical tests of differences between experimental and control data themselves rely on theoretical distributions (such as the t distribution). In any event, Akers (1984) points out that, in his analysis of a sample of 54 ESP studies, the statistical tests used were directed at a comparison between empirically obtained means in about two-thirds of the cases, so the use of purely theoretical distributions is by no means as rampant as these critics have charged.

Multiple analyses. It is possible for a parapsychologist to conduct so many statistical tests on his data that some of them would be expected to be significant purely by chance.  If you try hard enough to find patterns in random data, you will eventually be successful. These patterns will be meaningless, however, as they represent nothing but the fluctuations that would be expected to occur by chance. There are mathematical corrections that may be used to take the number of analyses performed on the data into account, and these are increasingly being used by parapsychologists.

A related problem is that of post hoc analysis. Suppose a researcher glances at her data and happens to notice that female subjects tended to get higher ESP scores in her experiment than did male subjects.  If she runs a test to see if this difference is statistically significant, we once again run into the problem of multiple analyses, as we have no way of how many potential patterns of this type might have “caught her eye” had they been present in the data.  In this case, it is impossible to correct for the number of analyses performed, as it is unclear how many different patterns could have been noticed by the experimenter.  The proper thing to do in this case would be for the researcher to label her finding as “post hoc” and as only providing a suggestion that an effect might be present. The demonstration of the effect’s reality would have to involve further experimental testing to see if the effect occurred again. It is crucial in parapsychology as in all areas of scientific investigation that the hypotheses that are to be tested in an experiment be stated before collecting and examining the data.

In his review of 54 ESP experiments, Akers (1984) cites only two studies for flaws involving multiple analyses. He disputes skeptic Ray Hyman’s contention that 39 of 42 ganzfeld studies suffer from flaws involving multiple analyses (Hyman, 1983), based on the fact that which analysis should be regarded as the primary analysis in these studies could be inferred from the author’s previous practices.

Data selection. If only a portion of the data of a parapsychological experiment is singled out for analysis on an ex post facto basis (e.g., because the hitting rate was particularly high for this portion of the experiment), a spurious psi effect may be generated, as improbable subsequences will exist in any sufficiently long series of random events.  Stenger (1990), for instance, claims that data selection took place in the picture-drawing experiments conducted with Uri Geller at Stanford Research Institute, insofar as many unsuccessful trials were never reported or included in the overall analysis.  Data selection within a single study has become a less frequent problem in parapsychology over the years (except for the data selection inherent in many post hoc analyses, as discussed above).  Akers (1984), for instance, classified only 4 of the 54 ESP studies in his sample as having results that could be attributed to data selection.

One special type of data selection involves what is known as “optional stopping.” This occurs when a researcher is monitoring the data of the experiment and waits until an opportune time to stop the study (“quitting while he is ahead,” so to speak). To avoid this problem, it is important that the length of any study be specified in advance or at least prior to any examination of the data.

Another form of data selection occurs when only significant results are published or selected for analysis, with insignificant studies being ignored.  This form of data selection has long been a standard allegation of the critics.  Alcock (1981) for instance charges that parapsychologists only tend to publish significant studies, intimating that the overall evidence for psi might be due to this type of data selection.  In rebutting Alcock, Stanford (1982) notes that the Parapsychological Association has long had a policy of encouraging the publication of nonsignificant studies, and indeed it does appear that negative results have been published with greater frequency in recent years.  To gauge the extent of selective reporting in one specific area of psi research, Blackmore (1980) sent a questionnaire to members of the Parapsychological Association asking about unpublished ganzfeld studies.  She uncovered 20 such studies, 37 percent of which were significant, as opposed to 57 percent of published studies. (One of the twenty studies could not be evaluated as to significance.)  A statistical test indicated this slight difference in success rate between published and unpublished studies was not statistically significant.  Thus, selective reporting does not appear to be a major problem in this area of research.  Also, the high significance levels obtained in some parapsychological studies argue against a data selection explanation for those particular results. If an experimenter obtains an ESP scoring rate in his study that would only be expected to occur in one in a billion such studies by chance, we may conclude that the result is not due to data selection, as it would be absurd to assume that a billion such studies have been conducted and have gone unreported.

Also, using the technique of meta-analysis (to be discussed below) it is possible to estimate the number of nonsignificant studies that must have gone unreported in order that a particular line of experimentation might be attributed to data selection.  Often the number of unpublished studies that must be postulated is unreasonably high, as we shall see.

The Problem of Fraud.  One reason for critics’ reluctance to accept the experimental findings of parapsychologists is the possibility that they may be the result of fraud, either by subjects or by the investigators themselves. We will discuss each in turn, beginning with the former.

Fraud by Subjects. In certain types of parapsychological experiments, fraud by subjects is a possibility that must be carefully guarded against. This is especially true of experiments employing “special subjects,” a term used to designate persons with a reputation for having extraordinary paranormal abilities and whose livelihood often depends on the exhibition of such abilities. Subject fraud is much less of a concern in situations in which a group of supposedly average citizens participates in an experiment initiated and designed by the parapsychological investigator, although even in this type of experiment it is prudent to take precautions against the possibility of deceit by subjects.

Several instances of subject fraud occurred in the very early investigations of “mind-reading” teams.  Hansel (1966, 1980) describes how such fraud occurred in the Society for Psychical  Research’s (S.P.R.s) investigations of the mind-reading team of Douglas Blackburn and G. A. Smith, which were conducted over the time period from 1882 to 1894.  Blackburn served as the telepathic agent in a series of apparently successful picture-drawing experiments in which Smith was the receiver.  Blackburn confessed in 1908 that these results had been due to fraud. He as agent had transferred the target drawings onto cigarette paper and then was able to get this paper to Smith when Smith reached for his pencil.  Smith himself never admitted to his involvement in the fraud.

The subjects in another one of the S.P.R.’s investigations, the Creery sisters, likewise admitted six years after the investigation that they had used auditory and visual codes to transmit the identity of playing cards to one another. (Gurney, 1888-1889).  Similarly, Hansel (1966, 1980) describes how two Welsh schoolboys, Glyn and Ieuan Jones, used signals involving coughs and leg movements to transmit the identity of cards from one to another during experiments run by the British parapsychologist S. G. Soal and his coworkers.  The alleged telepathic effects ceased when the door joining the boys’ rooms was closed, illustrating the importance of eliminating the possible use of sensory codes by members of alleged mind-reading teams. This is of course merely a special case of the elimination of sensory cues, which is a necessary feature of any properly designed parapsychological experiment.

Hansel (1966, 1980) has also charged that the results of the Pearce-Pratt experiment with Zener cards, discussed earlier in the chapter, were due to subject fraud.  Specifically, Hansel proposes an implausible scenario that involved Pearce’s sneaking out of the library and peering through the transom at the top of the door to Pratt’s room to learn the identity of some of the cards as Pratt recorded the order of the target deck.  In presenting his hypothesis, Hansel distorted the architectural plan of the building in which Pratt was located, as has been pointed out by Stevenson (1967).  Also, the rather obvious possibility of detection would surely have acted as a strong deterrent to such a scheme. Nevertheless, the fact that Pearce’s whereabouts were not well monitored renders this experiment less than definitive.  Irwin (1994) has argued that declines in Pearce’s scoring rates over the course of each session that were discovered after the experiment was concluded, are further evidence for the authenticity of the data, as such decline effects are commonly observed in ESP scoring.  A determined skeptic could of course argue that these decline effects may be due to subjects’ tendency to cheat early in a session and then “rest their case.”

Subject fraud becomes a central concern in experiments on “macro-PK.” Macro-PK experiments involve the production of macrophysical effects, as opposed to subtle influences on random event generators that may only be detectable through statistical analysis.  Such macrophysical effects include the bending of metal specimens, the levitation or anomalous movement of macrophysical (that is, nonmicroscopic) objects, the starting or stopping of watches, and the apparently paranormal production of photographs.  Macro-PK experiments typically but not always involve “special subjects” (persons with prior reputations regarding their ability to manifest extraordinary physical effects of an apparently paranormal nature).  It is of course quite possible that such subjects may use fraudulent means to simulate paranormal effects, and it is thus very important that every precaution be taken to eliminate the possibility of such fraud. Unfortunately, macro-PK experiments have frequently lacked the kind of rigorous conditions that would enable the fraud hypothesis to be definitively ruled out.   For instance, in the research on metal-bending conducted by physicist John Hasted (1981), the subjects were allowed physical contact with the target object.  One subject, Masuaki Kiyota, was even allowed to carry a spoon he was attempting to bend psychokinetically around with him in his pocket.  Such lax conditions allow the subjects the opportunity to bend the metal specimens through covert muscular action.  Hasted eschewed the use of a video camera, as he felt that such a device with its implied mistrust would decrease his rapport with the subject.

  Martin Gardner, the noted writer of popular books on mathematics and a staunch critic of parapsychology, has criticized macro-PK researchers for their failure to employ traps such as a one-way mirror to detect cheating (Gardner, 1986).  That such devices may be effective in detecting fraud is borne out by the research of Pamplin and Collins (1975), who used a one-way mirror to observe several young subjects using fraudulent means to bend metal specimens.

James Randi, who is a professional magician as well as being a prominent critic of psi research, sent two young magicians to a parapsychological laboratory in St. Louis to pose as special macro-PK subjects in an operation Randi (1983a, 1983b, 1986) dubbed “Project Alpha.”  Randi found that the researchers had ignored his own advice as to what precautions should be taken against subject fraud.  Objects were marked with tags that could be switched.  The subjects were allowed to handle sealed envelopes containing ESP targets when they were alone and unobserved.  They were able to remove the targets and return them, replacing the staples on the envelope.  They were able to remove metal specimens and other target objects from containers supposedly designed to prevent their removal.  They were also able to introduce a gap in the sealing of a bell jar, allowing movement of a rotor inside to be produced through air puffs.

Another area in which subject fraud has frequently been charged is that of psychic photography or “thoughtography,” in which a psychic is allegedly able to impress his mental images directly onto film, often through a sealed camera or a camera in which the lens has been removed.  Several investigations of thoughtography have been reported by Jule Eisenbud and his coworkers (e.g., Eisenbud, 1967, 1977a, 1977b, 1982b; Eisenbud, Pratt & Stevenson, 1981).  Eisenbud’s most prominent subject was Ted Serios, an alcoholic who was consistently intoxicated throughout the experiments and often insisted that the other people present at the experimental sessions drink with him.  A party atmosphere often prevailed, with many people milling about.  Needless to say, this did not make for the best observational conditions.  Serios used a “gizmo,” a cylindrical device that he held up to the camera when the pictures were taken. Many skeptics have contended that this gizmo provided Serios an opportunity to engage in sleight-of-hand, such as by secreting a photographic transparency and lens in the gizmo.  A gizmo-like device was also used by another of Eisenbud’s subjects, stuntman Willie Schwanholz.  It is also unclear in many of the experiments how closely guarded the camera and filmpacks were during the sometimes lengthy proceedings.  Another subject, the aforementioned Masuaki Kiyota, was allowed to take the camera in the room by himself and to unload the film by himself.

Thus, it is clear that investigations of special macro-PK subjects have all too often fallen short of ideal standards of rigor and sometimes lack necessary precautions against subject fraud.  It is important that the control of experiments reside with the experimenter; the subject simply must not be allowed to dictate conditions to the extent that all precautions and safeguards are abrogated.

Akers (1984) cited 12 of his 54 experiments for allowing the possibility of subject fraud.  Again, subject fraud is not usually so great a concern in experiments involving unselected subjects as it is in experiments with special subjects.

Experimenter fraud. There remains the possibility that the experimenters themselves might engage in fraud. Certainly, some parapsychological researchers have been caught red-handed in such activity.  Experimental studies of telepathy by S. G. Soal (Soal & Bateman, 1954), long regarded as among the studies providing the most impressive evidence for ESP, have been demonstrated through statistical analyses by Scott and Haskell (1974) and a computer analysis of Soal’s target series by Markwick (1978) to be due to a crude form of fraudulent alteration of the experimental data by Soal.

The second major scandal involving investigator fraud in parapsychology involved Walter J. Levy, a young medical school graduate, who had recently been appointed as director of J. B. Rhine’s research institute and whom many people regarded as Rhine’s heir-apparent.  When I joined Rhine’s research staff in 1974 shortly after completing my own doctorate, one of the primary things that lured me to the lab was Levy’s active and hugely successful program in investigating the psi powers of animals, including the precognitive abilities of jirds (a fancy name for what are essentially gerbils) and the psychokinetic powers of rats and chicken embryos.  The hapless little jirds had to use their ESP to avoid getting zapped by an electrical shock by moving to the part of their cage or exercise wheel that was would be spared the electricity.  The chicken embryos (still of course encased in their eggs) had to use their PK powers to get a random event generator (REG) to turn on a light to warm them up in lieu of a hen.  The rats had to use their PK to convince an REG to send them a jolt in the pleasure center of their brains. It was this last experiment that proved to be Levy’s undoing.  His fellow researchers noticed him frequently puttering around the equipment when experiments were in progress and there would normally be no reason to be interacting with the experimental apparatus.  To see if he were up to some monkey business, they secretly wired up the computer to make a duplicate record of the output of the REG. This second record showed the output of the REG to be perfectly random, while Levy’s official record showed that the rat was getting jolt after jolt to his pleasure center and obtaining truly prodigious PK scores in the process.  It transpired that Levy was disconnecting the wire that recorded the trials on which the rat was unsuccessful and shorting it out on the side of the computer for brief periods of time, thus making it seem as though the rat was achieving remarkable PK success.  Confronted with the evidence of his crimes, Levy was forced to resign as the director of Rhine’s lab and returned to the practice of medicine.

Some critics, including Hansel (1980), have alleged fraud in a great many other investigations.  Hansel provides lengthy analyses of experiments showing how significant results could have been produced by fraud on the part of one or more members of the investigating team. His postulation of honesty on the part of some of the participants increases the fun of his analyses, but of course any significant result could be the result of collusion on the part of everyone concerned.  Occasionally, Hansel goes somewhat overboard, such as when he fishes through the data of the famous Pratt-Woodruff experiment (Pratt & Woodruff, 1939) until he finds an anomalous pattern in the data and then proceeds to use that pattern as evidence for a fraud hypothesis—a hypothesis that was itself undoubtedly constructed on the basis of the pattern in an ex post facto manner (although Hansel does not present it that way). Such flagrantly circular reasoning and unwarranted inferences from post hoc analyses are no more appropriate when they are employed by a skeptic like Hansel than when they are employed by the parapsychologists he criticizes.  

It should be borne in mind that parapsychology is by no means unique in having had investigators exposed in fraudulent activity. Few areas of science have escaped the problem of experimenter fraud, as is evident to anyone reading the pages of Nature and Science over the past few decades.  For a good discussion of the problem of fraud in more orthodox areas of science, see Broad and Wade (1982) and Kohn (1986).  As these authors note, even such great scientists as Galileo, Newton and Mendel apparently succumbed to the temptation to fudge their data from time to time.  It must stand to parapsychology’s credit that the major instances of fraud in parapsychology have been unearthed by the parapsychologists themselves.  Like most areas of science, parapsychology is self-policing and most parapsychologists wish simply to get at the truth underlying ostensible psi phenomena rather than having any dogmatic pro-paranormal ax to grind.  Even archskeptic Martin Gardner has stated that he believes that such cheating by experimenters is not much more of a problem in parapsychology than it is in more orthodox areas of science (Gardner, 1986).  However, in view of the fact that most investigators are not able to obtain reliable and replicable experimental evidence for psi, the possibility that the most striking evidence for psi is due to experimenter fraud should not be completely discounted.  If such is the case, parapsychology would stand head and shoulders above the typical run-of-the-mill case of experimenter fraud in terms of the large number of investigators and studies involved.  It would be fraud on a scale that is unprecedented in the history of science.   But then again, the phenomena that are claimed to occur by parapsychologists constitute an anomaly with implications that are also unprecedented in terms of the magnitude of the revision in existing scientific theories and indeed in the basic world view of contemporary scientists that would be required in order to accommodate them, as will become apparent in the next chapter.   It may not be surprising that most orthodox scientists opt for an explanation of psi in terms of widespread experimenter fraud and incompetence, in that the hypothesis of experimenter malfeasance/incompetence constitutes the lesser of the two horns of the dilemma that faces them in terms of sheer incompatibility with their existing worldview.   

One method of minimizing the possibility of experimenter fraud, which was endorsed by J. B. Rhine, is to run experiments in such a way that the integrity of the procedures and data is under the control of several observers.  Experiments can (and have been) designed in such a way that no one member of an investigating team could fraudulently generate a significant result. In such experiments, a determined skeptic would have to postulate a conspiracy among all the members of the investigating team, which is of course much less plausible than the allegation of fraud against a single person.

Psi-mediated experimenter effects. It is certainly true that some investigators seem to be able to obtain significant psi effects on a fairly regular basis, while other investigators (including the author) almost never obtain significant evidence of psi despite years of prodigious effort spent in the laboratory.  Experimenter fraud is of course one possible explanation for this state of affairs. Another possibility is a difference in personality traits and social interaction style between so-called “psi-facilitory” and “psi-inhibitory” experimenters.  J. B. Rhine, for instance, contended that it takes a great deal of skill, personal warmth and enthusiasm on the part of an experimenter to elicit psi from subjects in a laboratory situation.  A third possibility, suggested by Jim Kennedy (a member of the research team that exposed Levy) and Judy Taddonio among others, is that the “psi-facilitatory” experimenters are themselves the real source of psi in their experiments (Kennedy & Taddonio, 1976; Kennedy, 1994, 1995).  In their view, such experimenters might subconsciously use their own psi powers to generate significant results, such as “PK-ing” extraverts to score above chance and introverts to score below chance in an ESP test in order to confirm a pet hypothesis, or by using their precognitive powers to select an appropriate entry into a random number table to ensure that the targets will coincide with the subjects’ guesses.  For instance, Helmut Schmidt (1970) once ran an experiment to see if cockroaches could use their psychokinetic powers to avoid getting electrical shocks.  Instead, he found that they got more shocks than they would have been expected to by chance.  Does this mean that cockroaches are masochistic?  Not necessarily.  It seems that Schmidt may have rather enjoyed the sight of the cockroaches popping up from their grid floor like so much popcorn whenever a shock was delivered.  Thus, he may have been the real source of the PK effect.

Some studies (e.g. Parker, 1977, and Sargent, 1980) have shown that psi-facilitating experimenters outperform psi-inhibiting experimenters in tests of their own psi ability.  There is even evidence that the person who tabulates the data of an experiment after it has been completed may influence the outcome of the experiment (the “checker effect”), possibly through the use of retroactive psychokinesis (see Weiner & Zingrone, 1986, and White, 1976) for a review of such evidence.  Some writers, including Millar (1978), have suggested that psi ability may be comparatively rare in the population and that successful experimenters may represent some of the few available “psi sources.”  Of course, if these psi-facilitating experimenters are using their own psi abilities to force the data to conform with their own theories, it would be wise to be cautious about such experimental “confirmations” of hypotheses.

The repeatability problem. One of the reasons why parapsychology has not been embraced by the scientific establishment is that many or most researchers have been unable to obtain reliable evidence of psi.  In the critic’s mind, this raises the suspicion that the evidence for psi may be due to undetected methodological errors or possibly even fraud on the part of the experimenters.  Parapsychologists have been quick to point out that many naturally occurring phenomena, such as ball lightning and meteorite landings, are not reproducible on demand but are nonetheless real.  (Interestingly, both ball lightning and meteorites were initially disputed by many scientists in much the same way as current scientists reject psi phenomena or, for that matter, cryptozoological phenomena such as Bigfoot sightings). 

Some psi proponents suggest that the mere presence of a skeptic may inhibit the manifestation of psi, in a kind of reverse psi-mediated experimenter effect.  The noted physicist A. J. Leggett (1987b) has described the principle of the repeatability of observations in science as the “no ghost” hypothesis (that is, that scientific results are not dependent on the presence or absence of certain observers or on the mental state of the observer).  This is a not-so-veiled jab at parapsychology.  David Ray Griffin (1988a), on the other hand, contends that the repeatability problems of parapsychology are due to the fact that “purposive elements” do not behave with same regularity as the billiard balls of Newtonian physics.  Indeed, results in the field of orthodox psychology are rarely as repeatable as are well-established findings in physics.

Beloff (1984) has concluded that “strict repeatability” (“repeatability by any competent observer who adopts the prescribed procedures”) is what is needed to convince the critics of the validity of psi.  Beloff contends that one form of repeatable observation would be the examination of a film of a strong macro-PK performance or of a “permanent paranormal object” (PPO), such as two interlocked rings of differing composition (e.g., different types of wood).  Beloff notes that precisely the latter form of evidence was allegedly produced by the medium Margery in the 1930s, although the rings later became mysteriously unlocked.  Possibly in response to Beloff’s call, Wälti (1990) reported the existence of a PPO, consisting of two interlocked frames of paper and aluminum that was presented to Wälti by the psychic Silvio Meyer.  Archskeptic Martin Gardner has, however, discussed methods suggested to him by his readers whereby Meyer might have fraudulently produced the object.  One of the methods involved manufacturing the paper square around the aluminum frame (Gardner, 1991).  

Meta-analysis. Recently a statistical technique known as “meta-analysis” has played an extraordinarily active role both in parapsychological research and debates about the reality of parapsychological effects.  A meta-analysis consists of a statistical examination of a group of experimental studies, sometimes consisting of an entire line of research, in order to determine the strength, direction and statistical significance of any overall effects as well as the possible influence of moderator variables (e.g., barometric pressure or the sex of the experimenter) on the size and direction of the effect in question.

One of the earliest uses of meta-analytic techniques was in the now classic debate over the significance and replicability of the ganzfeld line of research between the parapsychologist Charles Honorton and the critic Ray Hyman (Honorton, 1985; Hyman, 1985). Since that time, meta-analyses of a great many lines of parapsychological research have been reported, including forced-choice precognition experiments (Honorton & Ferrari, 1989), free-response ESP experiments (Milton, 1993), bio-PK studies (Braud, 1985; Braud, Schlitz & Schmidt, 1990; Walach & Schmidt, 2005), PK experiments with REGs (Radin, May & Thomson, 1986; Steinkamp, Boller and Bösch, 2002; Pallikari, 2004; Jahn & Dunne, 2005; Ehm, 2005), PK experiments with dice (Radin & Ferrari, 1991), and experiments investigating the effects of hypnosis on ESP (Schechter, 1984; Stanford & Stein, 1994), studies with subjects recruited via the mass media (Milton, 1994), the relationship between ESP scores and the psychological trait of defensiveness (Watt, 1991; Haraldsson & Houtkooper, 1994), the relationship between ESP and extraversion (Honorton, Ferrari & Bem, 1990), and detection of being watched over a closed television circuit monitor (Schmidt, Schneider, Utts & Wallach, 2004), to name just a few.

Among other things, meta-analysis offers a means of deciding whether a given line of research has produced overall results that differ significantly from what would be expected by chance.  For instance, in a vote-counting type of meta-analysis (that has now gone out of fashion), Radin, May and Thomson (1986) analyzed 332 PK experiments with random event generators that had been published between 1969 and 1984, finding 71 of them to have produced statistically significant evidence of psi. They compute the probability of this happening by chance to be less than 5.4 x 10-43

Meta-analysis also provides a means for answering the charge of data selection. For instance Radin, May and Thomson compute that, in order to reduce the overall REG-PK effect to nonsignificance, it would have to be assumed that 7,778 nonsignificant studies had been conducted but not reported..

Similarly, Honorton (1985) performed a meta-analysis of 28 ganzfeld studies and concluded that, in order to reduce the cumulated ESP effect to nonsignificance, it would have to be assumed that a “filedrawer” containing 423 nonsignficant and unpublished studies would have to exist into order to reduce to overall ESP effect to nonsignificance.

The traditional “filedrawer” computation in meta-analysis assumes that the overall chance distribution is replicated in the unpublished studies in the filedrawer.  Scargle (2000) has noted that this assumption may be invalid, in that if all the positive, statistically-significant studies are published, the file drawer will consist of studies that do not fall in the upper “tail” of the distribution.  Hence, the average psi effect in the studies in the filedrawer will tend to be slightly negative rather than zero as assumed in the traditional filedrawer calculation.  Stokes (2001) performed a Monte Carlo analysis and determined that if one takes 90 ganzfeld “pseudoexperiments” simulated using random numbers to simulate chance performance and then selects the 28 highest experiments, the odds against chance for the 28 highest experiments will be more than one billion to one (as found in Honorton’s meta-analysis).  Thus, one would only have to assume the existence of 62 unpublished studies, rather than 423 studies as computed by Honorton (1985).  While it stretches the mind to think that there are 423 unpublished ganzfeld studies given the small size of the parapsychological research community, it may not be so unthinkable that there are 62 unpublished studies.

As a way around the filedrawer problem, Bösch (2004) suggested that psi experiments be preregistered before the data collection process.  Kennedy (2004) proposes that parapsychology adopt the standard used in the pharmaceutical industry (in which Kennedy works) and that research protocols be developed and registered and calculations of statistical power (the ability to detect an effect of the predicted size) be performed prior to the data collection process.  Kennedy questions the value of post hoc meta-analyses in that meta-analyses may be manipulated to produce a desired outcome (such as when a judgment of study quality is made after the results of the study are known.)

Statistical calculations can go a long way toward settling the question of whether the significant results reported in a line of research could have arisen by chance or as a result of data selection.  There are, however, other ways significant effects could arise and still not be due to psi. Procedural errors and fraud are two possibilities. What might satisfy the critics would be something approaching repeatability upon demand. If virtually anyone could produce psi effects under conditions he or she found acceptable, there would certainly no longer be much debate about their reality. Perhaps, if a certain minimal proportion of all investigators could obtain evidence of psi, then the critics would be satisfied. Or possibly, if certain individual critics obtained evidence for ESP, the battle for the acceptance of psi would be won. Replication may well be at heart a political process rather than an issue that can be decided by statistical analysis.


After the review of the evidence for psi in these past two chapters, the reader undoubtedly finds himself or herself in the position of a spectator in a 125 year long prize fight.  The skeptics have delivered a few good blows, perhaps even a few knockdowns.  They are likely ahead on points.  Both sides are glassy-eyed. But the parapsychologists sit in their corner, apparently more than ready for yet another round.  Nothing is certain and the skeptics’ chin still reels the invisible blow that knocked my student’s father off his park bench and other phenomena that cannot be so easily explained by normal processes.

   The existing evidence does not compel the conclusion that psi phenomena exist.  The determined skeptic who wishes to ascribe all the experimental evidence to a combination of experimenter incompetence, methodological errors and outright fraud can rest easy knowing that, given the poor replicability of psi results, his or her position will not easily refuted.  However, to attribute the existing evidence for psi is to such factors is to postulate a level of experimenter malfeasance/incompetence that is unparalleled in the history of science.    

 Spontaneous phenomena may also be explained away in terms of memory distortions, embellishments, runaway fantasies, coincidence, psychosis, and outright falsification and collusion on the part of the witnesses involved.  Again the skeptic can rest easy, knowing that such attributions cannot easily be disproved.  The case for psi has not been conclusively established.  Conclusive proof will likely await the development of repeatable means of eliciting psi.

 Like many self-professed skeptics I have conversed with, I find the evidence from spontaneous cases perhaps the most convincing.

 My graduate adviser in psychology at the University of Michigan, aware of my dismayingly growing interest in psi research in the early 1970s, stated that he didn’t dispute the reality of psi phenomena but questioned their importance.  Perhaps that is because the major implications of psi phenomena lie in the area of our understanding of spacetime and the mind’s role in the physical universe, normally more the concern of physicists and philosophers rather the falling within the narrowly focused world of the experimental psychologists that constituted my social milieu in graduate school.

 If psi phenomena exist, their implications for our fundamental understanding of the nature of reality are profound.  These implications form the subject of the next chapter.

 It should be stressed, however, that the nonexistence of psi would not alter in any important way the core conclusions put forth in these pages regarding the fundamental nature of the conscious self, its interactions with the physical body, its likely central role in the causation of physical phenomena, and its likely survival of the death of the physical body as outlined in Chapter 0 and in later portions of this book. 

5. The Implications of Psi

 If psi phenomena exist, they likely have major implications for our understanding of the role of mind in the physical universe, of the nature of the interaction between the mental and physical realms (if these in fact are separate realms), and of the very nature of time and space.  

This chapter is devoted to an examination of the various theories that have been proposed to explain psi phenomena.  Some attempts have been made to explain psi phenomena in terms of the classical Newtonian physics that implicitly underlie the metaphysical mindset of the majority of the “orthodox” scientific community (with the exception of the physicists themselves, of course).  In general, these attempts have not met with success.  Other attempted theories involve extensions of our current views of space and time and quantum mechanics.  A third genre of theories proposes the existence of a collective unconscious or collective mind. We will consider each of these theoretical genres in turn.

No one theory has gained general acceptance within the parapsychological community.  As K. Ramakrishna Rao, a past President of the Parapsychological Association, has pointed out, the lack of any agreed-upon theory of psi is one reason for the general skepticism of the scientific establishment regarding the existence of parapsychological phenomena (Rao, 1977).  Indeed, some skeptics, such as Antony Flew (1989), have explicitly cited the lack of such a theory as their reason for rejecting the evidence for psi. The lack of a viable theory has hindered the acceptance of hypotheses in other areas of science as well.  For instance, Alfred Wegener’s ideas regarding continental drift were rejected for decades by the scientific community of geologists, despite an impressive array of geophysical evidence supporting them.  It was not until the theory of plate tectonics had been developed and the vast amount of physical evidence for sea-floor spreading had accumulated that Wegener’s theory was finally accepted by the majority of geologists (see Morris, 1983, for a more detailed discussion of this controversy).

Thus, a powerful theory may be what is needed if the science of parapsychology is to gain general acceptance by the scientific community.  Of course, the very elusiveness of psi phenomena makes it very difficult to test and refine such a theory.  So long as psi effects manifest themselves so capriciously in experimental situations, it will be hard to construct a well-verified theory of psi.

Characteristics of a Good Scientific Theory.

One of the commonly accepted criteria for classifying a theory as scientific (or in some circles as meaningful at all) is that the theory should make specific predictions about the outcomes of experiments or other types of scientific observations.  In other words, the theory must be capable of being proven wrong should the predictions prove erroneous.  This is the criterion of “falsifiability” propounded by the philosopher Karl Popper (1959).  Theories that do not yield any predictions regarding possible scientific observations are held to be unfalsifiable and are generally rejected as being unscientific.  A large number of “crackpot” theories have been proposed to explain psi phenomena.  These theories have invoked new fields or particles, such as “psi fields,” “psi-info waves,” “psychical fields,” “omnipotent consciousness fields,”   ”i-ther” (an intelligent form of the ether once though to be the medium for carrying electromagnetic waves) and “bioplasma” (to name but a few proposed constructs), in order to explain ESP or PK.  The authors of these theories have typically offered no reliable means of detecting or measuring their hypothetical fields, particles or energies, nor do they specify the properties of these entities in a sufficiently exact way that testable predictions can be derived from their theories.  Thus, these theories do not qualify as scientific (or even as meaningful) under Popper’s falsifiability criterion, and they will therefore not be further considered in this chapter.

Before dismissing all such theories entirely, however, it should be noted that not all scientists and philosophers of science insist on strict adherence to the falsifiability criterion.  For instance, physicist David Bohm and F. David Peat have argued that insistence on immediate falsifiability may stifle creative thought and innovation and discourage the creative playing with ideas that may eventually give rise to falsifiable theories (Bohm & Peat, 1987).  In this context, they cite Democritus’ postulation of the existence of atoms, which stood as an untestable idea for millennia before giving rise to modern theories of the atom.   

Two theories that make exactly the same predictions are said to be “operationally equivalent” and are often considered to be merely different verbal or mathematical formulations of the same theory.  (Of course, it may be a bit chauvinistic on our part to regard two theories as identical simply because they make the same predictions regarding our possible experiences.  Just because we with our limited senses and powers of investigation can’t distinguish between two theories does not necessarily mean that some privileged observer may not be able to distinguish between them. For instance, the hypothesis that reincarnation occurs but that one carries no trace of one’s previous personality or memory of one’s previous lives may be operationally equivalent for us to the hypothesis that no soul exists and that consciousness is totally extinguished at death, but to some intelligent alien capable of perceiving disembodied souls, the two hypotheses may be not at all equivalent.)

In instances in which two theories appear to be operationally equivalent, the theory that is more conservative in terms of postulating new entities and processes is usually held to be preferred over any less conservative rival.  This injunction “not to multiply entities beyond necessity” is commonly known as Ockham’s Razor (after the fourteenth century philosopher William of Ockham). Thus, if a medium becomes apparently possessed by the spirit of someone’s dead uncle and proceeds to relate accurately details of that uncle’s life, it is more conservative to assume that the medium used his or her powers of telepathy (or even better yet from the conservative point of view, fraud) to obtain this information than to postulate the existence of disembodied spirits.  This “super-ESP” hypothesis is preferred to the discarnate spirit hypothesis by most parapsychologists on the basis of Ockham’s Razor (which is ironically the same principle invoked by the skeptics to support their preference of the fraud/error/delusion hypothesis over the ESP hypothesis).

In some instances, hypotheses that at first glance appear to be unfalsifiable, and hence metaphysical rather than scientific in nature, can be rendered falsifiable through the use of an “operational definition.”  Consider the question of “consciousness” in animal and computers.  Are, for instance, dogs to be regarded as conscious?  Amoebae?  How about computers?  Or thermostats? The famous neurophysiologist W. Grey Walter constructed mechanical “tortoises,” which ambulated about his house randomly until they ran low on power, at which point they would proceed to the nearest electrical socket to recharge themselves. Were Walter’s tortoises conscious?  Did they feel a passion for communion with electrical sockets or a sense of anxiety and depression when their power became low?  As discussed in Chapter 1, in order to resolve one of these questions, the mathematician Alan Turing (1950, 1964) proposed to define a computer as conscious if it could successfully imitate a human being to the extent that a person communicating through a teletype terminal could not discriminate between the computer’s remarks and those of the human being. Turing’s “imitation game” provided a means whereby the apparently metaphysical hypothesis of consciousness in computers could be given an operational definition and become subject to scientific test.

Alternate forms of rationality.  A small minority of parapsychologists have on occasion called for a reexamination of the appropriateness of the traditional methods of science for the investigation of psi phenomena.  In some cases, they have called for the abandonment of such methods in favor of alternate forms of rationality.  Harman (1993), for instance, questions the ontological assumption of the separation of the observer from what is observed that he sees as underlying the modern scientific method. He calls for the adoption of “other ways of knowing,” such as intuition and mysticism, that are based on the assumption of an underlying “oneness” between the knower and the known.  Tart (1972) observed that different states of consciousness (such as dreaming, marijuana intoxication, and religious ecstasy) are characterized by different forms of information processing and cognition, and he called for the development of “state specific sciences,” each to be based on the form of rationality characteristic of a particular state of consciousness.  In making such suggestions, both Tart and Harman reflect a recent trend among historians, sociologists and philosophers of science to question whether there is one demonstrably correct form of rationality (see Dolby, 1979; Feyerbend, 1981; Collins & Pinch,1982; and Woolgar, 1988, for examples of this trend).  

The takeover of large parts of the academic establishment by “social constructionists” and “epistemological relativists” who deny that there is any preferred mode of knowing and who treat all theories of the world, including modern science and its pseudoscientific brethren such as flat Earth theory and fundamentalist Creationism, as “socially constructed realities” and as on an equal footing has been described in much detail by Paul Gross and Norman Leavitt in their book Higher Superstition: The Academic Left and its Quarrel with Science (Gross & Leavitt, 1994).  This movement, however, took a huge blow in the chin and was largely discredited when Allan Sokal, a professor of physics at New York University, deliberately wrote a paper entitled "Transgressing the Boundaries: Towards a Transformative Hermeneutics of Quantum Gravity" that consisted of entirely meaningless gobbledygook and submitted it for publication to the “academic” journal Social Text, a publishing vehicle for social constructionists.  Amazingly (although not to Sokal’s personal astonishment), it was accepted and published as Sokal (1996).  Along with many other nonsensical assertions in the article, Sokal contended that the psychoanalytic speculations of the radical French psychoanalyst Jacques Lacan have been confirmed by recent work in quantum field theory.  The publication of Sokal’s article was a blow from which the radical social constructivist movement has yet to recover.   

Traditional scientific methods have enjoyed a history of success in the prediction and control of nature. They have led to a convergence of thought that is unprecedented (with the possible exception of the occasional “pseudoconsensus” achieved through the ruthless exercise of religious or other authority).  Mystical insight and religious inspiration have rarely led to consensus about the nature or number of gods or the purpose of the universe.  Neither have the variant thought processes of the intoxicated or the schizophrenic led to a consistent alternative picture of realty. Of course, it may be argued that consistency is the hobgoblin of the unimaginative and that reality may not correspond to the consensus of the majority of scientists. It is also true that certain central issues have proven themselves relatively impervious to scientific investigation. Science has, for instance, no good explanation of why certain types of brain activity should be associated with or give rise to conscious experience. Neither is it able to offer an explanation of why the universe should have been created with its particular set of properties (it can only elucidate what those properties are). Thus, alternate forms of rationality may have their place and may even be necessary to address questions that are (at least at present) not answerable by science. However, if parapsychologists were to depart from traditional scientific methodology and adopt some form of alternative rationality, it is not clear that they would any longer be practicing science in any conventional sense of the term. It is clear that such action would result in the rejection of parapsychology as an unscientific enterprise by scientific establishment. This rejection would be legitimate under any standard use of the word “scientific.”

Having laid the “metatheoretic” background, we will now examine some of the theories that have been proposed to account for ESP and PK.  Theories that are primarily directed to the problem of the relationship of the mind to the physical brain—and to the possible survival of the mind (or some portions thereof) of the death of the physical body—will be addressed later in the book.

Spacetime Theories

Several theorists have invoked “warps” in spacetime or even extra dimensions of spacetime in order to explain psi.  It is for instance difficult to explain apparent cases of telepathy between two people who are separated by thousands of miles on the basis of the exchange of any known physical signal over such distances.  If it could be assumed that the people are really in much closer proximity than they seem to be due to the presence of a warp in spacetime or to a spacetime “wormhole” directly connecting them, then such long-range psi may not seem quite so problematic. Similarly, highly curved spacetimes may offer a means a getting a signal from a future event into the present, which might help to explain precognition.

“Spacewarp” Theories.  Schmeidler (1972) proposed that the universe may contain an extra dimension in addition to the familiar four dimensions of space and time that might permit the “topological folding” of spacetime to occur. As a result of such folding, two regions that appear to be widely separated in space and time might actually be very close to one another in the higher-dimensional spacetime, much as two points on a towel that are normally far apart may be adjacent once the towel is folded.

The noted physicist John Wheeler (1962), a vehement skeptic regarding psi phenomena, has proposed that at a microscopic level, quantum effects may act to produce a spacetime structure containing “wormholes” or “bridges.”  (The handle on a coffee cup might be thought of as a wormhole or bridge in the surface of the cup.)  Wheeler proposed that such wormholes might connect pairs of oppositely charged particles such as electrons and positrons, and his proposed spacetime structure is sometimes referred to as the “quantum foam.” As Parker (1991) points out, however, Wheeler’s quantum foam theory is not accepted by most contemporary physicists.  Several other scientists have speculated that such wormholes may exist on a macroscopic scale and that in some cases rotating black holes may generate wormhole tunnels to other regions of our own spacetime or even to a different universe that exists outside of the spacetime regions to which we have access.  

Wormhole theories of psi have been proposed by Schmeidler’s one-time mentor, the noted psychologist Gardner Murphy (1964) as well as by Toben and Wolf (1982), although these theories are not spelled out in much mathematical detail.  Morris (1990) points out that any attempt to travel through a wormhole or to send a signal through one will result in frustration, as the traveler or signal will emerge from the wormhole within the event horizon of another black hole, from which no escape is possible.  Morris does note that there may exist a type of wormhole, called a Schwarzschild wormhole with the property that, if one were to travel through a Schwarzschild wormhole, one might be able to avoid emerging inside a black hole.  It is, however, extremely doubtful that Schwarzschild wormholes exist. Another loophole may be provided by J. L. Friedman’s observations that naked singularities may exist (Friedman, 1991).  A naked singularity is essentially a black hole that does not have an event horizon, so that escape would be possible from it (that is, it is an oxymoronic nonblack black hole).

In 1949, the famous mathematician Kurt Gödel (1949a, 1949b) demonstrated that Einstein’s theory of general relativity allows the existence of universes containing closed time lines.  The notion of a closed time line is perhaps best explained by a spatial analogy.  If a person were to begin walking due east and continue until she has circumnavigated the globe (obviously some water skiing would come into play), she would eventually return to her starting position, but from a westerly direction.  Similarly, in a closed time line, if one were to travel far enough into the future, one would eventually return to the present moment (via the past).

One could readily imagine the perplexing experience of a transsexual traveler traversing a closed time line in a large spacecraft.  He meets a woman who seems strangely familiar, who reminds him of his mother, but is obviously much younger.  Being of an Oedipal nature and well-vaccinated to boot, he engages in a one-night stand, during which (unbeknownst to him) he impregnates her.  Two years later he watches three consecutive transsexuals being brutally pummeled by their ex-lovers on a sleazy holovision show hosted by someone called Jerry Springer, IV, who is evidently also the mayor of Cincinnati.  He realizes at that point that he has been living a lie and that he is a woman trapped in a man’s body.  He has the newest, most advanced form of transsexual operation, which renders him a fertile woman.  Taking advantage of a rebate offer, he has them throw in a rejuvenation procedure at the same time.  A few years later, “he,” now she, meets a man at a bar who eerily reminds her of her younger self.  Being narcissistic as well as well-vaccinated, she engages in a one-night stand, during which (unbeknownst to him) he impregnates her.  Months later, she gives birth to a little boy. The birth is traumatic and she develops a white streak in her hair as a result.  As she sits in the recovery room, she catches a glance at herself in the mirror.  She recognizes her new look and realizes that she is her own mother.  She has just given birth to herself.   

If time were to be closed for the universe as a whole, everything would recur over and over again, the ultimate form of the philosopher Friedrich Nietzsche’s (1969) “eternal return.”  The universe might collapse to a black hole and bounce back in a repeat of the Big Bang.  We would all live the same lives over and over again on each iteration of the process.  The Stoic philosophers of ancient Greece in fact believed in such a doctrine of eternal cyclic recurrence, which they termed palingenesia.

Several theorists have suggested ways in which anomalous spacetime regions might allow a physical particle to traverse a closed time line and arrive at its own “past.”  The physicist Frank Tipler (1974) has proposed that a time machine could be constructed by rotating an extremely long cylindrical mass at an extraordinarily high speed, but observes that such a time machine would unfortunately collapse along its axis due to its own gravitational self-attraction before it could be put into service.  Herbert (1988) has observed that a very rapidly rotating Kerr black hole would contain a naked ring singularity that would make travel from the Kerr hole to any location in spacetime (including one’s own past) possible.  Morris and Thorne (1988) and Morris, Thorne and Yurtsever (1988) have suggested that a time machine might be produced by taking one of the two mouths of a wormhole, moving it rapidly back and forth and then returning it to the vicinity of the second mouth of the wormhole. After this process, travel through the wormhole would enable one to reach the past.  More recently, J. Richard Gott of Princeton University has proposed that closed time loops may be created when two cosmic strings hurtle past each other at a high velocity.  A rocket ship looping around both strings could arrive at its own past. Of course, the very existence of cosmic strings remains speculation at this point. Also, Gerard t’Hooft of the Institute for Theoretical Physics in Utrecht has pointed out that, if there were enough mass in the universe to construct a time machine along Gott’s lines, the universe would necessarily have to be closed (that is, would eventually collapse back upon itself due to its gravitational self-attraction). He further points out that any closed universe would necessarily collapse to a size smaller than any closed time path under Gott’s model, making the existence of a Gott time machine impossible.  Furthermore, physicist Stephen Hawking has argued that any closed time line would destroy itself by generating a feedback loop leading to the build-up of an infinite amount of energy, destroying any time machine that might be created.  Gott proposed a variant version of his theory involving a rapidly shrinking “loop” type of cosmic string, but the equations have proven difficult to solve for this case.  See Lemonich (1991), Peterson (1994) and Travis (1992) for a discussion of the controversies surrounding Gott time machines.

If closed time lines exist, it might be possible to account for precognition in terms of a signal being emitted from the precognized event and arriving at the past by traveling along a portion of a closed time line.  

“Spacewarp” theories of psi face several difficulties.  The first is the possibility of logical paradoxes.  If I could read the winning lottery numbers in today’s paper and send them in a message to my past self via a closed time loop, I could potentially make a huge killing.  But this would entail the existence of two present moments, one in which I did not know the score and remained poor and one in which I was sent the lottery numbers and became rich.  One way around this paradox would be to deny the existence of the moments in which I did not win the lottery, perhaps postulating that the message would somehow obliterate those moments so that it would be that they never existed.  Another possibility would be to assert that the arrival of the message from my future, created two new “branches” in time, in one of which I don’t know tomorrow’s winning numbers and in one of which I do.  Branching time models are discussed in more detail latter in this chapter.  It is not clear that all closed-time loops must create logical paradoxes.  For instance, in the above story in which the man became his whole family tree, no paradox necessarily occurred.

The huge curvatures of spacetime that would be required to explain psi phenomena occurring over the typically cosmically small space-time separations involved in spontaneous and experimentally-produced psi effects would undoubtedly involve the presence of very large gravitational fields under any standard interpretation of Einstein’s theory of general relativity. For the “spacewarp” explanation to be useful, it would probably be necessary to assume, say, that the participants in a case of telepathy were in closer proximity to a rotating black hole than they were to each other.  In such a case, the gravitational tidal forces of the black hole would in all likelihood reduce a person to a molecular gas long before it conferred any paranormal powers upon him.

Similarly, the closed time lines generated in rotating universes under Gödel’s model are gigantic in size (Halpern, 1992).  Also, it is doubtful that a precognitive message could remain intact throughout the universe’s collapse in the “Big Crunch” and reemergence in a “Big Bang” or even via passage through a black hole.  However, in a well-publicized incident in 2004, famed black hole theorists Steven Hawking and Kip Thorne lost a bet to the Thorne’s Caltech colleague John Preskill, conceding that information is indeed preserved within a black hole (Rogers, 2004).  Thus, at least one barrier to information transmission through a black hole has been removed.   

Another problem is that no “spacewarp” theory of psi has been formalized and developed in such a way as to give rise to anything approaching exact predictions regarding observed psi phenomena (or indeed to any prediction not readily derived from far more accessible variables, such as psychological factors).  Nor has any method been proposed to measure the psi-inducing spacewarp.  Thus, at the present time, there is no true spacewarp theory of psi.  There are only suggestions by various authors that it might be possible to construct such a theory using such concepts as wormholes, closed time lines and extra dimensions of spacetime.  Until such a formalized, testable theory is constructed, the concept that psi phenomena may involve “spacewarps” remains only an intriguing speculation.

Multidimensional Spacetime Models. Several parapsychologists have proposed spacetime models with additional dimensions beyond the usual four in order to explain psi phenomena. The postulation of additional dimensions is one way to avoid the large gravitational fields required to produce wormholes and large curvatures of spacetime in standard interpretations of Einstein’s theory of general relativity.  Schmeidler’s postulation of an extra dimension of spacetime in order to permit “topological folding” to occur is essentially a theory of this type. The postulation of extra dimensions of spacetime may no longer be the radical move it once was, as physicists nowadays think nothing of toying with as many as 11 spacetime dimensions in “supersymmetric” theories of gravity.  However, most of these dimensions are thought to be curved so severely that they become microscopic circles that are not noticeable at a macroscopic level; thus such dimensions do not provide a means of conveying a psi signal over macroscopic distances.

Hart (1956, 1965) proposed that the material universe is a cross-section of a five dimensional manifold.  Smythies (1994, 2000, 2003) postulates the existence of three spatial dimensions and three additional spatial dimension to account for each conscious observer’s phenomenal space (space of mental imagery), resulting in 3n + 3 spatial dimensions altogether, where n is the number of conscious observers.  However, as Chari (1977) noted long ago, in both Hart’s and Smythies’ models the “extra” dimensions have not been sufficiently formalized (i.e., no noncircular method of measuring them has been proposed) to enable scientific predictions to be drawn from them, so these theories must be regarded as untestable (and hence not scientific) in their present state of development. 

Two versions of what is essentially the same multidimensional theory of spacetime have been proposed apparently independently by the team of Russell Targ, Hal Puthoff and Ed May (1979), and by physicist Elizabeth Rauscher (Rauscher 1979, 1983a, 1983b; Ramon & Rauscher, 1980).  Targ, Puthoff and May state that they developed their model in collaboration with Gerald Feinberg. (Feinberg is a physicist well known for his postulation of tachyons, particles that move at a speed faster than light, as will be discussed in more detail below.)  Both theories posit eight dimensions of space and time, although Rauscher proposed an alternative model employing six dimensions. In their latest collaborations, Rauscher and Targ (2001, 2002) propose an eight-dimensional model.  Essentially what they propose is that events that seem to be widely separated in space and time may in fact be quite close together in the higher dimensional space. 

Some background may be in order here.  If two spacetime locations (events) are separated by distances of dx1, dx2, and dx3 in the three spatial dimensions, the spatial distance separating the events is √ (dx12 + dx22 + dx32).  If c is the speed of time and dt is the length of a time interval, then the distance that can be covered by a photon (particle of light) in dt is c X dt.   In Einstein’s theory of relativity, the spatial separation and time interval between two events are dependent on the observer’s state of motion.  However, one quantity that is independent of the observer’s state of motion is the spacetime metric, given by the equation:

ds2  = dx12 + dx22 + dx32 - c2 dt2                                                  (5.1)

The spacetime metric is thus equal to the square of the spatial distance between two events minus the square of distance that can be traveled by a photon in the time interval between the two events.  If the spacetime interval is negative, then the spatial distance between the two events is less than the distance that can be traveled by a photon in the time interval separating the two events.  In this case, the events are said to be “timelike separated” and it is possible to send a causal signal (e.g., physical particle) from the early to the later events (all known causal signals travel at the speed of light or slower in conventional theories of physics).  If the spacetime metric is positive, then the spatial distance separating the events is greater than the distance that can be traveled by a causal signal whose speed is less than or equal to the speed of light.  In this case, two events are said to be “spacelike separated.”  No conventional causal signal can travel from one event to the other if the events are spacelike separated.  It is thus impossible for one of the events to be the “cause” of the other. 

What Targ, Rauscher and their coauthors (TRMPR) propose is that ordinary four-dimensional Minkowski spacetime may simply be the real part (in the mathematical sense of real numbers) of an eight-dimensional complex Minkowski spacetime (in the sense of having complex numbers as coordinates rather than real numbers).  In this model, each spatial coordinate xk would be replaced by a complex coordinate xk + xki, where i is the “imaginary” square root of -1.  Similarly the time coordinate t would be replaced by the complex coordinate t + t’i.  Equation (5.1) would be replaced by the following equation:

ds2  = dx12 + dx’12 + dx22 + dx’22 + dx32 + dx’32 - c2 (dt2 + dt’2)              (5.2)                                 

TRMPR explain long-distance ESP on the basis that, by a suitable adjustment of the imaginary coordinates, the spacetime metric ds2 can be made to be negative between any two events and thus the events become timelike separated in the spacetime with complex coordinates. (Recall that in the ordinary theory of relativity, casual signals cannot be exchanged between spacelike separated events, although they can be exchanged between events with timelike separation.)  Because they are timelike separated in this higher dimensional space, the two events would have zero spatial separation in some reference frame, although they would be separated by a longer “time” interval (when measured as the square root of dt2 + dt’2) than they were in ordinary spacetime.  

There is thus a price to pay for reducing the spatial separation to zero.  Similarly, in terms of precognition, through a suitable adjustment of the imaginary coordinates, the spacetime metric ds2 can be made to be positive so that the two events are spacelike separated in the higher dimensional space.  Thus, due to the relativity of simultaneity in Einstein’s special theory of relativity, the events will be simultaneous for some observer, so that there is no time interval separating them for such an observer.  It should be noted that despite TRMPR’s assertion that the spatial distance between two events can be reduced to zero for some observer in the higher dimensional system, this is accomplished at the price of increasing the time separation.  Similarly, reducing the time interval to zero between two events comes at the price of increasing the spatial separation between them.  The spatial and temporal intervals between two events that are separated in normal four-dimensional spacetime cannot both be reduced to zero in eight-dimensional spacetime.  Thus, two events that are separated in normal four-dimensional spacetime cannot be “brought together” in TRMPR’s eight-dimensional spacetime.  In fact, in a mathematical sense, the spacetime separation between two events can only be increased in TRMPR’s model.  

This problem could be avoided by, say, the introduction of a fourth spatial dimension x4 and one extra time dimension t2 (in addition to the “usual” time dimension t1) whose coordinates are pure imaginary numbers.  The spatial and temporal separation would then be purely imaginary numbers of the form dx4 i and dt2 i, where i is equal to √(-1).  The equation for the spacetime interval would then become: 

 ds2  = dx12 + dx22 + dx32 - dx42 - c2 (dt12 - dt22)                                (5.3)                                    

Now by adjusting the values of dx4 and dt2, the spatial and temporal distances between any two events could be adjusted to zero at the same time and thus the events could be “brought together” in the higher dimensional spacetime.

As TRMPR propose no means of measuring an object’s coordinates on their new dimensions, they are free to adjust these coordinates as they please to make things come out right. As the theory seems to be capable of explaining anything, it should be regarded as unfalsifiable and not worthy of consideration as a serious scientific theory.  (The same remarks apply to Equation 5.3, which I have just presented, as I have not suggested any means of measuring the separations between two events on the fourth spatial and second time dimensions.)  Walker (1981) has also noted that, assuming the inverse square law for gravitation is to be extended to the eight-dimensional space proposed by TRMPR, then the effects of these extra dimensions on planetary trajectories should have been long ago observed.    

One writer who has expressed a virtually mystical enthusiasm for the possibility that the mysteries of the mind and psi might be explained in terms of higher dimensional space is the mathematician and sometimes science fiction writer Rudy Rucker. In his book The Fourth Dimension (Rucker, 1984), he reviews the history of the use of higher-dimensional models to explain psi phenomena and mystical experiences.  He notes that the seventeenth century philosopher Henry More postulated that spirits are four-dimensional beings.  He also cites J. C. F. Zöllner’s experiments with the medium Henry Slade, who was supposedly able to tie a knot in a closed loop of string by transporting it to a higher dimensional realm (Zöllner, 1901).  Zöllner further proposed that a miraculous object such as interlocking rings composed of different types of wood would provide evidence of the existence of a higher dimensional reality.  It will be recalled that John Beloff has also contended that such a “permanent paranormal object” might provide convincing evidence of the reality of psi phenomena, if not of higher dimensional realms (Beloff, 1984).

Rucker himself takes an almost mystical view of higher dimensional geometries. He seconds Ouspensky’s suggestion that dreams may afford a glimpse into our four-dimensional nature (see Ouspensky, 1912/1970, 1931/1971).  Rucker suggests that seemingly separate individual persons may simply be parts of a higher unity, much as five seemingly independent circles on a two-dimensional plane may be the cross-sections of the fingers of a single three-dimensional hand.

Models of Time.  There are quite a few spontaneous cases on record that seem to indicate that one can foresee an unpleasant event in the future and then perform some action to avoid that event.  Thus, it seems that one might be able to change the future.  This raises interesting philosophical and scientific questions about the nature of time.  Louisa Rhine (1955) published a collection of such cases, and we will consider two of her cases here to give the reader a better sense of nature of such experiences. The first case is taken from her book Hidden Channels of the Mind:

In Washington State a young woman was so upset by a terrifying dream one night that she had to wake her husband and tell him about it. She had dreamed that a large ornamental chandelier which hung over their baby’s bed in the next room had fallen into the crib and crushed their baby to death. In the dream she could see herself and her husband standing amid the wreckage. The clock on the baby’s dresser said 4:35. In the distance she could hear the rain on the windowpane and the wind blowing outside.

But her husband just laughed at her. He said it was a silly dream, to forget it and go back to sleep; and in a matter of moments he did just that himself. But she could not sleep.

Finally, still frightened, she got out of bed and went to the baby’s room, got her and brought her back. On the way she stopped to look out the window, and saw a full moon, the weather calm and unlike the dream. Then, though feeling a little foolish, she got back into bed with the baby.

About two hours later they were wakened by a resounding crash. She jumped up, followed by her husband, and ran to the nursery. There, where the baby would have been lying, was the chandelier in the crib. They looked at each other and then at the clock. It stood at 4:35. Still a little skeptical they listened—to the sound of the rain on the windowpane and wind howling outside. (Rhine, 1961, pp. 198-199).

In another case in Rhine’s collection, a streetcar operator braked as he approached a one-way exit in order to avoid an accident that he had dreamed about that morning.  At that moment, a truck containing the very same people who had been injured in the dream shot out into the street, having gone the wrong way through the one-way exit.

In both of these cases, it would seem that two different futures were involved.  In the first (precognized) future, a negative event took place.  In the second future, the one that actually occurred, the negative event was avoided.

Multidimensional time models. In order to account for such cases of precognition followed by intervention to prevent the precognized event from occurring, J. W. Dunne (1938) proposed the existence of additional dimensions of time.  Dunne invoked a second time dimension (Time 2) to “clock” a person’s progress on the first, ordinary dimension of time (Time 1).  Thus, in Dunne’s theory a person is conceived of as “moving” along the Time 1 dimension and occupying later and later moments on that dimension as Time 2 elapses.

Suppose for instance that a man named Harry has a vivid dream of being killed when the giant Snoopy balloon collapses during the annual Macy’s Thanksgiving Day Parade.  Suppose, that on the basis of this dream, he cancels his annual visit to his cherished parade and goes to Fire Island instead. As his wife roasts up the turkey, he turns on the T.V. only to witness the horrible destruction as the beloved Snoopy character descends on the assembled multitude.  We could conceptualize this situation under Dunne’s theory as follows.  The future, as it existed at the moment (in Time 2) before Harry went to bed contained the event of Harry’s demise in the great Snoopy massacre, but the future after Harry made the decision to go to Fire Island (at a later moment in Time 2) did not contain his imminent death. Harry precognized the future as it existed before he took his evasive action.

There are several problems with Dunne’s theory. One major problem is that, in order to clock an observer’s progress on the second time dimension, Dunne felt compelled to invoke a third time dimension.  To clock his progress in Time 3, Dunne invented Time 4.  In fact, continuing in this manner, Dunne was forced to postulate the existence of an infinite number of time dimensions.  This is what is known as the problem of an “infinite regress,” which is usually as a sign that something is severely wrong with a theory.  This infinite regress seemed to bother just about everyone but Dunne, who was happy to talk about “the observer at infinity.”  This regress is probably a result of Dunne’s failure to employ the notion of a “timeless array” of events in spacetime rather than his dynamic model involving the “motion” of an observer along a time axis.

Some later theorists, such as C. D. Broad (1953, 1978) and D. F. Lawden (1982), tried to save Dunne’s theory by constructing models that involved “only” two time dimensions.  All these models, however, share one basic and fundamental flaw. What is to prevent someone in the past from precognizing something that we are doing now and performing an act that would pop us all out of existence?  Or perhaps we have all just been popped into existence by such an act.  If the latter is the case, we remember having lived for years, but these memories are illusory (at least in respect to our history in the second time dimension).  We have really only existed for a few seconds (of Time 2) and may be popped out of existence in a few more moments if someone in the past has a visionary experience.  It would be at least somewhat discomforting to think that our existence could be so ephemeral. One way out of this quandary might be to attempt to construct a model in which only observers at some specified coordinates in Time 1 and Time 2 would be allowed to alter the future.  This would be equivalent to defining a unique moment in time as “the present” and only allowing observers in the present to alter the future.  Unfortunately, as we shall see later, Einstein’s theory of relativity implies that there is no unique set of events called the present that is the same for all observers.  Rather, the set of events that one experiences as being simultaneous with oneself varies depending on one’s state of motion.  Unless the problems arising from this “relativity of simultaneity” could be overcome, it would seem impossible to rescue Dunne’s theory by appealing to a unique present.  

The philosopher C. W. K. Mundle (1964) points out that when Dunne speaks of precognizing “probable futures,” he is essentially abandoning his own model, which assumes that a single future exists at any given moment (of Time 2).  Thus, Dunne may himself have been striving for a model something like the branching time models to be described below.

Branching time models. In branching time models, it is assumed that at the “present” moment many possible futures exist.  For instance, in the case of the baby and the chandelier, in one possible future (the one that was precognized) the baby was killed by the falling chandelier, whereas in a second possible future (the one that actually occurred) the baby escaped injury.

In the classical, Newtonian view of the universe that prevailed until early in this century, it would be unthinkable that two different alternative futures could both be possible.  Under the Newtonian worldview, the universe was seen as governed by laws that preordained the state of the future.  This deterministic outlook of classical physics led the famous mathematician and cosmologist Pierre Simon Laplace to propose that a Divine Calculator who knew the position and velocity of every particle in the universe could deduce the entire history and future of the universe down to the last detail.

The development of the modern theory of quantum mechanics has overthrown this deterministic outlook.  Under modern theories of physics, given the present state of the universe, many different futures are possible.  An atom of radioactive material may or may not decay during a given time period.  It is impossible in principle to predict whether it will or not. Under quantum theory, different futures may have different probabilities assigned to them. For instance, it may be more likely that the above-mentioned radioactive decay will occur during the next half-hour than that it will not.

In the well-known paradox of Schrödinger’s cat, it is assumed that a cat is confined in a closed chamber that contains a cyanide capsule that will be broken if a Geiger counter registers a radioactive decay.  After a period of time, the box is opened.  Two states of the world (cat alive and cat dead) are possible, and both are compatible with the laws of physics.  (Some physicists would claim, prior to human observation, the cat is half-dead and half-alive.)   As we shall see later, the observational theories in parapsychology propose that the cat, if it may be regarded as a “psi source,” may exercise its “free will” and choose (i.e., force to occur) that state of the universe that it finds most appealing (presumably the “cat alive” state in the case on a nonsuicidal cat).  Thus, in the case of the falling chandelier, both the “baby dead” and “baby alive” futures may be compatible with the laws of physics.  Which future occurs may depend on indeterminate quantum events in the mother’s brain; if her brain enters a favorable quantum state (through precognition?), she will act to avert the disaster.

While most scientists hold that only one of the possible alternative quantum futures is actually realized, the physicist Hugh Everett (1957) has proposed that all the possible futures are actualized, albeit in alternate universes.  Everett’s theory has become known as the “many worlds” interpretation of quantum mechanics. 

The branching time model is easily capable of accommodating cases of precognition followed by intervention. One could assume, say, that in our “chandelier” case the mother foresaw the most probable future, that her baby would be killed, but was able to act in such a way as to ensure the occurrence of a less probable future.

Sondow (1984) has attempted to use a “branching time” model to explain the phenomenon of precognitive attrition (the decline in the accuracy of precognition or in the frequency of successful precognitions as the time interval between the precognitive experience and the confirming or target event increases).  Sondow provides some evidence for the phenomenon in the form of a decline in the number of her own spontaneous precognitive dreams (as recorded in a dream diary) as the interval separating the dream from the confirming event increases.  (The extent to which Sondow’s evidence and the evidence provided by other investigators supports the hypothesis of precognitive attrition will be discussed later in this chapter.)  Sondow attributes the decline in frequency (but not accuracy) of her precognitive dreams to the fact that, due to the continual branching of time lines, a greater number of alternative futures compete with the actually realized future when the time interval concerned is long than when it is short.  Sondow predicts no fall-off in precognitive accuracy with time if a single decision is used to generate a target in a precognition experiment (as the single decision will result in a single branching in time).  One might expect, however, that the probability that the probability of a target being generated would be highly correlated with (or by definition equivalent to) the number of time branches on which it occurs.  (Due to the fact that countless other quantum decisions are being made, the target will appear on many time branches rather than just one.)  Thus, one might expect the number of “true” precognition hits to be correlated simply with the probability of the target (rather than with the number of decision used to generate it) on the branching time model.

Targ and Harary (1984) report a brief and informal attempt to test the branching time model experimentally.  In a precognitive remote viewing experiment, one of six objects was randomly selected to have a 50% probability of being the target, with the remaining targets having a 10% chance of being the target.  The authors theorized that, when the 0.5 probability object was not eventually chosen as the target, it should, because of its high salience (due to its presence as target on the most probable time line), interfere with the perception of the actual target (Targ and Harary hypothesized that the most probable future will be the one most often precognized).  Because the perception of the low probability target was still accurate, even though a higher probability alternative future existed, Targ and Harary concluded that “nonactualized futures apparently do not greatly affect a viewer’s precognitive descriptions of impending events” (Targ & Harary, 1984, p.115).  However, the high probability target was selected on the basis of a die shaken but not observed prior to the remote viewing trial.  Under some interpretations of quantum mechanics (including the observational theories to be discussed later in this chapter), the state of the die is indeterminate prior to the act of observation.  Thus, it could be argued that all the targets were equally probable at the time of the remote viewing trial and therefore that no test of the alternative future hypothesis was provided by the experiment.  Also, it could be argued that this 12-trial experiment was too brief and too informal to provide such a test in any event, and that some test of the difference in “true psi hitting rates” between the high and low probability conditions needs to be provided.  Just to observe that precognition can operate in the face of a more probable alternative future is insufficient (Targ and Harary report no statistical test to demonstrate that precognition was operating in their experiment in any event).

Other branching time models have been proposed by Dobbs (1965) and Hasted (1981).  Dobbs proposes that possible futures (or “propensities”) may contact an observer’s brain through the emission of “psitrons” (particles of imaginary mass that travel backward in time), producing a precognitive experience.  Hasted proposes that paranormal metal-bending effects are brought about through “surfaces of action” that represent boundaries between alternative universes (although the standard interpretation of Everett’s “many worlds” interpretation of quantum mechanics is that alternative universe are separated in a higher-dimensional mathematical space called Hilbert space, rather than being adjacent in ordinary spacetime).  Because both Dobbs’ psitron model and Hasted’s “force surface” theory involve the propagation of signals or fields through spacetime, they will discussed later in this chapter, along with other proposed explanations of psi in terms of physical or quasiphysical signals.

Stokes (1983) used Everett’s many worlds interpretation of quantum mechanics to challenge the evidence for pure clairvoyance (direct extrasensory perception of a physical object, without involvement of telepathy).  A traditional clairvoyance experiment in which a subject successfully guesses a deck of ESP cards place faced down on a table is subject to a counterexplanation in terms of precognitive telepathy, in that the subject may be contacting the future mental state of the person who eventually inspects the targets rather than apprehending the cards directly.  It is often thought that successful experiments in which a subject guesses a hidden set of targets (perhaps existing only in a computer’s memory) and in which no one ever inspects the target sequence (the computer only prints out the final score for instance) constitutes good evidence for pure clairvoyance.  But, under a branching time model, a person might be able through precognitive telepathy to inspect the scores in several alternative futures and emit the guess sequence that occurred in a future with a high score (as information about the guess sequence would exist in the subject’s future memory in that alternative future).

The linear time model. It is also possible to account for such cases with a model postulating only one time dimension and one future, should one prefer such a pedestrian and colorless approach.  One could for instance simply state that the mother accurately foresaw that the chandelier was going to fall.  Her premonition of her baby’s death was simply an error, as that death never occurred. The mother’s unconscious mind was merely dramatizing to her the consequences of not moving the baby out from under the chandelier.

One parapsychological theorist to recently propose a linear time model is Jon Taylor (1995, 1998, 2000).  Taylor subscribes to a “block universe” model in which there is only one future, corresponding to the events that actually happen.  (Such a block universe model is also inherent in the spacetime manifold of Einstein’s special and general theories of relativity, as will be discussed in more detail below).  Thus, in Taylor’s view, it is impossible to “change the future” through an act of intervention, insofar as the future contains events that will happen, not those that might happen.  He proposes that extrasensory contacts only take place between living brains in similar emotional states, which create a “resonance” between the two brains.  He asserts that people can only precognize events that they do not intend to influence, as any attempt to change or alter the future would destroy the resonance that formed the basis of the interaction between the brains of the person’s present and future selves.

Taylor (1995) asserts that this view of precognition is compatible with “free will,” as the person only precognizes those events that he or she does not chose to prevent through an act of intervention.  Taylor hypothesizes that the absence of precognitive feedback, or resonance, between the present self and future events that the subject does intend to influence or prevent provides the basis for nonspecific intuitive experiences that “something is wrong.”   This lack of resonance is subconsciously noticed as a sense of foreboding and thus enables the subject to make decisions based on intuitive feelings.  Taylor postulates that psi phenomena are due to the creation of quantum fields in human brains that are emanated both in space and time.  Psi-mediated information transfer occurs when similar thoughts in one’s present and future selves give rise to a resonance between the quantum field of the present and future brains.  Intuitive psi experiences occur when there is a lack of resonance between the present and future selves (thus implying that some sort of expectancy, such as that one will live through tomorrow’s subway ride, will not be fulfilled).  Taylor predicts that there is no such thing as clairvoyance, in view of the dissimilarity of the quantum fields associated with brains and those associated with objects, and that telepathy and precognition should only be able to occur over limited space-time separations.  Here Taylor may be underestimating the nonlocal nature of quantum fields, as discussed in Chapter 2 and elsewhere in this book.  Also, the existing evidence for information transfer followed by intervention to prevent the precognized event, such as the dream of the falling chandelier discussed above, would seem to constitute strong evidence against Taylor’s theory that intervention can only occur with intuitive experiences.  

The Skeptical Model.  Under this view, there is no such thing as ESP. The mother probably subliminally perceived some dust falling from the unstable chandelier support as she was about to go to bed and then dreamed about the probable consequences.

“Time Flow” and the Psychological Experience of “Becoming.”  The preceding discussion leads us directly into another unsolved fundamental mystery of the universe that ranks right up there with the problem of the relation between conscious experience and material events in terms of its apparent intractability to human analysis.  We seem to find ourselves located at a particular instance in time called the present (or for those philosophers who prefer a thin “slab” of time, the specious present).  The “present” and our consciousnesses seem to be traveling along the time dimension in the direction of the future at a seeming “speed” (to borrow a discredited concept from J. W. Dunne’s multidimensional time model) of one second per second.  Another, perhaps relativistic, way to put it is that time seems to be “flowing” from the future through the present moment and into the past.  Once an event has receded into the past, it is lost to us forever.  To borrow a phrase from Omar Kayyam, “the moving finger writes; and, having writ, moves on: nor all your piety nor wit, shall lure it back to cancel half a line, nor all your tears wash out a word of it.”  We may, if we are lucky, visit the future by being carried there by the “stream of time” but barring the stress of a freefall skydive into a rotating black hole, we cannot revisit the past

Yet modern theories of physics, at least those that incorporate variants of Einstein’s special and general theories of relativity, have no place for a set of events that are uniquely distinguished as the present moment or for the phenomenon of time flow.  In fact, relativity theory does away even with the concept of the “present” as we intuitively understand it; there is no unique set of events (or cross-section of spacetime) that be unambiguously identified as belong to the present or the “now.”  

One of the lesser known paradoxical results of Einstein’s special theory of relativity is that observers in motion relative to one another will disagree on which sets of events (locations in spacetime) should be taken as being simultaneous with one another (i.e. assigned the same time coordinate).  A result of this “relativity of simultaneity” is that two observers in motion relative to each other will disagree on what sets of events (i.e., cross-section of spacetime) should be taken to be the “present.”  It is even possible that two observers will differ as to what they perceive the temporal order of events to be.  In one reference frame, an event X may precede an event Y, whereas in a second reference frame Y is seen to precede X.  In the absence of signals traveling faster than light, such a reversal of time coordinates will be achieved only between events that are “spacelike” connected (i.e., no signal moving at light speed or slower can travel between the two events).  Thus, if events A and B are “timelike separated” and one observer sees A as being the cause of B, a second observer will also perceive that B is later than A and that the causal chain extends from A forward in time to B.  This prohibition against “backward causation” (i.e., an effect preceding its cause in some reference frame) only holds so long as no causal signal may travel faster than light and thus (as we shall see shortly) backward in time in some reference frame.

To illustrate, the relativity of simultaneity, consider Einstein’s famous train example.  Suppose an observer O is at rest with respect to the Earth (let’s give the pre-Copernican motionless flat Earth theory its due, just for the sake of this example).  Further suppose that O is standing at a railroad track and is being passed by the train.  At the moment she is adjacent to the exact center of the train, lightning strikes both ends of the train.  As the speed of light is a constant (and is the same in all reference frames) the light flashes from the two lightning bolts will reach her eyes (or recording equipment) at the same instant.  She will therefore judge them to be simultaneous, as they have both traveled the same distance (half the length of the train) at the same speed (the speed of light is a consequence of the laws of physics and is the same in all reference frames).

Consider however the situation of a second observer O’, who is sitting on top of the train and at the middle of the train.  As the speed of light is finite and as he is moving in the direction of the lightning bolt at the front of the train, the light from that bolt will have to travel a shorter distance to reach him (from the perspective of the observer on the ground), and therefore the light from that bolt will have to travel a shorter distance to reach him than the light from the bolt at the rear of the train.  But, in his reference frame, both bolts have traveled the same distance, namely half the length of the train.  As the speed of light is a constant in his reference frame, he deduces that the bolt at the front of the train must have happened earlier than the bolt at the rear of the train.  Thus, observers O and O’ differ in their judgments regarding the temporal order of the two lightning bolts.

An even more cognitively disturbing example of the relativity of simultaneity involves the case of a woman, possible on a very high dose of steroids and quite likely to win the decathlon in the next Olympics, who is running at nearly the speed of light while carrying a very long javelin toward a barn with a front and back doors.  From the point of view of the farmer standing beside the barn, the pole has shrunk in length due to the Lorentz-Fitzgerald length contraction.  (Another strange consequence of Einstein’s theory of relativity is that stationary observers perceive that the length of objects in motion shrink along the direction of the motion.)  Thus, even though the javelin was longer than the barn just before the woman began her run, because the javelin has shrunk in length (from the farmer’s perspective) due to the woman’s high speed, the farmer is able to open the front door and allow the woman to enter the barn and to close the door behind her.  Thus for a brief time the woman and javelin are contained in the closed off barn.  A very short time after the front door closes, the farmer’s daughter opens the rear door of the barn and is startled to see a very quick woman carrying a javelin come flying out of the barn.

Consider, however, the situation from the standpoint of the Olympian hopeful.  As she is running, in her reference frame the barn is in motion relative to her; thus, its length has shrunk so that it is now much shorter than her javelin.  Not being one to shy away from a collision and possibly owning a spare javelin or two, she continues her rush at the barn and to her amazement is able to pass through it without mishap.  Due to the relativity of simultaneity, she sees her javelin sticking out of both doors of the incredibly shrunken barn at the same time.  In her reference frame, due to the relativity of simultaneity, she sees the farmer’s daughter open the rear door before the farmer closes the front door, so that both doors are open at the same time. 

Because observers in motion with respect to one another will in general disagree about which set of events (spacetime locations) constitute the “present moment,” it is impossible to speak about the absolute existence of a three-dimensional space at a single moment in time (a notion that formed one of the fundamental underpinnings of classical, Newtonian physics).  Different observers will select different “slices” of events as being simultaneous with one another, depending on their state of motion.  Thus, rather than proposing a model involving the existence of a three-dimensional space at a particular time, relativity theorists work with a four-dimensional continuum involving three spatial dimensions and one time dimension.  However, observers in motion relative to one another will not in general agree on the assignments of the spatial and temporal coordinates of events.  If an observer is in motion relative to me, she may see events in my future as having occurred in her past or events in my past as occurring in her future.  Thus in some sense, in relative theory, the future “already exists” and the past “still exists” (in the sense that both the future and the past may be in the present for some observer in motion relative to me but whom I regard as being part of my “now”).

Lawrence LeShan (1969) noted the compatibility of this view of physical reality with such psi phenomena as precognition and “retroactive” psychokinesis (the mental influence of events that have already occurred).  This view is, however, somewhat at odds with the worldview of quantum mechanics, in which the future is not determined and many alterative futures are possible.  Some writers, such as Randall (1998) have argued against theories of the “block universe” type, in which the future is viewed as in some way already existing and thus predetermined, in favor of a model based on quantum indeterminism.  In Randall’s view, models of the latter type are more compatible with philosophies based on “freedom of will.”  (However, one can argue that the “will” may be free to act, but that its actions will be guided by desires and values that are themselves determined.  Thus, the concept of “free will” and a block universe model of reality need not be fundamentally incompatible.)

What modern physics cannot explain, any more than it can at present explain the existence of conscious experience, is the psychological experience of “time flow” and “becoming.”  In fact, the experience of “time flow” may be as fundamental a mystery as the existence of conscious experience itself.  Indeed, as “time flow” is a subjective experience, it quite likely dependent in some unfathomable manner on consciousness.  The two mysteries may thus be somehow intertwined.   

Our experience of time is dynamic and anisotropic.  We are apparently somehow being propelled forward in time.  Alternatively, we experience time flowing past us.  Yet the concept of “time flow” has no place in theories of physics.  As we have just seen, in Einstein’s theory of relativity, all past, present and future events are viewed as a timeless array of points in four-dimensional Minkowski spacetime.   And, as pointed out above, no single cross-section of spacetime can be uniquely defined as the present for all observers.

Neither can theories of physics, for the most part, distinguish the directions of the future from that of the past.  Most physical processes are (theoretically at least) reversible.  An electron and a positron (the antimatter counterpart of the electron) may collide and annihilate one another, producing two photons.  However, it is also possible for two photons to collide, producing an electron-positron pair, and this process appears to be the same as the first process, but reversed in time.

A ball being thrown upward in the air loses velocity due to gravity.  A film of this process, if reversed, would show a falling ball picking up velocity due to gravitational attraction, a process that may occur in the forward direction of time.  The film of a more complicated process, such as a swimmer diving into a pool of water, would appear to represent an impossible sequence of events when run backward (i.e., the swimmer being mysteriously propelled out of the water, instantly drying and landing on the diving board).  Actually, even the reversed film of the dive does not represent an impossible sequence of events, only a very improbable one (it requires a collections of water molecules all to suddenly converge on the swimmer’s body in just the right manner that, through the collective force, the swimmer is propelled vertically out of the water, among other improbable coincidences).  

Similarly, if the door between a hot and a cold room is opened, heat will tend to flow from the warmer room into the cooler room, so that the rooms will become more equal in temperature as time goes on.  The reverse process, wherein one of two equally warms rooms suddenly grows hotter and the other suddenly grows colder (in the absence of any external energy sources) is not impossible, but only very improbable (as it would require most of the faster-moving gas molecules to go randomly into one of the rooms and most of the slower moving gas particles to go into the other, a very unlikely event).  Isolated physical systems will thus tend to evolve from more highly ordered states to more disordered states.  In physics, this is known as the “law” of entropy increase.

While some physical processes, such as the growth of a flower from a seed appear to involve the creation rather than the destruction of order, it should be remembered that terrestrial life forms are not isolated physical systems, but obtain their energy from external sources (e.g., the sun and decomposing organic matter) and thus the law of entropy increase does not apply to them. 

Some philosophers, such as Adolf Grünbaum (1964) have argued that time is inherently anisotropic (behaves differently in the past and future directions) and that the future direction of time may be identified as the direction in which the entropy (disorder) of most “branch systems” (isolated physical systems) increases.  Many other philosophers have been skeptical of this proposal, seeing entropy increase as an artifact of the highly improbable initial state of the universe.  

Closely related to the entropy increase criterion for the direction of “time’s arrow” is the observation that, in general, wavefronts diverge from their source rather than converge upon them.  For instance, a sphere of light may expand from a point light source or a series of concentric ripples may spread out from the point of impact of our irreversible diver into the swimming pool.  Although the differential equations governing the production of such wave allow solutions corresponding to waves converging to a point (i.e., a sink rather than a source), such contracting waves are never seen to occur, perhaps again because of their improbability.  Later in this chapter, we shall see that several parapsychologists have postulated that such converging waves moving backward in time (usually referred to as “advanced waves”) may provide a means of explaining such phenomena as precognition.

The expansion of the universe is also sometimes taken as a criterion for defining the direction of the future.  Given two states of the universe S1 and S2, S1 is taken to be a later state than S2 if and only if the universe is in a more expanded state in S1  than in S2.  However, the expansion of the universe may be an “accidental” consequence of the initial conditions at the time of the Big Bang.  Also, if the universe should proved to be “closed” and to eventually contract back into a “Big Crunch,” then the expansion criterion will prove to be an unreliable arrow in the later phases of the universe’s history.  (As the time of this writing, existing measurements suggest that betters on the Big Crunch should take long odds and that the universe will most likely keep expanding into a “heat death.”  However, given the fact that physicists’ ideas regarding the nature and quantity of dark matter and dark energy in the universe have been changing rapidly in the past five years, this outcome may not be as certain as it now appears to be.)

A fourth possible “arrow of time” is provided by the decay modes of a physical particle named the neutral K meson (K0).  The K0 particle has a decay mode that is curiously irreversible.  The decay modes of most particles are time reversible.   For instance, a neutron may decay into a proton, an electron and a neutrino.  The reverse process, in which a proton, an electron and a neutrino of the right energy converge together to form a neutron, while extremely unlikely, is permitted to occur.  The K0 meson undergoes a decay mode into three particles, which is also time reversible.  However, it is also subject to a very rare two-particle decay mode, and this process is not time reversible.  Thus, it may be possible to use the decay of the K0 meson as a means of defining the future direction of time, although it might produce a sense of uneasiness to use such an anomalous and rare event as the two-particle decay of the K0 meson to define such a fundamental concept as the direction of time.

Another criterion to differentiate the future from the past is the quantum mechanical criterion proposed by Denbigh (1981).  As discussed earlier, in the theory of quantum mechanics, microscopic events (and, through the amplification of their effects, macroscopic events) are not determined prior to an act of measurement or observation.  Thus, the position of a photon is not defined until an attempt to measure it (such as capturing it on a piece of film).

Similarly, in a quantum mechanical random event generator of the type used in modern parapsychological experiments, the random number or other display feature to be generated (which is often based on the time of a radioactive decay) is not determined by the laws of physics and is free to take on any (permissible) value prior to the act of observation.  Thus, the random number to be generated or the position at which the photon will impact the film are indeterminate prior to the act of measurement, and determined thereafter.  The process by which these events are determined is often referred to as “the collapse of the state vector.”  Thus, quantum events, and by implication all events, might be partitioned into two categories - those that have been determined (the observed past) and those that have yet to be observed (which, depending on which interpretation of quantum mechanics one prefers, may include events in the yet-to-be-observed “past,” the present and the future).  This would allow specification of the future and the past relative to any point in time.  However, it does not provide a noncircular definition of the (absolute) present, insofar as what is “now” and “what is yet to be determined” may depend on the observer’s location along the time line.  However, quantum mechanics may provide a physical basis for the sense of “time flow” and “becoming.”  Perhaps the process of becoming is inherently related to or perhaps identical with the collapse of the state vector.  If so, conscious minds may a fundamental role in the generation of “time flow.”   The existence of conscious experience and the subjective experience of time flow, two fundamental mysteries that modern theories of physics have yet to explain, may be intimately related if not identical.  (In this context, it should be noted that the experience of “time flow” and its incompatibility with the essentially deterministic Minkowski spacetime of Einstein’s theory of relativity, may be related to physicists’ current difficulties in relating quantum theory to Einstein’s theory in general and constructing a quantum theory of gravity in particular.)  

According to the “observational theories” in parapsychology, such as those proposed by Schmidt (1975a, 1975b, 1984) and Walker (1975, 1984), as well as some mainstream interpretations of quantum mechanics, quantum events are not determined prior to their observation by a conscious observer.  Thus, a series of random numbers generated by a quantum process is in an indeterminate state prior to inspection.  (This interpretation differs from that of many physicists, who would consider the numbers to be determined at the point where they are irreversibly registered on a macrophysical apparatus such as a punch tape or a computer memory store.)  According to the observational theorists in parapsychology, a sequence of random numbers may be generated, stored in computer memory, and then later displayed to a subject, who may at this later time influence which numbers have been produced through retroactive psychokinesis.  Thus, the generation of these numbers, which would have occurred in the past according to most orthodox accounts of time, would fall into the present (at the time of the PK experiment), if one uses the quantum collapse criterion to distinguish the past from the future. 

Under the observational theories’ interpretation, the quantum mechanical criterion for distinguishing the events that fall into the “future” from those that fall into the “past” might lead to a model of time similar to that implicit in some Native American languages (such as Wintu and Hopi) studied by Lee (1938) and Whorf (1956).  These Indian languages assign tenses to verbs according to whether the events to be described are “manifested” (the outcome is known to the speaker) or “unmanifested” (the outcome is unknown or, in observational theory terms, the event is unobserved, at least from the speaker’s standpoint), rather than according to whether the events are in the past, present or future in the Western (or from Wintu’s and Hopi’s point of view, Eastern) sense of those terms.  Thus, the unmanifested tense might be used to describe the outcome of a battle fought three days ago, if the outcome is unknown because the raiding party has not yet returned to the village.  The observational theory, in its Wintu and Hopi versions, might provide a somewhat solipsistic criterion for demarcating the future from the past, but this division in not likely to result in a clean “slice” of events, as the future would have to include many events that are regarded as belonging to the past based on other criteria.  Nonetheless, the criterion does have the attractive feature of potentially uniting the subjective experience of time flow or “becoming” with the more “objective” (or should one say “subjective?”) notion of the collapse of the quantum mechanical state vector through observation.

The subjective experience of time forms the basis for some theories of precognition.  For instance, Edge (1982) proposes that one’s sense of time becomes “baffled” in sensory deprivation experiments, allowing precognition to occur.  Similarly, Saltmarsh (1934, 1938) suggested that the psychological present is not an instant of time, but encompasses the very recent past as well as the immediate future.  He suggests that this “spread” of the subjective present may involve longer time intervals in unconscious regions of the mind, thus allowing precognition to occur.   

LeShan (1969, 1976) suggests that, in mystical states involving the experience of unity with all things, one may see the past, present and future as one (“all things are now”), much the same as in the Minkowski spacetime of special relativity.  LeShan asserts that this perception of timelessness, in which all things are perceived as one, would be an especially psi-conducive state, and the self-other boundary as well as spacetime separations would no longer exist, at least psychologically.  

As we have seen, the psychological experience of time cannot be explained by orthodox theories of physics.  As best such theories can point a trembling finger in the direction of the future (through the decay of the K0 particle and the widespread existence of waves that diverge from, rather than converge to, point sources).

Thus, the psychological experience of time may be one of the fundamental bedrocks of existence, yet is inexplicable on the basis of current theories of physics.  Some writers have suggested that a profound alteration in the experience of time flow or of spacetime itself may temporarily allow such events as precognition and psychokinesis to occur.  The subjective experiences of the “now” and of “time flow” may point to the mind as a fundamental component of the universe.  The observational theories, with their suggestion that the mind governs the collapse of the quantum mechanical state vector, even hint that the mind may be a primary agent in causing the future (the indeterminate) to become the past (the determinate).  Thus, implicit in the observational theories is the image of the mind as a cosmic “time tractor” plowing indeterminate probability waves into actualized events.  

Perhaps the absolute present may be defined simply (albeit circularly) as that instant in time at which a conscious observer subjectively feels himself or herself to be.

Signal Theories

Several attempts have been made to explain psi phenomena in terms of the exchange of some type of physical signal. Some theories assume that ordinary physical particles carry the psi message. Such particles are typically conceived of as “traveling forward in time.” To explain cases of precognition, some theorists have resorted to more exotic particles that travel backward in time.  We will consider each in turn.

Theories Employing Signals “Traveling Forward in Time”

Particle Theories.   Several theorists have proposed that the transfer of information in cases of ESP is accomplished through the exchange of some signal already known to contemporary physicists, such as electromagnetic radiation and neutrinos.   

Electromagnetic Radiation.  One of the earliest proponents of an “electromagnetic” theory of psi was Joseph Glanvill, a contemporary of Newton, who proposed that telepathic exchanges were caused by the vibrations of the “ether” (see Jaki, 1969).  More modern proponents of electromagnetic theories of psi include Kazhinsky (1962), Becker (1990, 1992), MacLellan (1997), and Vasilescu and Vasilescu (1996, 2001).  Taylor (1975) proposed an electromagnetic explanation of paranormal metal-bending, although he later retracted it (Taylor, 1980).  

Vasilescu and Vasilescu (1996) propose that there exists a “ubiquitous telepathic wave” consisting of electromagnetic radiation with a wavelength of approximately 46.2 meters.  They found ESP effects to be facilitated when they amplified radiation of this wavelength 220 times.  However, an effect was found even when a Faraday cage barrier, which should screen out electromagnetic radiation, was interposed between the sender and percipient.  Some problems with their experiments include the fact that the investigators, who were not blind as to the experimental condition or their hypothesis, served as subjects.  Also, the next trial was signaled by the sender calling our or stamping his foot, which allows for the possibility of sensory cues regarding the target.   

Severe difficulties confront any attempt to explain psi phenomena on the basis of electromagnetic waves.  These difficulties include the apparent ability of psi signals to penetrate barriers normally impervious to electromagnetic radiation, the apparent failure of psi phenomena to obey the usual the usual inverse-square law governing the falloff in electromagnetic effects with distance, the feeble strength of the electromagnetic signals emanating from the brain compared to the power that would be required to send a telepathic signal or perform a psychokinetic feat over any reasonable distance, and the lack of any plausible neurological mechanism whereby such a signal could be encoded, generated, received, and decoded.  Each of these difficulties will be discussed in turn.

 Barrier Experiments.  Successful telepathy experiments have been reported in which the subjects were electromagnetically shielded from one another by Faraday cages and other types of barriers, ruling out the exchange of most electromagnetic signals (e.g., Vasiliev, 1976; Targ & Puthoff,1977; Ullman & Krippner, 1969). Some theorists, including Michael Persinger (1979) and I. M. Kogan (1968), have proposed that psi signals are carried by extremely low frequency electromagnetic radiation, also known as ELF waves.  ELF waves would be able to penetrate some of the electromagnetic barriers used in these experiments.   ELF wave theories are discussed in a separate section below.

Distance Independence.  If ESP and PK effects are due to electromagnetic waves transmitted between the subject and the target person or object, it would be expected that psi success would decrease with increasing distance between the subject and target (as the intensity of electromagnetic information emitted from a point source is inversely proportional to the square of the distance from the point).  The small electrical power of the brain (discussed in the next section) combined with the inverse square law for electromagnetic radiation, would seem to imply that psi effects could not occur over large distances if they are due to electromagnetic radiation.  However, successful remote viewing experiments have been conducted with the percipient (viewer) in Detroit and the agent (sender) in Italy (Schlitz and Gruber, 1980, 1981), and a successful dream telepathy experiment with the agent in Edinburgh and the percipient (dreamer) in London (Markwick & Beloff, 1983).  A series of successful PK experiments, with distances ranging from 10 miles to 1,100 miles separating the PK agent from the target apparatus has been reported by Tedder and his associates (Tedder & Monty, 1981; Tedder & Braud, 1981; Tedder and Bloor, 1982).  Nelson, Dunne, Dobyns and Jahn (1996) and Jahn And Dunne (2005) report that the size of the PK and remote viewing effects obtained by the Princeton Engineering Anomalies Research (PEAR) team were independent of the spacetime separations between the subjects and the target.  Many more examples could be cited.  

The apparent lack of dependence of psi effects on spatial and temporal separations is evidence not only against electromagnetic theories of psi, but against all theories of psi based on known or currently postulated physical signals.  Indeed, the lack of dependence of psi on spacetime separation was one of the factors that led J. B. Rhine, the founder of experimental parapsychology, to proclaim that psi phenomena indicate that the mind has a nonphysical component.  Thus, psi phenomena have long been regarded as evidence against physicalist theories of mind.  As a physicalistic metaphysics underlies current “orthodox” scientific theories, this may explain why the debate over the existence of psi has been so heated and why the evidence for psi phenomena is so strongly rejected by the scientific establishment.  In this regard, one might recall the comments of Anthony Freeman, the Editor of the Journal of Consciousness Studies, who recently noted that “orthodox science is orthodox religion’s true heir” (Freeman, 2005, p. 6).

In a review of literature conducted four decades ago, Osis (1965) did find a slight decline in the strength of ESP effects with distance, although this effect was much weaker than would be expected under the inverse-square law governing electromagnetic radiation and most other types of physical signals.  However, the experiments analyzed by Osis were run under dissimilar circumstances and the subjects were not in general blind as to distance; thus, any distance effect might be attributable to psychological expectancies.

The existence of long-range psi effects and the failure of psi effects to obey an inverse-square law pose grave difficulties for any electromagnetic theory of psi (assuming all psi effects will be subsumed under one theory or mechanism).  So too does the phenomenon of precognition.  If the ultimate explanation of precognition involves signals traveling backward in time (as discussed below), then the normal forward-traveling (‘’retarded”) electromagnetic waves will not suffice (although theories involving “advanced” electromagnetic waves, which travel backward in time, have been constructed).

Power Problems.  The electromagnetic theory of psi was originally inspired by Hans Berger’s detection of electrical currents emanating from the brain through the use of the electroencephalograph (which was invented by Berger), as well as by the invention of the radio.   However, Berger (1940) thought that changes in the electrical potential of the brain were too small to account for telepathy over reasonable distances and so was led to postulate some sort of hitherto undetected “psychical energies” as the carrier of telepathic message.

In fact, several parapsychologists (e.g., Dobbs, 1967; Millar, 1975; Vasiliev, 1976: Bigu, 1979) have performed calculations of the power of the electromagnetic radiated by the human brain.   These estimates have varied widely, from a millionth (Millar) to a quintillionth (Dobbs) of a watt.  However, even electromagnetic radiation at the high end of this range would appear to be far too weak to account for reported ESP or PK effects. 

Encoding and Decoding Problems.  Proponents of electromagnetic theories of psi have proposed no plausible mechanisms whereby such signals could be encoded, generated, transmitted, received, and/or decoded.  Large areas of physical musculature and cerebral cortex are devoted to the production of sound waves to carry messages in speech.  So too, the detection of sound and light waves requires the existence of elaborate external  receptors (the eyes and ears) and the involvement of large areas of the cerebral cortex.  As Vasiliev (1976) points out, the fibers and fluids surrounding the brain possess greater electromagnetic conductivity than do the nerve tissues themselves.  It is implausible that the brain would have evolved in such a manner if it is to serve as a direct and sensitive detector of electromagnetic radiation.  In any event, the analysis of information and pattern detection that would be required in order to receive and decode an electromagnetically-encoded telepathic message would presumably require an organ at least approximating in complexity that of the human eye or ear.  The generation of electromagnetic telepathic signals, besides surpassing the brain’s electrical power capacity, as noted above, would also undoubtedly require the existence of a specialized organ (whose location inside the brain would be most unstrategic).  

ELF Wave Theories.    Thus, insurmountable difficulties seem to confront any attempt to explain psi phenomena on the basis of electromagnetic radiation at typical wavelengths.  Some (but not all) or these objections can be overcome if it assumed that the radiation involved is of extremely long wavelength (or equivalently, extremely low frequency).  Some theorists, most notably Kogan (1968) and Persinger (1979), have hypothesized that psi signals are carried by such extremely low frequency radiation (ELF waves).   Such radiation has a frequency of less than 3 kHz (3000 cycles per second).  Persinger notes that many periodic biological processes occur with frequencies in the ELF range, such as the heart rhythm (less than 4 Hz, or four cycles per second), brain waves (less than 30 Hz), and muscular rhythms (1 Hz to 1 kHz).  He also observes that geological and meteorological processes produce standing waves in the earth-ionosphere cavity with a frequency of 7-8 Hz, which Persinger notes corresponds to the alpha rhythm of the brain, which has been found to be a psi-conducive state (see Honorton, 1977, for instance).  Persinger proposes that “biogenic-environmental interactions” could occur through a “resonance-like” mechanism, in cases in which the frequencies of the geological/meteorological waves and biological cycles are similar.

Persinger essentially proposes two theories of telepathy.  In the first, the agent (i.e., sender of the psi message) would impose an ELF wave on a geophysical system, which would carry the psi message to the recipient.  In the second theory, the brains of the agent and percipient would resonate with an existing physical wave, producing a similar state in both (such as a depressed mood in the percipient and an act of suicide by the agent).  Persinger’s second theory is thus a theory to explain “pseudopsi” events rather than the “real” psi that might occur in an experiment with randomly determined targets.  Stevens (2005) discusses evidence that geomagnetic fields may directly influence the REGs used in psi experiments, which may be responsible for observed correlations between psi success and geomagnetic activity. 

Targ, Puthoff and May (1979) note that one of the attractive features of the ELF wave hypothesis is the slower than inverse-square-law attenuation expected on the basis of earth-ionosphere guide mode trapping as well as source-percipient distances lying within the induction field range as opposed to the radiation filed range.  Not all physicists take such an optimistic view of the ability of ELF waves to carry telepathic messages over long distances.  Walker (1981), for instance, cites successful intercontinental remote viewing experiments as evidence against the ELF wave hypothesis.  

ELF waves are also attractive because of their ability to penetrate electromagnetic shields, such as the Faraday cages used in several successful psi experiments.  Some barriers should prove impervious even to ELF waves, however.  For instance, Targ and Harary (1984) report a successful remote viewing experiment in which the percipient was located in an immersed submarine, which they feel constitutes evidence against the ELF wave hypothesis.  Unfortunately, they do not describe this experiment in full, and their conclusion appears to be based on only two successful trials (with a “hit” probability of 1/6).

Puthoff and Targ (1979) point out that the information channel capacity of ELF waves is very low (they estimate it to be between .005 and .1 bits per second).  As a way out of this difficulty, Persinger (1979) suggests that a subject may be exposed to the signal for a long time before the total message is received, as which point it emerges into the percipient’s consciousness fully formed.  He also suggests that a percipient may learn subtle codings through experience, facilitating ESP communication between family members and friends.  As he acknowledges, the amount of time required for an agent to encode a message (around 100 minutes for 60 bits of information) may be a telling blow against the ELF wave theory.  Persinger concludes that the information transmission rate is too slow for the “real psi” version of the ELF wave theory to be viable (due to short-term memory demands on the percipient), although the “pseudopsi” version may still be tenable.  (Interestingly enough, however, he notes that the ELF wave information rate compares favorably with the information transmission rate in many psi experiments.)

In addition to the above objections, the problems of accounting for the encoding and decoding of any intricate psi message and accounting for precognition confront the ELF wave theory as surely as they do the general electromagnetic theory.

Electrostatic Fields.  According to Lucas and Maresca (1976), the Russian parapsychologists Victor Adamenko and Edward Naumov proposed that certain PK phenomena, such as the attraction and repulsion of small objects by the Russian psychic Nina Kulagina, were caused by electrostatic fields (such as the field that holds a balloon to one’s sweater after the two objects have been rubbed against each other, transferring electrons, which causes the balloon and sweater to have opposite (attracting) charges.  Kulagina’s effects would then be attributable to the normal attraction and repulsion between objects bearing opposite and like electrical charges, respectively.   Indeed, in many of the films of Kulagina’s phenomena, the effects (including for instance her propelling a small cylinder across a table, much as one would push a peanut with one’s nose in a peanut race, but with a slight gap between the finger and the cylinder) do appear that they could be due to such electrostatic attraction and repulsion.  However, Admenko and Naumov also claim that there is an unknown factor that allows such phenomena to occur that cannot be explained on the basis of electrostatic effects alone.

The Neutrino Theory.  Hammond (1952) and Ruderfer (1968, 1974, 1980) have proposed neutrinos as the possible carrier of psi information.  Neutrinos have the desirable feature of traveling at near-light speed (neutrinos are now thought to possess mass, which would prohibit them from actually attaining light speed).  They also have the attractive feature that they can sail right through most barriers such as Faraday cages due to their weak interaction with matter.  Solar neutrinos in fact can and do sail right through the Earth.  However, this virtue is at one and the same time the chief drawback to any neutrino theory of psi.  The vast majority of neutrinos would also happily sail right through one’s brain without interacting with it in any way.  Thus, a person would be unable to receive any psi message sent by neutrinos. Walker (1981) points out that the strength of neutrinos’ interaction with matter is twenty orders of magnitude less than (i.e., ten septillionths as much as) that of electromagnetic radiation.  Because of this weak interaction with matter, in order for an agent to transmit enough neutrinos to ensure that her message was received, her brain would probably have to use up enough energy to power several small cities for months.  Bigu (1979) notes that the human body emits only 8,000 neutrinos per second, which would be far too weak to carry a psi message because of the overwhelming majority of neutrinos will pass right through the human brain without interacting with it in any way. 

Chari (1974) observes that neutrinos could not account for precognition, although elsewhere (Chari, 1977) he notes that Ruderfer has employed tachyons (particles that travel faster than light) for this purpose.  

Also, just as electromagnetic signals, neutrino signals would weaken with distance, as the expanding spherical shells of neutrino radiation emitted would spread out in space and become diluted.  As discussed in connection with the electromagnetic theories of psi, the existing evidence would seem to indicate that psi signals do not weaken appreciably over distance, if at all.  

Furthermore, the problem of explaining the process whereby the psi message is encoded and decoded would seem to be as least as great for the neutrino theory of psi as it is for the electromagnetic theory of psi.  Beloff (1980) has questioned whether any theory of psi based on physical signals can overcome the encoding and decoding problem, given that the same mental state may be given entirely different neurological encodings in two different brains; hence, he concludes that psi must be nonphysical.  However, Beloff’s postulated different neural encodings of the same ideas and emotions in different brains does not prevent humans from communicating these mental contents via language.  It may not be inconceivable that a “neutrino language” could be acquired at a subconscious (or perhaps more aptly, deeply unconscious) level.

Force Field Theories.  Several parapsychologists have constructed explanations of psychokinesis in terms of various types of force fields.  These types of theories are typically invoked for explain psychokinesis rather than extrasensory perception.

Forwald’s Gravitation Theory.  The Swedish engineer Haakon Forwald (1969) explained psychokinetic placement effects on dice (i.e., influencing the direction of the die’s movement rather than which side of the die comes up) on the basis of gravitational forces.  Forwald asserted that gravity has no limited velocity of propagation and thus apparently adhered to the old action-at-a-distance concept of gravitation that so troubled Isaac Newton.  While physicists have yet to construct a satisfactory theory incorporating both quantum mechanics and gravitation, the consensus at present is that gravitational effects are mediated by (yet to be observed) particles called gravitons and even more hypothetical particles called gravitinos and that the speed of these particles (and hence gravitational influence) is limited by the speed of light.  It would in any event be difficult to distinguish superluminal from subliminal signals speeds in a typical dice PK experiment.

Forward proposed an empirically-based mathematical law relating the strength of placement PK effects on the thickness of the metal coating on the dice used in his experiments as well as the number of nucleons (protons and neutrons) in the nuclei of the atoms comprising the coating material, which he takes as evidence of his gravitationally-based model.  Forwald’s theory has not given rise to a sustained research program, and is largely forgotten by today’s parapsychological theorists and experimentalists.

Hasted’s Surface of Action Theory.  The physicist John Hasted proposed a “surface of action” theory to explain the phenomena observed in his own experiments on paranormal metal-bending of the kind popularized by the psychic Uri Geller (Hasted, 1977a, 1977b, 1981, Hasted & Robinson, 1979, 1980).  Hasted based his theory on signals detected in strain gauges placed in metal specimens.  He found that synchronous signals most often occurred when the strain gauges were situated on a line extending radially outward from the subject; however, he presents no statistical analyses to rule out the possibility that these patterns of synchronous signals could have arisen by chance.  Also, Stokes (1982b) has criticized Hasted’s research as lacking significant safeguards against fraud.

Based on signals obtained from a sensor attached to a subject’s forearm, Hasted (1981) concluded that the surface of action is slowly propagated outward from the subject and often consists of a vertical plane containing the axis defined by the subject’s arm.  He estimated the speed of movement of the surface of action to be between 1 cm/sec and 100 cm/sec.  He hypothesized that the surface of action may be curved upon occasion and that obtained twists and spirals in metal specimens are due to the rotation of the surface of action about an axis in its own plane.

Hasted explains the permanent softening of metal specimens by the subject’s acting as a Maxwellian demon (a mythical being capable of sorting high energy from low energy particles and thus producing a violation of the second “law” of thermodynamics, which states that the entropy or “disorder” of an isolated physical system will increase over time).  Hasted hypothesizes that paranormally produced strains in metal specimens are caused by vacancies produced by the teleportation of matter (which he asserted was due to quantum-mechanical tunneling).  Most radically, he hypothesizes that paranormal metal bending is accomplished by the transportation of observers into a parallel universe in which the metal is bent and that the surface of action constitutes the boundary between the two universes.  This is a very unusual interpretation of Hugh Everett’s “many worlds” interpretation of quantum mechanics, in which quantum decisions split the universe into two or more parallel universes, so that each possible outcome of the quantum mechanical process is represented in at least one of the alternate universes.  However, in Everett’s “many worlds” theory, the alternate universes are thought to diverge in a higher-dimensional abstract space called Hilbert space and thus cannot be adjacent in normal three-dimensional space as is assumed in Hasted’s account.  Hasted’s account is also in conflict with the observational theories in parapsychology (to be discussed in more detail later in this chapter).  These theories assert that the observer of the outcome of a quantum mechanical process may elect to enter one of the more desirable alternative futures, not that an observer may be transported from the present universe into an already existing alternative universe.  Elsewhere, Hasted (1979) asserts that teleportation may be explained by assuming that an object may make the transition to an alternative universe at different time than its container, but this is also at variance with Everett’s theory.

The “Moving Beam” Theory.  Based on an analysis of the location, direction, and magnitude of movements of objects relative to a presumed poltergeist agent, Roll, Burdick and Joines (1973) suggest that the movements could have been due to three rotating beams of force emanating from different portions of the agent’s body.  Their “moving beam” theory is a type of force-field theory, although they do not hazard a guess as to the type of force involved or as to how the field is generated.  As arbitrary models can rather easily be constructed to “retrodict” observed patterns of movement, their model needs to be confirmed with new poltergeist agents.  The freedom to adjust the number, size and orientation of the moving beams leads one to suspect that the theory may be untestable (i.e., capable of retrodiction but not prediction) if such freedom is not somehow relinquished.

Quasi-signal Theories.  Many theorists have proposed that some new and hitherto undetected particle or field is the carrier of psi information or is responsible for psychokinetic effects.  The list of such “quasi-signals” in a long one.  The proposed carriers have included psi fields (Wasserman), psychical waves (Berger), psychical fields (Lawden), biogravity (Dubrov), bioplasma (Inyushin and Sergeyev), orgone energy (Reich), and “levity” (a force opposed to gravitation presumed to underlie levitation).  Unfortunately, the proponents of such theories have generally not provided any reliable means of detecting of measuring their hypothetical particles, fields, energies or forces.  They also do not specify the properties of their theoretical entities in a sufficiently exact way that testable predictions might result from their theories.  Thus, not only do they provide no evidence that these previously unknown particles, fields, energies or forces exist, but their theories are unfalsifiable (or, in some cases, highly falsified).

When the proposed medium represents an extension of accepted scientific constructs, very often the extension is inappropriate.  For instance, with respect to Inyushin and Sergeyev’s proposed bioplasma, Wortz et. al. (1979) point out that a classical plasma cannot exist at temperature and pressure conditions consistent with the maintenance of life.  In general, such quasi-signal theories are of no help in explaining psi in that they are often untestable and merely replace one mysterious phenomena (psi) whose existence is debatable with another, even more mysterious phenomenon (the quasi-signal), whose existence is even more debatable.

Resonance Theories.  Some theorists have proposed that psi effects constitute some sort of “resonance” phenomena similar to that which occurs when one tuning fork is struck and transmits sound waves to a second tuning fork of similar construction, which then starts to vibrate also.  (Note that the resonance in this case is mediated by a signal, in this case the sound wave.  Many resonance theories can be construed simply as theories involve signals and/or interacting fields.  What sets resonance theories apart as a special case of signal/field theories is that resonance theorists propose that the psi exchange is facilitated by similarities between the “sending” and “receiving” systems.)  Some theorists have proposed that similar minds (i.e., minds containing shared experiences, thoughts, etc.) may resonate with one another, resulting in the transmission of thoughts, perceptions and emotions from one mind to the other.  

For instance, Marshall (1960) has asserted that there exists an “eidopoic influence” in highly organized material that is capable of rendering faint signals detectable at remote locations by the resonating system, regardless of the spatiotemporal separation involved.   Marshall contends that, through this “eidopoic influence,” similar structures of sufficient complexity, such as human brains, may resonate with one another, thus resulting in a telepathic exchange of information from one mind to another.  Similarly, Hans Berger (1940) postulated that selective telepathic sensitivity to the thoughts of particular people (e.g., close friends and relatives) is due to a form of resonance mediated by “psychical waves.”

In this context, it should be noted that Soal and Bateman (1954) attempted to facilitate telepathy in a card-guessing experiment by providing the percipient (receiver) with a detailed picture of the agent (sender) and the agent’s room.  Such material should increase the similarity of (at least the current) contents of the percipent’s and agent’s mind.  However, this experiment failed to yield any significant evidence of psi.  Rao (1977) contends that pure clairvoyance experiments provide evidence against Berger’s and Marshall’s resonance theories, as it is hard to see such dissimilar structures as an ESP card and a human brain could resonate with one another.  However, one may counter Rao’s argument with the observation that the evidence for pure clairvoyance (direct extrasensory perception of an object) can usually, if not always, be explained away in terms of precognitive telepathy.  

As previously noted, Jon Taylor (1995, 1998, 2000) has also proposed a theory in which psi effects are caused by a resonance between two brains in similar states and denies the existence of pure clairvoyance, attributing the evidence for clairvoyance to trans-temporal telepathy.

As will be discussed in more detail below, Adrian Dobbs (1965) proposed a theory in which precognition is mediated by “psitrons,” hypothetical particles that travel backward in time.  He compared precognitive telepathy to “the resonance or exchange process holding between two hydrogen atoms united by a covalent bond” (p. 311).  Locke (1980) has even been led to construct a resonance theory of psychic healing.  The basic problem with these resonance theories is that they explain one mysterious similarity between two complex systems (psi) in terms of another (resonance).  Unless the signal underlying the resonance (analogous to the sound wave in the case of the tuning fork) and/or the specific types of mental similarities that give rise to resonance can be given a sufficiently exact characterization to yield testable predictions about psi, these theories are unfalsifiable and merely substitute a prejudicial term (“resonance”) for a more noncommittal term (“psi”).  At best, they yield the prediction that psi effects will occur more frequently if there is greater similarity between the minds of the percipient and the agent, a prediction that is yielded by several other theories (such as Whatley Carington’s association theory, which is discussed later in this chapter).

Sheldrake’s Morphic Resonance Theory.  One relatively recent resonance theory for which specific empirical support is claimed is biochemist Rupert Sheldrake’s theory of “morphic resonance” (Sheldrake, 1981, 1983a 1983b, 1988a, 1988b, 1990).  This theory began as an account of the morphological development of the embryo.  In Sheldrake’s view, physio-chemical processes are inadequate to account for the development of the embryo.  He postulates instead that each embryo is associated with a “morphogenetic field” and that similar morphogenetic fields influence each other across space and time through the process of morphic resonance.   Thus, each embryo is able to “tune in” to the morophogenetic fields of similar, previous embryos, which then govern its development.

Sheldrake proposes, for instance, that a bear embryo will be guided in its development through “resonating” with the “morphic fields” of all the bears that have preceded it into the world.  Each creature tends to resonate with similar creatures that have existed in the past.  Susan Blackmore (1985b) has pointed out that Sheldrake’s theory is circular insofar as Sheldrake explains the similarity of two creatures in terms of resonance and the resonance between two creatures on the basis of their similarity.  Similarly, it is difficult to see how morphic resonance could account for the process of evolution and the emergence of novel forms of life, as morphic resonance would confine creatures to repeating previous patterns of biological development.

Sheldrake extends his theory of morphic resonance to account for the phenomenon of memory as well.  After discussing the lack of evidence for physical memory engrams (traces), he postulates that memory may be explained on the basis of morphic resonance with one’s own past brain states.  He hypothesizes that we could survive death with our memories intact, as memories are not stored in the physical brain but are, in his view, the result of morphic resonance.

Sheldrake also proposes explanations of telepathy, reincarnation cases and C. G. Jung’s evidence for a “collective unconscious” in terms of morphic resonance.  He postulates that morphogenetic fields (“motor fields”) may act on a nervous system without violating the limits of fluctuation allowed by the theory of quantum mechanics.  (He similarly proposes that the influence on embryological development remains within the bounds set by quantum theory.)

There is virtually no evidence for the “morphic fields” that Sheldrake hypothesizes govern the phenomenon of morphic resonance, and only a smattering of evidence for the morphic resonance effect itself. 

The initial evidence presented in support of his theory by Sheldrake (1981, 1983b) was scant and consisted primarily of an alleged facilitation of subsequent crystal formation and learning in rats once similar crystals had been formed or rats trained to do a certain task elsewhere in the world.

Much of the remaining evidence derives from a handful of studies that are methodologically flawed in one respect or another.  In one typical study, for example, it was found that a real Japanese nursery rhyme was easier for English-speaking subjects to learn than a newly composed nursery rhyme. Sheldrake (1983a) interpreted this as being due to morphic resonance with the minds of all the Japanese people who had previously learned the nursery rhyme. However, as Susan Blackmore (1985a) pointed out, the rhyme may have been popular in the first place because it was particularly “catchy” and easy to learn. Sheldrake himself acknowledged Blackmore’s point in this regard (Sheldrake, 1983a).  A similar methodological defect occurs in most of the other studies that have been conducted on morphic resonance (see Stokes, 1995, for a more thorough discussion of the methodological flaws in the research purporting to support Sheldrake’s theory). 

Biologists have been quick to condemn Sheldrake’s theory as being baseless and have pointed out that orthodox biological and physical processes can account for most of the biological effects Sheldrake ascribes to morphic resonance.  Not much of a case can be made for nonphysical influences on biological evolution on the basis of the extremely shaky evidence for Sheldrake’s morphic resonance effect.  Blackmore (1985b) points out that Sheldrake does not give an account of how morphogenetic fields arise or what their properties are.  She also points out that Sheldrake does not specify how the similarity between two morphogenetic fields is to be measured.  Certainly, if Sheldrake’s theory is to be testable, he needs to provide some means of measuring parameters relating to morphogenetic fields in order to generate novel predictions; otherwise, his theory adds no explanatory power over and above that of already existing, more orthodox accounts of embryological development in terms of genetic activity, enzymes and molecular gradients.  Also, it would seem that excessive reliance on morphic resonance would hinder the process of species differentiation and adaptation to new environmental niches.

In a recent issue of the Journal of Consciousness Studies devoted to his work, Sheldrake (2005) seems to alter his theory, at least as it would it apply to his experience on the remote detection of staring.  Specifically, he hypothesizes that perceptions and sensations do not take place in the brain or mind but actually out in the material world were they are subjectively experienced.  Thus, when you perceive a red box, the “redness” percept is not in your brain but actually at the physical location of the box.  Sheldrake compares this theory to the extramission theory of vision propounded by the Pythagorean school of philosophers in Ancient Greece.  Under this view, vision was caused by the emission of a signal from the eye to the perceived object, rather than to the passive reception of light by the eye, as thought by adherents to the intromission theory of vision, which would encompass the vast majority of modern neuropsychologists.  Thus, rather than explaining his experiments on the remote detection of staring in terms of “morphic resonance,” Sheldrake instead proposes an explanation in terms of exteriorization of perception space, so that perceptions are actually located externally to the body, just as they subjectively appear to be.  The staree then responds to this alteration in physical space, thus developing “a sense of being stared at.”  Again Sheldrake offers no suggestion as to how such externalized perceptions could be measured.  Also, at least his own experimental evidence for the remote detection of staring is highly flawed.  There are also other accounts of how the effect, if indeed paranormal and not an artifact of sensory cues, is caused, including telepathy as well as the psychokinetic influence of the “staree’s” brain on the part of the “starer.”  Thus, Sheldrake’s hypothesis of externalized perception should be trimmed from the body of scientific theory by Ockham’s Razor (the injunction not to multiply entities beyond necessity in scientific theorizing), as least so long as Sheldrake provides no means of measuring his externalized perceptions at their supposed location in physical space. 

Signals that Travel “Backward in Time”

Retrocausal Signals. Some theorists have proposed that phenomena such as precognition and retroactive psychokinesis, in which the future appears to influence events in the present (or, as in the case of retroactive PK, events in the present appear to influence events in the past), may be explained on the basis of physical signals that travel backward in time.

Philosophical Objections to Backward Causation.  Certain philosophers have maintained that backward causation, in which an effect precedes its cause in time is impossible by virtue of the very meaning of the word “cause.”  Mundle (1964), for instance asserts that it is an analytic truth that a cause cannot succeed its effect in time, arguing that statement “E1 is a cause of E2” entails that event E1 is earlier than event E2 by virtue of the very definition of the word “cause.”  The philosopher C. D. Broad (1967) refutes this objection, noting this the difficulty could be avoided simply by coining a new, temporally neutral word to replace “cause.”  It should be noted, however, that Broad also rejected the notion of backward causation, contending that it was self-evident that a cause could not succeed its effect.  

Despite Broad’s own reluctance to accept the possibility of backward causation, his suggestion points the way to a scientific resolution of the problem.  In may be possible scientifically to discover a set of events C that constitute a sufficient (or necessary) condition for the occurrence of some other event E.  Even though C might contain events later than E, it might be natural under (some subset of) these circumstances to consider C as the cause of E.  Possibly our “forward-looking” habits of though have resulted in our overlooking many such backward causal relationships.  At any rate, the causal relationship has proved to be especially refractory to philosophical analysis over the years, so it may be advantageous to adopt the more logically precise and well-defined notions of sufficient and necessary conditions in place of the more problematic notion of causation.

Incidentally, not all cultures find retrocasual relationships problematic.  Needham (1981) points out that in the view of the ancient Chinese, causation could operate backwards as well as forwards in time, citing an example an explanation of lord’s failure to obtain the hegemony of feudal states on the basis of the fact that human victims were sacrificed to him after his death.  Also, the Hopi and Wintu views of time, as discussed earlier in this chapter, would seem to be compatible with backward causation.  One might easily imagine a chief performing a ritual to influence the course of a battle in the past if the outcome were as yet unknown to him (in which case the events would fall into the unmanifested category based on these Native American languages).

The Evidence for Retrocausal Causal Phenomena.  The two primary parapsychological phenomena that are suggestive of “backward causation” are precognition and retroactive psychokinesis.  Explanations of precognition in terms of “forward causation” (such as dreaming about an event and then causing it to occur via psychokinesis) were discussed in the previous chapter.

One issue not addressed in the discussion on separating types of psi in Chapter 4 is the evidence for retroactive psychokinesis, in which subjects attempt to influence random events that occurred in the past according to conventional notions of time.  

Helmut Schmidt, the designer of the quantum-mechanically used random event generators that are widely used in parapsychological work today, postulated that a psi source (typically a conscious observer) may influence the outcome of a quantum-mechanically based process (such as the output of a Schmidt-type REG) and that this influence is independent of the spatiotemporal separation between the subject and the target events (Schmidt 1975a, 1975b, 1984).  Even if the target events are generated and recorded on a punch tape prior to the subject’s attempt to influence them, the subject is postulated to be able to influence the earlier behavior of the REG at the time the target events are presented to the subject (e.g., as flashing lights on a Schmidt four-button machine).   The possibility of such retroactive PK has led Schmidt to call PK (and psi in general) “noncausal” or “acasual.”  Schmidt (1979) is of the view that, if an effect precedes its ostensible cause, the relationship between the two events cannot be causal, apparently accepting the semantic arguments that a cause must precede its effect by definition.

Braude (1979), Beloff (1980) and Nash (1983) have objected to the notion of retroactive PK (as least as formulated by the “observational theorists” such as Schmidt) on the basis of circular causation.  Braude asserts that the PK effort is only assumed to be effective after the subject has been given the feedback (as the influence of the quantum process is brought about by the act of observation).  A similar contention is made by Zohar (1982).  Thus, in Braude’s view, the presentation of the correct target is required in order to cause the PK effect, which then causes the correct target to be generated, thereby creating a causal loop.  Braude objects to casual loops as he denies that an event can be the cause of itself; however, Gödel’s demonstration of the existence of closed time solutions to Einstein’s equations suggests that causal loops may be possible in a consistent universe, as illustrated in the previous story regarding the space traveler who was his own father/mother, son/daughter grandfather/grandmother, grandson/granddaughter (…, i.e., his whole family tree).

Contra Braude’s interpretation, the observational theories (such as Schmidt’s theory) require only that feedback as to the outcome of the target process be given to the subject as some point in time in order for the psychokinetic effect to occur.  One could therefore conceptualize the process as follows.  The subject, aware of the reinforcement contingency that if the REG’s output is a “1” he will get a shock and if it is a “0” he will get a jolt in the pleasure center of his brain, forces the REG to output a “0” at a point in time earlier than the actual feedback.  One could visualize this as a linear causal chain beginning with awareness of the reinforcement contingency, followed by the influence of the REG, and then ending with the jolt to the pleasure center, thus avoiding any casual loop.

Statistically significant evidence for retroactive PK has been reported by many investigators, including Schmidt (1976, 1981), Terry and Schmidt (1978), Gruber (1980), and Schmidt, Morris and Rudolf (1986).  However, while the objections based on casual loops can be answered to a large extent, most or all of the actual experimental evidence for retroactive PK can be explained away in terms of “forward causation.”  In this regard, retroactive PK may enjoy an even murkier status than precognition.  For instance, an experimenter who wants to run a retroactive PK experiment, in which the subject will attempt to influence a previously recorded target sequence to obtain more “0s” than “1s” may simply exert a direct psychokinetic influence on the REG at the time the targets are generated.  In some cases, as in precognition experiments, such counterexplanations in term of forward casual chains can become quite convoluted and thus implausible.  

Advanced Waves. We will now turn to a consideration of explanations of such phenomena as precognition and retroactive PK in terms of signals that travel “backward in time.”

One such signal is what is known as “advanced waves.” The differential equation that governs the motion of electromagnetic and sound waves is time-symmetric and admits of two solutions. The first corresponds to the normal “retarded” wave, which propagates outward from a source and travels forward in time. The second is a mirror image of the first and consists of an “advanced” wave, which travels backward in time.  Such a wave might be experienced by an observer “traveling forward in time” as a contracting shell of light that converges on a light bulb at the instant it is turned on.

Advanced electromagnetic (and sound) waves suffer from all the same inadequacies of normal “retarded” electromagnetic waves when it comes to explaining psi.  The brain simply does not possess enough power to send a signal via advanced waves over any substantial distance in space and time. Another disadvantage of advanced waves is that, although they are theoretically possible, they have never been observed to exist.

Walker (1981) has pointed out that advanced electromagnetic waves must satisfy the same laws of propagation as retarded waves, including the inverse square law (that states that strength of signal will vary inversely with the square of the distance from the source).  Walker notes that an advanced electromagnetic wave would have to circumnavigate the earth in order to transmit a precognitive signal a mere 0.13 seconds into the past.  Bigu (1979) points out that it would take an acoustical wave 16 hours to traverse the semiperimeter of the Earth, which is still a much shorter time interval than that claimed in many cases of precognition.  He also notes that higher sound frequencies undergo rapid attenuation.  Bigu concludes that advanced waves are not likely to play a role in precognition unless “anomalous” regions of space (wormholes perhaps?) induce substantial time delays.  

Gerald Feinberg (1975), a physicist who developed the theory of tachyons (particles that travel faster than light), has pointed out that, if advanced waves occurred frequently, double images should appear in many astronomical observations (although the prominent physicists John Archibald Wheeler and Richard Feynman have argued that such advanced waves will always be cancelled out by their reflections in a matter-dense universe).  Also, all the objections to the real-time electromagnetic theory of psi based on difficulties in accounting for the encoding, generation and decoding of signals would seem to apply to the advanced wave theory of psi (as well as to the other theories that attempt to explain psi on the basis of retrocausal signals to be discussed below).

It is apparent that considerable difficulties confront any attempt to explain precognition on the basis of “external” advanced waves.  Feinberg (1975) proposed a rather novel advanced wave theory, based on the notion that the advanced wave is confined within the brain of the person having the precognitive experience.  In Feinberg’s model, when one experiences or learns about an event, “an oscillatory variation of some internal patterns in the brain occurs” (p. 59).  This oscillatory variation may have both retarded and advanced components.  Feinberg suggests that the retarded component may correspond to short-term memory, whereas the advanced component corresponds to precognition.  Thus, Feinberg suggests, precognition may correspond to a “memory” of a future state of the brain.  In this regard, Feinberg’s theory is similar to Jon Taylor’s theory that precognition is due to resonance between the quantum fields of the subject’s present and future brain states (Taylor, 1995, 1998, 2000) as discussed earlier in this chapter.

Feinberg asserts that, if the retarded oscillatory pattern corresponds to short-term memory, then the advanced-wave based precognitive ability should have only a short temporal range similar to that of short-term memory.  Also, there should be a decay in precognitive ability as the time interval between the experience and the confirming event increases.  Feinberg hypothesizes that long-term precognition might be made possible through “chaining” if one person tells another of his precognitive experience, the second precognizes that feedback and tells a third person of the “meta-precognition” and so on.  This would not seem to be a typical occurrence in most actual instances of apparent precognition.

Feinberg could possibly have accounted for long-term precognition in terms of the rehearsal strategies that are often effective in keeping items in short-term memory (such as repeating a telephone number over and over again).  Feinberg predicts no correlation between precognition and spatial distance, as he hypothesizes that subjects only precognize events within their own brain (e.g., a precognition of a plane crash may not be direct, but rather a precognition of one’s brain state as one reads an account of the crash in the newspaper the next afternoon).  Feinberg predicts a positive correlation between precognitive ability and short-term memory and predicts that techniques used to bolster short-term memory will also be helpful in precognition.  He proposes that there is no precognitive equivalent of long-term memory, as this is likely to involve structural changes in the brain rather than a continuing oscillatory pattern.

Feinberg’s theory, and the other theories of precognition based on retrocasual signals to be discussed below predicts that precognitive attrition (in which precognitive experiences are more frequent and more detailed over shorter time intervals) should occur.  The evidence for precognition attrition is discussed later in this chapter.  Feinberg’s theory also predicts that a subject must have future sensory awareness of an event in order to precognize it.  However, several studies have reported evidence of precognition without feedback.  For instance, in an experiment specifically designed to test this hypothesis, Bierman (1977) found evidence of precognition without feedback, although he conceded that his results could be due to experimenter psi (thus saving Feinberg’s theory, as experimenters typically do receive feedback).

An advanced wave theory of retroactive PK has been proposed by de Beauregard (1979).  De Beauregard hypothesizes that observers may collapse quantum mechanical wave functions (i.e. select a particular outcome of a quantum mechanical process) retroactively through the emission of such advanced waves.  It is, however, somewhat difficult to see how an advanced wave can collapse a state vector, when retarded electromagnetic waves are not usually regarded as having this capability.  Like Walker (2000), De Beauregard suggests that there may be rudimentary psyches or “monads” determining all quantum events.  De Beauregard also climbs out on the precarious intelligent design limb of the scientific tree by postulating that “finalistic advanced waves,” are responsible for biological phylogenesis and ontogenesis, thus proposing that the development of biological species and individual organisms is guided by some sort of vitalistic end state in the future (i.e., perhaps engineered by “monads” located “downstream” in the river of time from us).

Antimatter. Another possible retrocausal signal is antimatter. Antimatter, despite its provocative name, is not an esoteric form of matter out of science fiction but is an ordinary form of matter that is observed daily in particle accelerators around the world. Every particle of matter has its corresponding antiparticle. The antiparticle of the electron is called the positron; it has the same mass as the electron but carries a positive electrical charge, whereas the electron is negatively charged. When an electron meets a positron, they annihilate one another. Their mass is converted to pure energy in the form of photons.  If a substantial quantity of matter were to meet up with a corresponding amount of antimatter, a powerful explosion would occur. (This is the source of power for the propulsion drive of the spaceship Enterprise in the popular Star Trek series).

The Nobel winning physicist and legendary character Richard Feynman noted that antimatter could be regarded mathematically as ordinary matter traveling backward in time. Thus, a positron could be conceived of as an electron traveling into the past.  Consider a case in which a high-energy photon creates a positron-electron pair at spacetime location A.  Assume the positron then meets up with a second electron and annihilates with it at spacetime location B, producing a second photon.  (Please note that due to the law of conservation of momentum, such a process is forbidden in empty space, but may occur in the presence of matter, as pointed out by Leggett, 1987b). Under Feynman’s interpretation, this process could be regarded as the trajectory of one electron. The electron would be regarded as traveling forward in time to event B, reversing its direction through the emission of a photon, traveling backward in time to event A, where it reverses its direction once more through the emission of a photon traveling backward in time (photons are their own antiparticles) and returns to its normal forward trajectory in time. This would be analogous to the more usual case in which an electron zigzags back and forth in space, emitting and absorbing photons to change direction.  In fact, as Feynman related in his Nobel prize acceptance speech, the physicist John Wheeler once suggested to him that the reason why all electrons have the same mass is that they are all the same particle, zigzagging backward and forward in time (Wheeler was only joking).

What would antimatter-based time travel look like to us if we were to encounter an instance of it while walking down the street?  We might notice a big burst of light in front of the drug store.  Out of the explosion, two seemingly identical men would emerge, one walking forward and one walking backward. If we were to examine the one walking backward under a microscope, we would see that he was getting seconds younger with each step and that his beard was retreating into his skin. Suddenly, we see a third copy of the man across the street. The man walking backward crosses the street, miraculously avoiding all the oncoming traffic even though his head is turned away from it. He then seems to back into the third copy of the man that is walking on the other side of the street. There is a giant explosion, after which both men have disappeared. (Actually, most towns would have been destroyed in this process, but we will assume that this one was particularly well constructed.)  What really happened? This man has the ability to reverse his direction in time by emitting photons and changing himself into antimatter. As he was walking down the street, he thought he heard someone in front of the drug store across the street make disparaging remarks about his toupee.  Just to make sure, he reversed direction in time and walked over to hear what was really said.  After crossing the street, he again reversed his direction in time in order to eavesdrop more effectively. (It is much easier to interpret sound waves when one is going forward in time.) 

At least one parapsychologist has attempted an explanation of precognition and retroactive PK in terms of such Feynman-like zigzagging of particles back and forth through time.  De Beauregard (2002) uses such time-reversed motion to argue against the postulation of extra dimensions of spacetime by such theorists as Rauscher and Targ to account for psi, as discussed earlier in this chapter.  

In trying to account for precognition on the basis of antimatter signals, one runs into all the usual problems of signals weakening with distance (and time) and the difficulties of trying to account for how the brain could generate and decode such a signal, especially in view of the scarcity of antimatter in our region of the universe.  With antimatter, there is the additional problem that any message sent by antimatter particles would quickly degrade as the antimatter would rapidly annihilate with matter, which constitutes the predominant form of material particles, at least in our region of the universe.

The final problem is that antimatter need not be regarded as matter traveling backward in time. This interpretation is really based on a cheap mathematical trick on Feynman’s part. It is perfectly legitimate to regard a positron as a positively charged particle traveling forward in time rather than a negatively charged particle traveling backward in time.

Tachyons. Some parapsychologists, including Martin Ruderfer (1974) and Adrian Dobbs (1965, 1967), have proposed that tachyons carry the psi signal in cases of precognition.  Tachyons are particles that travel faster than light and therefore have the ability to go backward in time, as will be explained below. Dobbs’ theory is in fact quite elaborate and essentially involves the emission of tachyons from one of the alternative futures in a branching time model.

The existence of tachyons has been postulated by such physicists as E.C.G. Sudershan and Gerald Feinberg.  (Feinberg, it will be remembered, has proposed his own version of an “advanced wave” theory of precognition.) Tachyons always go faster than the speed of light.  Paradoxically, the less energy a tachyon has, the slower it goes.  However, you would have to apply an infinite amount of energy to slow a tachyon down to the speed of light.  Tachyons’ ability to travel backward in time depends on the relativity of simultaneity.  As explained in more detail earlier in this chapter, In Einstein’s theory of relativity, two events that are perceived as simultaneous by one observer may not be perceived as simultaneous by another observer.

Here is how communication into the past via tachyons might be achieved. Suppose that a man has been sent to jail because he has been caught in an embezzling scheme. Over the course of few months, he is able to construct a crude tachyon transmission device out of soap flakes, pipe cleaners and discarded razor blades. He uses the device to send a signal to his friend Jimmy “the Weasel” Peterson, as the Weasel hurtles through space away from the authorities in his souped-up getaway ship. The transmission instructs the Weasel to send a message to the prisoner’s girlfriend, Susan Wayward, telling her to remove a crucial piece of evidence from his apartment and to plant it in the apartment of his despised rival at the accounting firm where he used to work. Due to the relativity of simultaneity, because the Weasel is moving rapidly away from the prisoner, portions of the prisoner’s past lie in the Weasel’s future.  Thus, the Weasel is able to use a tachyon signal to get the message to Susan a full month before our protagonist is caught and convicted of embezzlement. Consequently, he was never sent to jail in the first place and is now a free man.

This of course brings up the subject of changing the past. It seems logically contradictory that the prisoner could both have been sent to jail and not sent to jail. These sorts of causal paradoxes are one of the reasons why many philosophers and scientists regard time travel as being inherently impossible.  It would, however, be possible to avoid the paradoxes by adopting a branching time model.  Once Susan has received the Weasel’s signal, a new time branch has been created, one in which the embezzler will not be sent to prison.  This does not help the prisoner, however, as the version of the embezzler that should be most important to the prisoner is still sitting in jail on the first time branch.  All he has succeeded in doing is freeing many of his twins in Everett’s parallel universes. (Although his message in fact created these alternate universes, no mean feat in itself!)

The ability of tachyons to travel backward in time appears to be based on the assumption that judgments regarding simultaneity will continue to be based on light signals. Because light is the fastest known signal, it is used to define simultaneity in the special theory of relativity. If an observer takes a snapshot of an event, the event photographed is defined to occur at a time halfway between the time of the emission of light by the camera’s flashbulb and the time of the reception of the light back at the camera’s lens (as the light travels equal distances in both directions and is assumed to travel at a constant speed).  Yet if tachyons exist, light would no longer enjoy its privileged status as the fastest available signal, and simultaneity might have to be defined in terms of tachyon signals instead. In fact, if infinitely fast signals were available, the relativity of simultaneity might disappear altogether. Of course, such a redefinition of simultaneity might have unforeseen repercussions on the laws of physics (affecting the assumption of the constancy of the speed of light in all reference frames, for instance).  Nevertheless, if an absolute simultaneity could be established using tachyonic signals, tachyons might be deprived of their retrocausal properties, as has been pointed out independently by physicists John Bell (1986) and Basil Hiley (1986) and by the writer (Stokes, 1985).  

Another major drawback to the tachyon theory of psi is that tachyons have never been observed to exist; they remain purely theoretical constructs.  In the 1970s, physicists Roger Clay and Philip Crouch (1974) claimed to have detected evidence for tachyons in the form of anomalous particle events that preceded the main showers of particles caused by cosmic rays; however, later experimenters were unable to repeat this observation.

Tachyon theories suffer from all the usual difficulties confronting signal theories of psi, including the fact that tachyon signals would be assumed to rapidly weaken over distance (and time).  There is also the problem of accounting for how the brain could encode, generate and receive a tachyon-based psi message. This problem is even worse in the case of tachyons than it is for the other signal theories, as there is no good theory of how tachyons could interact with the tardyons of which human observers are composed (tardyons are particles that travel slower than the speed of light).  In fact, physicist Nick Herbert (1988) has outlined several mathematical obstacles confronting any attempt to construct a theory of tachyon-tardyon interaction.

Precognitive Attrition. In all the retrocausal signal theories we have discussed, the signals involved would be expected to spread out and weaken as they travel backward in time. Thus, one would expect a “precognitive attrition” effect to occur, whereby precognition would be more effective over short time intervals than over long time intervals.

Many case investigators claim to have detected a decline in the number of precognition cases with increasing time intervals between the precognitive experience and the confirming event.  In his analysis of Louisa Rhine’s collection, Sybo Schouten (1982) found 33 percent of the precognitive experiences to involve intervals of less than 24 hours, 67 percent to involve intervals shorter than two weeks, and 95 percent to involve intervals less than one year.  Schouten found no significant relation between the form of the experience and time interval, although he notes that virtually all cases involving intervals greater than one year were dreams.  

Schouten (1991), in a review of the history of parapsychology in the Netherlands, notes that both J. M. J. Kooy and J. C. M. Kruisanga kept diaries of precognitive dreams and that Kruisanga’s data showed a pronounced decline effect with time, although the exact nature of this decline effect is not made clear in Schouten’s paper.

Other investigators (e.g., Green, 1960; Orme, 1974) have also found evidence for a precognitive attrition effect in analyzing collections of reported spontaneous experiences.  Orme based his conclusion on an analysis of several published collections of spontaneous cases.  He found a nearly linear relationship between the logarithm of case frequency and the logarithm of the associated time interval.  He compares precognition to memory, citing Ebbinghaus’ finding of a logarithmic relationship between memory retention and time.  

De Pablos (1998) reported finding a precognitive attrition effect in 23 of his own ostensibly precognition dreams as selected from a dream diary containing 223 dreams.  Specifically, he found the time interval between the dream and the confirming event to be less than 24 hours in 61% of the cases, to fall between one day and two weeks in 22% of the cases, with the remaining 17% of the cases involving a time interval between two weeks and 2.5 months.

In a later publication involving a study of 124 of his own dreams, de Pablos (2004) reported a “log-log” (i.e., power law) relationship between the frequency of occurrence of precognitive dreams and the time interval between the dream and the confirming event.  

De Pablos proposes a model in which precognition is viewed as akin to the process of memory, but operating in a time-reversed fashion, similar to the theory proposed by Feinberg as discussed above, but involving long-term rather than short-term memory.  The storage of memory traces normally involves the encoding of the to-be-remembered event, followed by consolidation of the memory trace or engram, followed eventually by the retrieval of the memory.  De Pablos proposes that, in precognition, the retrieval of the “memory” of the future event comes first, followed by time-reversed “consolidation” and then by the encoding of the event at the future time at which it occurs.  De Pablos notes that the effect of precognitive attrition is compatible both with a signal transmission model of precognition and with the “precognitive forgetting model” he proposes.  He notes that the signal transmission model suggests that precognitive experiences should occur in roughly the same temporal order as the confirming events, whereas his precognitive forgetting model is more compatible with a “topographic” ordering of events, presumably by meaning and emotional significance.  As memory consolidation takes time (sometimes on the order of years for full consolidation), de Pablos predicts that short-term precognition should be less consolidated than long-term precognition, and that therefore precognitive experiences involving longer time intervals would be expected to be more detailed than those involving shorter time intervals.  De Pablos asserts that under the theories explaining psi in terms of retrocausal signals one would expect that there would be a loss of information over longer time intervals.  His ratings of his own dreams indicated that there was more information in ostensibly precognitive dreams involving longer time intervals, whereas those involving short time intervals were more apt to be analogical or symbolic rather containing a lot of correct realistic detail.  

Based on his “future memory” theory of precognitive dreaming, de Pablos predicts that acetylcholine, a neurotransmitter shown to enhance memory, would also facilitate precognitive dreaming.  He also suggests testing acetylcholine inhibitors to determine if they suppress precognitive dreaming.

It should be noted that frequently reported findings that the strength of psi effects is independent of space-time separation, such as those of Jahn and Dunne (2005) provide some evidence against the precognitive attrition hypothesis, although these experimental findings typically do not involve precognitive dreams, but are more often focused on spatial separations in ESP experiments and spacetime separations in PK experiments.

These findings of a precognitive attrition effect in spontaneous case collections might be explained on the basis of selective reporting of cases.  Cases involving relatively short time intervals may seem more impressive if the confirming event occurred one day after the dream than if it occurred fifteen years later.  Also, only striking correspondences may be noticed between an event and a dream that occurred a long time ago, whereas trivial correspondences might be noticed between an event and a dream that one had last night.  Also, if a long time interval is involved, it may take more details to make the experience seem sufficiently “non-coincidental” to report.  This might explain de Pablo’s finding that number of details in his precognitive dreams increased with the length of the time interval between the dream and the confirming event.   Also, people may forget precognitive dreams over long time intervals and be unable to recall them at the time of the confirming event.  For all these reasons, one might expect a decline in the number of reported cases as the time interval between the experience and the confirming event increases, even in the absence of any real precognitive attrition effect.

Nancy Sondow (1984, 1988) reports a decline in the number of her own precognitive dreams with increasing time interval.  Her analysis is based on a diary of her own dreams, which contained 943 entries. She argues against the hypothesis that the decline effect is due to increased forgetting of dreams over longer time intervals, noting that when she “overlearned” the dreams through repetitive study there was no reduction in the slope of the decline. There remains, however, the possibility that the decline effect could be an artifact of dismissing a dream from consideration after encountering an apparently confirming event, thus preventing the matching of the dreams with later events. For instance, precognition of one’s grandmother’s funeral one week from now might be interpreted as precognition of her death two days hence, reducing the “real” interval of one week to an apparent interval of two days.  

Restricting their analysis to “coincidence” cases (in which the experience and the confirming event were separated by less than 24 hours in time), Rinaldi and Piccinini (1982) found 5.2 percent of the cases to fall within the interval of 12-24 hours before the event, 10.8 percent within 6-12 hours before the event, 16.3 percent within 1-6 hours before the event, 62.7 percent to occur within an hour of the event, 1.9 percent to fall within 1-6 hours after the event, 1.9 percent within 6-12 hours after the event, and 1.2 percent to fall within 12-24 hours after the event. This may constitute evidence for precognitive attrition that is not so easily explainable by the above counterhypothesis of forgetting and dismissal after premature matching.  Rinaldi and Piccinini attribute the clustering of cases within an hour of the event to a possible “improvement” of testimony.  However, as will be seen below, Charles Tart (1983) found higher scoring rates in ESP experiments employing real-time rather than precognitive targets, which would be consonant with Rinaldi and Piccinini’s findings.  Rinaldi and Piccinini (1982) also report an analysis of forgetting artifacts in spontaneous case collections. They note that the number of cases reported declines as the amount of time that has elapsed since the experience increases. They found 168 cases per year for intervals of less than 6 months between the experience and interview, 47 cases per year for intervals from 6 months to 2 years, 33 cases per year for intervals from 2 to 5 years, and 27 cases per year for intervals from 6 to 10 years.  Dream and intuition cases appeared to be forgotten at a faster rate than were the possibly more striking hallucination and physical effect cases.  Cases involving death were not forgotten so quickly as cases not involving death.  This forgetting factor may possibly bias the composition of spontaneous case collections to some degree.  In any event, if already confirmed cases can be forgotten over time, it stands to reason that as-yet-unconfirmed dreams and hunches might well be forgotten if a long time interval separates them from the confirming event.

Turning to experimental evidence, Charles Tart (1983) found no evidence of a correlation between time interval and rate of psi information transmission in an analysis of published precognition experiments employing forced-choice ESP targets.  He does note that the rate of information transmission was higher in “real-time” ESP experiments than in precognition experiments (his analysis being restricted to experiments obtaining significant evidence of psi). Tart suggests that real-time ESP and precognition may represent different abilities, although he concedes that the difference in scoring rates could be due to psychological barriers to the acceptance of precognition that would undermine the subject’s performance. He does not address the issue of whether methodological flaws in some real-time experiments (such as the existence of sensory cues allowing the subject to identify the targets) may be responsible for the high hit rates in some of the real-time ESP experiments.

On the other hand, in a later meta-analysis of forced choice precognition experiments published during the years 1935–1987, Honorton and Ferrari (1989) found significant evidence of a decline in the size of the obtained psi effect with increasing time intervals.  This decline seemed to be due to studies with average citizens as subjects; studies using subjects preselected for their psi abilities actually showed a positive relationship between effect size and time interval. Honorton and Ferrari suggest that these effects may be due to differences in motivational factors between the two types of subjects.  The experimental evidence for precognitive attrition is thus somewhat equivocal.

A second means of testing the hypothesis of precognitive attrition is to determine whether the overall accuracy and number of details in the precognitive experience declines over time.  Schriever (1987) found no difference in the time intervals involved in highly accurate and less accurate dreams in her analysis of the dream diary of an actress.  Sondow (1988) found no significant decrement in the accuracy or number of details in her own precognitive dreams over increasing time intervals.  She suggests a possible psychological explanation for her evidence for precognitive attrition (discussed above), namely that people may largely restrict their precognitive monitoring to the near future.  Haight (1979) likewise found no relationships between temporal interval and completeness of information, conviction, or importance of the confirming event in her study of experiences reported by high school students.  In this context, it should be remembered that, in a study of his own dreams and reported in a “dream diary,” de Pablos (2004) found that more information was contained in precognitive dreams involving long time intervals than in dreams involving short time intervals, which he took to support his theory that precognition corresponds to “memories of the future” that become more consolidated as they propagate “backward in time.”

Even if the number of details in precognition cases were to decline as the time interval increased, such a decline could be explained on the basis of forgetting.  For instance, Schouten (1981) found that the number of details reported in experiences in the Sannwald case collection fell off as the amount of time that had elapsed before reporting the case increased.  The length of the report also declined.  Schouten attributes these effects to forgetting.  These effects are also evidence against the critics’ charge that such cases will be improved or embellished over time; the evidence suggests instead that the cases deteriorate as details are forgotten.

In summary, the evidence for precognitive attrition is equivocal. It is possible to argue that many reported declines in frequency of cases over increasing time intervals may be due to forgetting as well as the premature matching of experiences to events. The experimental evidence, as reviewed by Tart (1983) and Honorton and Ferrari (1989), is also equivocal.  There is no compelling evidence for a weakening of psi signals, in the form of a decrease in the number or accuracy of the details in an experience, over increasing time intervals.  (Of course, to the extent that people will be more reluctant to report less detailed cases, it might be possible that a reduction in the number of details would be reflected indirectly in a decline in the number of cases reported over increasing time intervals rather than directly in the composition of the reported cases themselves.) 

In any event, as the evidence for precognitive attrition is so equivocal, it is impossible to come to a firm decision about the viability of theories ascribing precognition to retrocausal signals on the basis of precognitive attrition.

The Observational Theories

The “signal” theories of psi that have been just discussed are all based on the assumption that some relatively localized particle or wave carries the psi message.  As we have seen, these theories all have rather severe drawbacks.  However, as discussed in Chapter 2, experiments in the quantum mechanical realm indicate that the universe does not consist exclusively of discrete, mutually isolated and localized particles and objects.  In fact, the theory of quantum mechanics paints a picture of the universe that is not at all hostile to psi phenomena.  Indeed the principle of nonlocality in quantum mechanics would almost lead one to anticipate the existence of psi.  If not even two protons separated by light years can be conceptualized as separate objects, perhaps it is also incorrect to consider persons as encapsulated, spatially isolated entities. Seeming separate persons may in fact merely be different facets of a higher nonlocal entity.  The mysterious connections between apparently isolated elementary particles in field of quantum mechanics make the prospect of psi interactions between people much more palatable.

As noted in Chapter 2, science has generally proceeded by the analysis and dissection of complex systems into their component parts, the ultimate parts being of course elementary particles such as electrons and quarks.  In the orthodox scientific view, higher-order and holistic mental phenomena, such thoughts and beliefs, will ultimately be explained in terms of the activity of “lower order” entities such as neurons and synapses, whose activity is in turn explained by still lower entities such as molecules and quarks.  At least this is the view according to the “orthodox,” Newtonian view of the world that is still (consciously or unconsciously) clung to by most mainstream scientists, despite the fact that quantum mechanical evidence indicates that such a view is outmoded and incorrect in fundamental ways.  This type of explanation is known as “upward causation.”  The philosophy upon which it is based is called “reductionism,” as it assumes that the properties of complex systems, such as people, can be reduced to the properties of their components (such as atoms). Several parapsychologists have called for an abandonment of the exclusive reliance on upward causation in science, basing their arguments in part on quantum nonlocality.  In his Presidential Address to the Parapsychological Association, Dean Radin (1989) proposed quite strongly that instances of “downward causation” also occur and are neglected by orthodox science.  Such downward causation might consist of an influence of the mind on the behavior of molecules, for instance. 

Stephen Braude (1986) has also criticized the “small-is-beautiful” bias of reductionistic science, and William Roll (1987) even recommends extending the traditional biological hierarchy beyond atoms, cells, organs and organisms to encompass a superorganismic level of description.  

In a Presidential Address to the Parapsychological Association, K. Ramakrishna Rao (1978) noted the similarity the principle of nonlocality in quantum mechanics, in which all events are, at least potentially, interconnected and the Vedantic doctrine of the identity between atman (or a person’s individual consciousness) and Brahman (the Supreme Self or World Mind).  Rao suggests that the practice of yoga may facilitate the occurrence of psi phenomena, as it enables the self to sink back into a primordial condition of unity with the rest of reality. 

Several parapsychological theorists (e.g., Roll, 1982b; Villars, 1983; Nash 1983, 1984a; Giroldini,1986; and Shan, 2002), have explicitly proposed that psi phenomena may due to nonlocal quantum connections between the elementary particles in someone’s brain and particles in another person or object.  Shan, for instance, hypothesizes that telepathy may be mediated by quantum entanglement between brains and suggest that psi might be facilitating by inputting entangled photons into the subjects’ eyes.

This hypothesis that psi effects are due to quantum entanglement at the particle level runs into difficulties on several fronts. First, it is difficult to believe that pairs of particles could be maintained in a coherent quantum state while residing in separate physical objects, including brains, for any reasonable amount of time.  Second, this hypothesis assumes an ability of a person or brain to track the past history of particles that is far more miraculous than the psi powers it is invoked to explain.  Third, no psi message can be sent through such nonlocal connections under standard interpretations of quantum mechanics, as the behavior of both particles in a pair is apparently random at each site (although they are correlated with each other).  The only way a psi message could be sent or a PK influence exerted would be for the mind to force the quantum process to occur in a preferred manner (such as by sending a message in Morse code by making protons spin up or down with respect to a selected spatial axis).  This would implicitly equate the mind with the so-called “hidden variables” that determine the outcome of quantum processes.  As these variables must necessarily be nonlocal, why not simply assume that the mind exerts its influence on the object directly rather than through particles in the brain that happen to be correlated with particles in the target?  The latter view seems to be mired in a view of the mind as a localized entity, despite its explicit appeal to quantum nonlocality.

Several theorists, including Helmut Schmidt (1975a, 1975b, 1984), Harris Walker (1975, 1984, 2000, 2003) and Richard Mattuck (1977, 1982, 1984), have in fact taken the position that the mind should be equated with the hidden variables of quantum mechanics and that the mind should be seen as capable of directly influencing the outcome of quantum events.  Their theories are collectively known as the “observational theories.”  This term derives from the fact that, as discussed in Chapter 2, attributes of quantum particles, such as the position of an electron, only take on definite values when an act of observation is made to determine what those values are. 

If being observed by a conscious mind somehow causes the electron’s position to assume a definite value, the observational theorists reason, perhaps the conscious mind can also somehow determine what particular position the electron will adopt.  As discussed in the previous chapter, parapsychologists have amassed a large body of evidence suggesting that the mind may be able to influence the outcomes of quantum processes in the form of significant PK influences on quantum mechanically based random event generators.  So the observational theories are not without experimental support.  Specific mathematical versions of the observational theory have been proposed by Schmidt, Mattuck and Walker; however, these models have not given rise to any sustained research programs.  Thus, the mathematical models proposed by these writers have not been confirmed by a large (or even medium-sized) body of evidence directed specifically at testing the specific predictions of these models . Any reader interested in the technicalities of these models may find a discussion of them in some of my previous publications (e.g., Stokes, 1987, 1991) as well as in the primary sources cited above.

The Divergence Problem. One problem faced by the observational theories is that due to the assumed spacetime independence of psi, later observers may be in a position to influence the outcome of a quantum process that has “already” been observed by earlier observers.  For instance, if a PK experiment in which a subject attempts to influence the output of a quantum mechanically-based REG is published in a scientific journal, then the readers of the journal are secondary observers of the output of the REG (if only in summary form).  The number of later observers is potentially large and may include persons reading accounts of the research in newspaper or viewers of television shows on paranormal research.  Such persons may thus be in a position to influence the research via retroactive PK.   Schmidt (1974a) was in fact the first to point out this problem, noting that the effects of a large number of later observers would be sufficient to cancel out or overwhelm the psi effects of the designated primary observers in the experiment.  In fact, Schmidt (1978) noted that the original formulation of his model predicts that, given a large number of secondary observers, the hit rate will be 50%, no matter what the chance probability of a hit is. Houtkooper (1977) derived from Schmidt’s model that, under a different set of assumptios than those used by Schmidt, the hit rate for a large number of observers should be 0 or 1, meaning that the experiment should yield either all hits or all misses.  As these rates are not observed in actual PK experiments with quantum mechanically based REGs, either Schmidt’s theory, or else Schmidt and Houtkooper’s assumptions, must be false.  As the predictions derived by Schmidt and Houtkooper are a result in part of the assumption of the spacetime independence of psi, one way out of this difficulty would be to abandon the assumption of spacetime independence.  

Schmidt (1974a) proposed one means of circumventing the divergence problem, which was to assume that the psi process continues for a finite amount of time and then is somehow “’turned off’ so that PK influences by later observers vanish” (Schmidt, 1974a, p. 215).  Millar (1978) proposed the simple remedy of assuming that only the first observer of a quantum process has any effect.   Hartwell (1977) proposed a mathematical modification of Schmidt’s model in which the influence of later observers was decreased.  Schmidt also proposed an emended version of his model in which the probability that a quantum process remains uncollapsed exponentially decays with time, with the decay rate a function of the observers’ “alertness.”

Stanford’s Conformance Behavior Theory

 Stanford (1978) has proposed a theoretical model that is closely related to the observational theories.  He calls his theory the “conformance behavior” model of psi.  Stanford challenges the “psychobiological” or “cybernetic” model of psi, which assumes that psi abilities are similar to other sensory-motor functions.  For instance, Stanford maintains that under the cybernetic model, PK is understood as analogous to other motor skills in that it assumes that the application of the PK force is guided by ESP feedback about the current velocity and position of the target object (such as a rolling die).  Stanford cites evidence that psi success is independent of task complexity as evidence against the “cybernetic model.”  For instance, one would not expect as much success in a blind PK task (in which the subject must first learn the identity of the target through ESP and then psychokinetically influence the die to correspond to the target) as one would expect in a straightforward PK test in which the target is known to the subject.  However, the experimental data so not show a marked decline in results when the blind PK paradigm is implemented.  Studies have also shown no decrease in PK success when the PK target is a complex, multi-process REG as opposed to a simple single-process REG.  As evidence of the complexity-independence of ESP, Stanford cites an experiment by Foster (1940) showing no deterioration in performance when a subject had to integrate information from two extrasensorially perceived cards from that when the information was contained on a single card.  It should be noted that the task-complexity independence of psi is also predicted by other observational theorists, such as Schmidt, who postulates that the size of the psi effect is dependent only on the probabilities of the final output of the REG and the strength of the subject as a psi source.

 Stanford interprets all psi events as the conformance behavior of random event generators (including human brains as well as the quantum-mechanical REGs used in psi experiments) to the needs of a “disposed system” (which is typically the subject or experimenter in a psi experiment or one of the people involved in a spontaneous psi incident).  In order for conformance behavior to occur, the REG must produce events that are “unequally attractive” to the disposed system.  Furthermore, “labile” or “noisy” systems (characterized by a great deal of random fluctuation) should produce more conformance behavior than more deterministic systems.

 Several authors have provided critiques of the conformance behavior theory.  Rao (1977) has criticized the theory as being much like the observational theories, but without their predictive value.  Indeed, Stanford’s theory does not lead to the precise quantitative predictions characteristic of other observational theories such as those of Schmidt, Walker, and Mattuck (although, as ready noted, the predictions of these latter theories remain to be verified).  

 Beloff (1979a) has noted that it is not clear what constitutes a “disposed system” in Stanford’s theory.  Indeed, Stanford explicitly raises the question of whether conformance behavior might be found in cases involving nonorganic disposed systems, leading one to wonder whether computers and coiled springs might have psi abilities under Stanford’s theory.  Beloff goes on to argue for the psychobiological paradigm, noting that there is no evidence for psi in the absence of living systems. 

LeShan’s Alternate Realities

Leshan’s concept of “alternate realities” (LeShan, 1969, 1976, 1984; LeShan & Margenau, 1982) provides a transition point between the observational theories and nonlocal theories employing the notion of a collective mind.  In LeShan’s view (which he developed in concert with his friend, the noted physicist Henry Margenau), there may be many equally valid ways of construing or looking at reality.  Different models of reality may be needed to interpret different domains of experience.  Furthermore, the concepts of one model may not be reducible to (i.e., explained in terms of) the concepts of another; rather the concepts of one model often “transcend” those of another.  

Although two such models (which LeShan calls individual realties, or IRs) may appear to contradict one another, LeShan states that the principle of complementarity may be invoked to justify the employment of these seemingly contradictory world views within their own domains of explanation, much as Neils Bohr originally invoked the principle of complementarity to justify the alternate use of the seemingly contradictory wave and particle models of light (as light seems to behave as wave in some experimental contexts and as a particle in others).  Thus, each model is equally valid within its own domain.

LeShan has proposed a variety of possible individual realities, but his original distinction between the “clairvoyant” or mystical IR and the “sensory” IR (LeShan, 1969) remains the most germane to the explanation of psi phenomena.  LeShan states that each IR is characterized by its “basic limiting principles,” a term he adopted from the writings of the philosopher C. D. Broad (1962).  (Broad’s own “basic limiting principles” were essentially restatements of the impossibility of psi phenomena.  Broad asserted that these principles underlie the worldview of most modern scientists.)

In the sensory IR, which corresponds to the ordinary, waking state of consciousness, the world is seen as comprised of separate and discrete objects, information can be gained only through sensory input, time is divided into past present and future, and flows irreversibly “from the future, into the now, and into the past” and “free will” exists insofar as decisions made in the present can alter the future.

In the clairvoyant, or mystical reality, which is supposedly a way of looking at the world attained in mystical states, objects are not seen as separate or discrete from one another (“all things are one”), information about an object may be acquired directly due to the identity of self and object (hence allowing psi), time is without divisions into past, present and future (“all things are now”) and free will does not exist (as “all that will be is,” and thus the future, already existing, cannot be changed).

LeShan sees the clairvoyant IR as a psi-conducive state, and he equates it with the view of reality contained in modern theories of physics.  While it is true that the special theory of relativity abolishes an absolute distinction between past, present and future), and both relativity theory and quantum mechanics stress the dependence of observed phenomena on the state of the observer (“self and object are one”), it is equally true that the indeterminism inherent in quantum mechanics is often taken as support for the doctrine of free will.  Thus, while some concepts such as the principle of nonlocality in quantum mechanics and the relativity of simultaneity would seem to be compatible with LeShan’s clairvoyant IR, quantum indeterminacy would not.  (In fact, as discussed previously, quantum indeterminacy might comprise a “backdoor” by which the concept of an absolute “now” might sneak back into physical theory.)  Also, the relativity of simultaneity cannot be invoked to explain precognition.  For instance while those events in my future “light cone” (the set of events I can influence via causal signals traveling at or below the speed of light) may be in the present for an observer moving rapidly relative to me, the limiting velocity of the speed of light prohibits any causal signal from reaching me from my future light cone.  Furthermore, the events in my future light cone will be defined as being in my future no matter what reference frame is invoked.  Thus, an absolute future remains for any observer despite the relativity of simultaneity. 

It is also not clear that LeShan’s theory is capable of generating any exact empirical predictions other than (possibly) the space-time independence of psi and the psi-conducive nature of mystical states (which is already predicted by psychological theories).

In a revision of his theory, LeShan (1984) drew a distinction between the “realm of sensory experience” and the “realm of consciousness” (although he maintains the distinction between the sensory IR and the clairvoyant IR as well).  In the realm of consciousness or mental experience, space has no meaning and it is equally meaningless to talk about separate objects; thus, telepathy is permissible in this realm.  He asserts that psychological phenomena are unquantifiable; however, this contention seems dubious in view of modern research in the areas of experimental and mathematical psychology.  Such research includes Shepard’s (1978) demonstration of the analogy between the rotation of mental objects and the rotation of physical objects through reaction time studies and Sternberg’s (1969) discovery of nonterminating memory searches, also through reaction time studies. 

LeShan states that no possibility of prediction exists in the realm of consciousness as the same situation cannot be repeated twice; hence, there can be no law of causation, whether “absolute” or “statistical.”  Thus, free will exists (unlike in the case of LeShan’s “clairvoyant IR”).  Somewhat inconsistently, LeShan considers that the (mental) past can be shown (through retrodictive psychoanalytic techniques, etc.) to have been determined, but still contends that the future is not (although when it becomes the past, it can be retrodictively shown to have been determined all along!).  LeShan (1984) explicitly notes the analogy between altered states of consciousness and his IRs and asserts that altered states of consciousness typically accompany the adoption of alternate models of reality, suggesting a connection between LeShan’s ideas and Tart’s concept of state-specific sciences as discussed above (Tart, 1972).

It should be noted that many other authors have drawn connections between the emerging world view of modern physics with mystical and transpersonal states of consciousness, including Capra (1975) and Zukav (1979) among many others.  More recently, the PEAR team of Jahn and Dunne have proposed models of consciousness and psi phenomena couched in terms of the same technical concepts used in quantum physics (Jahn & Dunne, 1987, 2001, 2004; Jahn, 2002).  However, the quantum formalisms offered by Jahn and Dunne appear to be merely analogies, and it is doubtful that testable predictions can be deduced from these models.

The Collective Mind

If individual persons cannot be thought of as separate and autonomous from one another, perhaps it would make sense to abandon the assumption that their minds are entirely separate from one another and to raise the possibility that individual psyches may be aspects of a group mind or collective unconscious. In fact, several parapsychological thinkers have postulated the existence of a collective mind in order to explain telepathy and other forms of psi phenomena. Some of these theorists, such as G. N. M. Tyrrell (1953) and C. G. Jung (1973), have postulated that individual minds may share common regions at a deep level of the unconscious. Steinkamp (2002) has noted that the existence of psi phenomena imply that our “selves” are not entirely separate from one another and that precognition suggests that one’s own present and future selves may not be separate.  William Roll (1988, 1989) has suggested that the Iroquois’ concept of the “long body” (a kind of collective mind encompassing one’s family and other intimate acquaintances) might usefully be employed in attempting to understand psi phenomena. We will consider several of these theories in turn, beginning with that of Jung.   

Jung’s Theory of Synchronicity and the Collective Unconscious. Carl G. Jung was one of Freud’s most prominent disciples in the early psychoanalytic movement; indeed, he was regarded as Freud’s “crown prince” until he broke with Freud to found his own school of Analytical Psychology.  To account for similarities in the hallucinations and delusions of his psychotic patients (as well as the presence of apparent references to classical mythology in the delusional productions of apparently uneducated schizophrenic patients), Jung was led to postulate the existence of a “collective unconscious.”  Jung proposed that this collective unconscious existed at a deeper level of the psyche than the “personal unconscious” discovered by Freud.  He also invoked the collective unconscious to explain the many similarities among the mythological and religious traditions of apparently unrelated peoples.  Not only was the collective unconscious conceived to be basis for the common primordial images (archetypes) that appear in various mythological traditions, it was also conceived of as containing “racial” or “inherited” memories of the entire history of humankind. (Freud had also propounded the doctrine of inherited memory in his own theorizing.)

Some of Jung’s followers have invoked the work of such ethologists as Konrad Lorenz and Niko Tinbergen on “innate releasing mechanisms” (indicating that, for instance, a bird of a given species has an apparently genetically-based tendency to sit only on eggs of a certain type) as evidence for the existence of inherited memory images or at least of primordial or archetypal imagery.  While the inheritance of this sort of tendency to respond to a particular “sign stimulus” is not in dispute, the doctrine of the inheritance of specific memories has fallen into general scientific disrepute along with the rest of the Lamarckian doctrine of the inheritance of acquired characteristics. (Lamarck thought, for instance, that giraffes’ necks might have become longer through generations of being stretched in order to reach leaves on tall trees, whereas the modern neo–Darwinian theory holds that giraffes that inherited random mutations that made their necks longer were able to outcompete their rivals for food.)

Jung also proposed the existence of an “acausal connecting principle,” which he called the principle of “synchronicity.”  This principle acts to produce “meaningful coincidences.” An example of a synchronistic occurrence is provided by the case of one of my friends in graduate school, who, not being prepared for the preliminary examination for his doctoral degree, postponed the examination after much soul-searching.  That night, he went to eat in a Chinese restaurant. When he opened his fortune cookie, it said, “It is best to put off until tomorrow that which you may botch today.”

Jung viewed the collective unconscious as being capable of extending its influence to the external physical world.  In fact, he regarded all reality as being “psychoid” in nature (meaning that even seemingly inanimate objects have a psychic component).  For instance, in one oft-discussed incident, Jung was in the middle of having an argument with Freud when loud raps were heard, seemingly coming from a nearby bookshelf.  Jung attributed this coincidence to the “exteriorization” of an archetype (a doctrine that he also invoked to explain sightings of ghosts).

Several parapsychologists have objected to Jung’s use of the term “acausal” to describe synchronistic occurrences. First of all, many of Jung’s examples of synchronistic effects could be explained on the basis of ESP or PK. For instance, Jung might have unconsciously used his own psychokinetic powers to produce the raps in the bookcase (he described feeling intense symptoms of anger in his abdomen just preceding the incident).  Also, it seems that Jung implicitly assumed that synchronistic events are in some sense caused by factors in the collective unconscious.  As Beloff (1978) has noted, Jung seems to confuse causation with mechanical causation.  What Jung probably wanted to deny was the existence of ordinary physical causes for synchronistic effects.  Beloff (1974) has also argued that it is difficult to explain the movement of large objects in poltergeist cases as being due to a “meaningful coincidence” as the events are virtually impossible in the first place.   However, it should be noted that Jung himself and the German parapsychologist Hans Bender (1980) have invoked Jung’s notion of reality as psychoid and his concept of the collective unconscious to account for certain types of poltergeist and other macroscopic PK effects.

It would, however, seem as though these explanations are causal rather than acasual in nature.  Although no direct causal chain may link, say, the anger in a poltergeist agent and the inexplicable movement of a filing cabinet in Jung and Bender’s interpretation, both events seem to be postulated to be caused by psychic events happening somewhere in the collective unconscious (hence the theory really is in fact a casual theory, despite Jung’s protestations).  Palmer (2004) notes that Jung’s theory in fact is a casual theory, with the archetypes of the collective unconscious acting as causal agents.  As both Beloff and Palmer point out, the confusion over the causation issue is linked to Jung’s equation of causation with mechanical “billiard ball” causation.  To the extent that Jung abandons causation altogether, he is throwing out the baby with the bathwater and rendering his theory unfalsifiable, as it may be difficult to derive empirical predictions unless it is assumed that one set of circumstances will give rise to (cause?) another set of circumstance.

It was, incidentally, Jung’s abandonment of the principle of mechanical causation that made his theory so attractive to Arthur Koestler, who saw similarities between Jung's principle of synchronicity and the mysterious interconnections between apparently mutually isolated physical events involved in quantum nonlocality, as well as Mach’s principle and the Pauli exclusion principle in physics (Koestler, 1978).  As Palmer (2004) notes, in Koestler’s view the principle of synchronicity encompassed “meaningful coincidences” between two physical events, whereas Palmer interprets Jung as restricting the principle to pairs of events in which at least one of the events is psychically “inner” or subjective.  

Tyrrell’s Theory of Subliminal Selves. The parapsychologist G. N. M. Tyrrell (1953) proposed a theory of the collective unconscious that bears a certain resemblance to Jung’s theory.  

According to Tyrrell, the human personality consists of a hierarchy of selves.  Essentially, Tyrrell believed that people share regions of their minds at a deep unconscious level.  He asserted that, at the unconscious level, the “midlevel centers [of the personality] possess in some degree both the qualities of selfhood and of otherness from self” (p. 119, italics in original).  It is in these regions that our dreams and hallucinations are constructed, which is why witnesses are consistent in their descriptions of collectively perceived apparitions.  Also, as this deep region of the unconscious has no organization in space or time according to Tyrrell, it enables telepathic exchanges to take place.

James’ “Cosmic Consciousness.” William James, one of the pioneers of both American psychology and American psychical research, postulated the existence of a “cosmic consciousness” into which individual minds merge during mystical experiences. James (1909/1960) saw the everyday, normal state of consciousness as being a circumscribed form of awareness designed for adaptation to the “external earthly environment.”  James’ vision of a cosmic consciousness corresponds closely to Rao’s depiction of an implicate order bearing a resemblance to the World Mind or Brahman of Hinduism.

Myers’ Metetherial World.  F. W. H. Myers (1903), one of the discoverers of the unconscious mind and a leader in the early psychical research movement, also postulated the existence of a deep region of the unconscious or “subliminal self” capable of accounting for paranormal events (although he was somewhat vague as to the mechanism underlying psi).   He also proposed the existence of a “metetherial world,” which he conceived to be a world of images lying beyond the normal world of ether (the substance once thought to be the medium in which light waves propagated, but which is now generally regarded as nonexistent by physicists).  On the basis of the fact that apparitions are frequently seen by more than one observer, Myers was led to conjecture that apparitions are not mere hallucinations but have a real existence in the metetherial world. He called such apparitions “metetherial presences” and conjectured that they represented modifications in regions of physical space, thus implying some sort of coextension between normal physical space and the metetherial world. Myers compared the metetherial world to a dream world, noting that phantoms often appear to behave in a dreamlike manner. Thus, Myers’ metetherial world might be considered to be a form of collective unconscious. 

Myers’ view that apparitions occupied regions of physical space and were external to the minds of the percipients of the apparition was opposed by his contemporary Edmund Gurney (e.g., Gurney, Myers & Podmore, 1886a, 1886b), who believed that collectively perceived apparitions could be accounted for on the basis of the telepathic spreading of a hallucination from one percipient to the others.  Writing nearly a century later, Osis (1981) proposed that different theories may be required to explain different types of hallucinations (such as collectively vs. individually perceived apparitions).

Price’s Dream World. The philosopher H. H. Price (1939, 1940, 1948, 1953, 1959, 1961) also argued for the existence of a collective unconscious, noting that the possible existence of continuous telepathic rapport between minds makes it foolish to argue for a total separation of minds.  Like the philosopher Henri Bergson (1914), he assumed that a repressive mechanism acts to prevent biologically irrelevant telepathic information from entering consciousness while the person is awake.  He suggested that this suppressive mechanism may be relaxed in the dream state and in the states of dissociation associated with mediumship, making these states particularly conducive to the occurrence of psi phenomena.

Price proposed that one survives death in a dreamlike afterlife, whose characteristics are determined in part by a person’s wishes and beliefs (and in part by telepathic impulses from other minds).  Price assumed, like Myers, that the images persisting in the psychic “ether” may acquire a life of their own and may be responsible for experiences of hauntings and apparitions.  In particular, Price argued that cases in which persons undergoing out-of-body experiences have been perceived at the locations to which they have projected (that is, “reciprocal hallucinations”) provide evidence that apparitions serve as “vehicles of consciousness.”  Noyes (1998) has also proposed that an afterlife realm such as Price’s world of images could be in some sense coextensive with, and have effects in, the physical world, producing phenomena such as apparitions and materializations.

In an extension of Price’s theory, Michael Grosso (1979) suggests that the ego may become fragmented in the afterlife and that, when one’s wishes and desires are played out, one may eventually achieve the sort of transpersonal state experienced by mystics.  Grosso attributes the repetitive, rudimentary forms of behavior frequently exhibited by ghostly apparitions to such fragmentation of the personality. 

More recently, Patterson (1995) also proposed a form of afterlife equivalent to a collective dream.  Patterson notes that such a world would be an intersubjective, but not purely objective, realm.   Of course our current dreams depend on the activity of a neural substrate (our brains), and it is not clear that dreams of an discarnate soul lacking such a substrate could be qualitatively similar to the dreams of a human with an intact brain.

Carington’s Association Theory.  The noted psychical researcher Whately Carington (1949) proposed a variety of “neutral monism” in which the universe is considered to consist exclusively of “cognita,” atomistic mental events related by the laws of association.  If an agent (i.e. sender in a telepathy experiment) happens to be thinking of cognitum A at the same time that he is exposed to cognitum B (the target), an associative link will be established between A and B.  Thus, when a percipient thinks of A, this will tend to call up the association B, and he will become aware of the agent’s experience.  The more cognita or K-ideas (connecting ideas) that are shared between the agent and percipient, the higher the likelihood of the telepathic transfer of information between the two will be, which explains the frequency of telepathy between closely related persons (who presumably share many cognita and associations).

At least one attempt to test Carington’s theory by providing the percipient with a detailed picture of the agent and the agent’s room (in an attempt to increase the number of K-ideas linking the two) failed to produce any evidence of psi (Soal & Bateman, 1954).  However, the notion of using K-ideas to bolster psi is not dead by any means.  Although they do not mention K-ideas or Carington by name, Murray, Simmonds and Fox (2005) have presented a new research design in which both sender and receiver will be immersed in similar virtual realities in an attempt to facilitate telepathy.

Carington’s theory has the distinctively negative feature of abandoning the assumption of the existence of the physical world without replacing the powerful predictive value of physical theories with any comparable predictive value of its own.  A further difficulty with Carington’s theory is its assumption of a single value for the associative strength between two cognita A and B.  Surely, the strength of the association between A and B will vary from mind to mind, as a large amount of empirical evidence will attest. 

Murphy’s Theory of the Interpersonal Field.  The well-known American psychologist (and parapsychologist) Gardner Murphy proposed a theory of the collective mind type, in which every psychological event is hypothesized to leave a trace in the “interpersonal field” or “paranormal matrix” (Murphy, 1945).   Murphy further contended that the normal concepts of space and time do not apply to the paranormal matrix, thus allowing psi.  

Rao (1966) has challenged Murphy’s explanation of psi phenomena in terms of the paranormal matrix, observing that the evidence for pure clairvoyance is difficult to account for on the basis of this theory, unless one postulates the existence of a psychic aspect to all objects.  Rao also asks if the interpersonal field contains traces of all psychological events, past, present and future.  If not, the paranormal matrix theory may be unable to account for precognition.  If so, Rao asks, is it not a contradiction to talk about events “leaving a trace?”

Murphy (1973) proposed that the mind might survive death in a fragmentary state in a type of collective consciousness.  However, Murphy noted that the idea that the individual mind will survive death in an intact condition presupposes that the individual mind is a rigid, encapsulated entity.  Instead, Murphy argued, the individual mind, being merely an aspect of a larger field of consciousness, may take on new qualities and form new structural relationships, no longer clinging to its narrow, biologically-oriented form of organization.  He quotes Nietzsche’s remark that the ego is a “grammatical illusion,” and notes that the Buddhists deny the existence of a personal soul.  William Roll (1982a, 1984) has cited instances involving the apparent fusion of memories from different people in mediumistic communications and in past-life memories reported by children as giving further support to Murphy’s contention that personalities may undergo fragmentation, fusion and reorganization after death.  

Murphy’s views of the collective mind and possible afterlives are similar to those proposed by Price, Grosso and Carington.  To further wed his theory to Carington’s theory, Murphy suggests that the localization of apparitions in haunting cases may be due to K-ideas provided by the physical location.

Hardy’s “SeCo Theory.” Hardy (1998) proposed a theory that is similar to that of Carrington and Murphy, in which the mind is seen as composed of interacting and somewhat autonomous “semantic constellations” (or “SeCos” in her terminology).   

Palmer’s “Psiad”  Theory.  Palmer (1995) proposed that patterns of brain activity can give rise to integrate packet of psychic content called “psiads.”  Once formed, the psiads can exert psychokinetic effects on the brains that gave birth to them.  The psiads may drift free of the “mother brain” and exert psychokinetic effects on other host brains with activity or mental content similar to that occurring in the “mother brain” at the time of the psiad’s development.  Meanwhile, the original mother brain is giving birth to new psiads.  This provides a mechanism to explain telepathy.  Palmer asserts that telepathy should be most common between individuals who are genetically related.  However, a great many spontaneous cases on record involve telepathy between spouses.  Perhaps, a lifetime of common experiences provide an additional basis for psiads to “glom onto” a new host brain.  Palmer attributes collectively perceived apparitions and similar experience to psiads simultaneously interacting with multiple percipients’ brains.  He also explains mediumship and cases in which children report memories related to previous lives (as discussed more fully in Chapter 6) to interactions with psiads.  Gauld (1996) has noted that psiads would not provide a mechanism for personal survival, but only for the survival of a fragment of one’s experiences that would bear a tenuous relationship with the original self or person.  Gauld further notes that it is different to see how an experimental test could distinguish between Palmer’s theory and, say, the association theories proposed by Carington and Murphy.

Roll’s Theory of “Psi Fields” and the “Long Body.”   Another version of the collective mind theory has been proposed by William Roll (1961, 1964, 1966, 1979, 1981, 1982a, 1982b, 1983).  Roll contends that physical objects contain “psi fields,” or localized memory traces of events happening in their vicinity.   This quasi-physical memory trace may then interact with the memory system or psi field of an observer, such as in the form of ESP known as psychometry or object reading, in which a psychic uses physical contact with an object to facilitate extrasensory contact with a person or place associated with the object.

Roll has suggested that normal memory may consist of nothing more than psychometry of the brain.  He further postulates that the system of psi fields constitutes a type of collective mind he calls a “psi structure.” He suggests that individual minds are not entirely separate entities but a merely parts of this psi structure.  Even mind and matter may not constitute separate domains in Roll’s theory.  He asserts that people remain psi-contiguous with people and places with whom they have interacted in the past, and he compares such “psi-contiguity to quantum entanglement.  He predicts little or no success in an ESP task unless the subject has been in close physical proximity to the target, due to a lack of psi contiguity in such a case.  Roll asserts that a person may “survive” in the form of the traces he or she leaves in the psi fields of objects.

He explains place-related effects, such as hauntings in which a ghost is seen performing some repetitive act in a particular location in a house, as being due to the activation of the psi fields associated with a particular location or object.  He notes that apparitions, like memory traces, dissipate over time, thus the form of survival of death Roll is postulating is a time-limited one.  

Roll incidentally, denies the existence of backward causation.  In the case of an ostensibly precognitive dream, Roll suggests that either an event in the “psi structure” is responsible for causing both the dream and the confirming event or that the dreamer leaves a “charge” in the psi structure, which later causes the confirming event.  Thus, under Roll’s theory, psi fields are capable of influencing or causing physical events and thus may account for PK as well as ESP.   

In recent years, Roll (1988, 1989, 2005) has reformulated his theory in terms of the Iroquois’ concept of the “long body.”   The long body encompasses one’s tribe, its physical environment and other material objects associated with the self or tribe.  As Williams (2005) points out, the idea of the long body bears a similarity to the beliefs of many the southwestern United States tribes as well, including the Hopi, Navajo, Laguna and Zuni.  Williams also notes that the concept of the long body was first introduced to parapsychology by Aanstoos (1986) before it was adopted and extended by Roll.  Under the concept of the long body, close friends and relatives as well as tribal objects and lands are considered part of the self.  Thus, the concept of the long body supports the existence of psi phenomena. 

Summary of Collective Mind Theories.  Obviously, if telepathy exists, human minds can no longer be thought of as entirely separate objects and one person’s mind may be thought of as part of the unconscious mind of another person.  Thus, the existence of some sort of collective mind is trivially true if psi exists.  The similarities among the various versions of the collective mind theory are obvious, and it would be difficult in most instances to find ways of testing between them.  The extent to which psi is to be attributed to a collective unconscious or to interactions between separate minds may to a large extent be a matter of emphasis, although some empirical evidence, such as collectively perceived apparitions, would seem to favor the collective mind theory over the separate minds theory.  As argued both at the outset of this book and in later chapters, it is doubtful that the self, conceived as a center of pure consciousness could be identified with the memory systems, associational links and Jungian archetypes postulated to inhabit the collective mind.

The “Shin” Theory

The parapsychologists Robert Thouless and B. P. Wiesner proposed an “internal psi” model of mind-brain interaction (Thouless & Wiesner, 1948).  In referring to the mind, they use the Hebrew letter “Shin” (ש) in order to avoid the metaphysical baggage involved in the use of the word “soul.” They propose that the mind becomes aware of brain states by “clairvoyantly” monitoring neural activity. They propose that volitional activity is accomplished through the

Obvioiusly, in Thouless and Wiesner’s theory, there must be some force restricting the vast majority of the Shin’s interactions to the brain, corresponding in some sense to the philosopher Henri Bergson’s (1914) suggestion that the brain acts as a filter, admitting primarily need-relevant information to the mind.  After all, it would not be evolutionarily advantageous to be a clairvoyant spectator of a basketball game in progress as one drives one’s car at 80 miles an hour on the freeway past the stadium.  Such considerations led the psychoanalyst Jan Ehrenwald (1977, 1978) to suggest that the reason for the weakness of most psi effects in the laboratory is that they must make use of “flaws” in the Bergsonian filter, whereas psi phenomena in real life tend to be need-relevant and adaptive.

Ehrenwald hypothesized that the psi-filter resides in the reticular activating system (RAS) of the brain stem, presumably because this area acts as a filter for many sensory processes, although he conceded that areas of the midbrain, limbic system, and the frontal and temporal lobes may be involved in the filtering process.  Of course, much filtering of normal afferent sensory impulses occurs before these impulses even reach the central portion of the brain, suggesting that filtering may occur on whatever afferent pathway underlies ESP (which may not even be a physical pathway based on our current understanding of what is “physical”).  Ehrenwald provided little in the way of hard evidence that the psi-filter is located in the RAS, so this hypothesis is really a conjecture on his part.

Ehrenwald compared percipients’ sketches in successful telepathy experiments involving the attempted transmission of line drawings to the drawings of brain-damaged patients, and he suggest that like brain-damaged patients (as least those with primarily left hemisphere involvement), the telepathic subject may be relying on the right hemisphere of the brain.  However, this hypothesis would seem to be contradicted by the often-reported phenomenon of dissociation (the breaking up of the target picture into its components) in the early telepathic drawing experiments, such as those reported by Warcollier (1948/1963).  Such dissociation would seem to more akin to that produced by damage to the spatially- and holistically-oriented right hemisphere than by damage to the more verbally-oriented and “linear” left hemisphere.

Ehrenwald suggested that one should expect higher psi scoring among brain-damaged patients (due to disruption of the psi filter) than among normal subjects.  In support of this contention, he cites successful psi experiments with retarded patients and patients suffering from concussions.  He also hypothesized that some schizophrenic patients may be suffering from “psi pollution” due to damage to the filter.  However, Rogo (1975) reported finding no higher psi-scoring among psychotics that among normal subjects in a review of the experimental literature.   

There is a smattering of parapsychological evidence that has some relevance to Thouless and Wiesner’s theory.  Honorton and Tremmel (1979), for instance, conducted a study in which they found that success in a PK task was positively correlated with the subject’s ability to control his own brain waves. They interpret their finding as providing support for Thouless and Wiesner’s internal psi model of mind-brain interaction.  On the other hand, if it is assumed that the Shin has a limited attentional capacity, one might anticipate that subjects would be successful in a PK task precisely when their attention was not devoted to controlling their brain waves, and that therefore a negative correlation would be expected. Just such a prediction was in fact made by Rogo (1980), citing Roll’s finding of a high incidence of epilepsy among presumed poltergeist agents (Roll, 1978a) in support of the view that successful PK is accompanied by the disruption of normal brain processes.  It should also be noted that a study by Varvoglis and McCarthy (1982) failed to replicate Honorton and Tremmel’s results. Indeed, Varvoglis and McCarthy found that significant PK effects occurred only during trials in which the subjects performed poorly on the brain-wave control task.

Other evidence that the mind might be capable of influencing brain activity is provided by Baumann, Stewart and Roll’s (1986) finding that humans could psychokinetically influence the firing rate of the pacemaker neuron of the marine snail Aplysia and Rein’s (1986) finding that activity of monoamine oxidase, an enzyme regulating neurotransmitter concentrations, could be influenced through psychokinesis.  Neither of these studies was methodologically perfect, however.

Evidence from telepathy experiments that percipients perceive specific neurological events in the brains of the senders would give support to Thouless and Wiesner’s theory of telepathy.  As discussed briefly above, Rene Warcollier (1948/1963) reported evidence of what he called “dissociation” in his experiments on the telepathic reception of drawings.  This dissociation consisted of the percipient’s drawing fragments of the target (such as isolated corners of a line drawing), suggesting that the percipient may have been responding to individual eye fixations on the part of the sender or even to “feature analyzers” in the sender’s brain.

John Beloff (1980) has expressed doubt that someone could read the idiosyncratic “neurological code” employed by someone else’s brain.  Beloff’s objection would suggest that telepathic interaction must take place at a higher, mental level, rather than involving the direct reading of another person’s brain state.  Incidentally, Beloff himself has proposed a model of mind-brain interaction very similar to that of Thouless and Wiesner, except that Beloff further conjectures that the mind or Shin might survive the death of the brain with some of its memories intact (Beloff, 1990).

Some further support for Thouless and Wiesner’s theory, in particular for the concept of kappa-telepathy, is provided by the rather voluminous literature reporting successful attempts to influence the behavior of living organisms using psi (which is sometimes interpreted as evidence of psychokinesis and sometimes as evidence of telepathy).

Implications of split-brain research. The results of research with split-brain patients pose severe difficulties for a naive interpretation of any theory in which a single immaterial mind is assumed to interact in a global manner with large areas of the brain, as in Thouless and Wiesner’s Shin theory.  As discussed in Chapter 1, in some cases of intractable epilepsy, a drastic surgical procedure involving the severing of the neural connections between the two cerebral hemispheres may be performed in order to stop electrical seizures of the brain from spreading from one hemisphere to the other. This procedure involves cutting the fibers of the corpus callosum, a bundle of nerves directly connecting the two hemispheres of the brain. This operation is called a commisurotomy or callosectomy. The act of severing the corpus callosum seems to result in a person with two separate spheres of consciousness, one residing in the right hemisphere and one residing in the left hemisphere.  If one were to have such a patient visually fixate a point on a movie screen and then flash a picture of a hammer in his left visual field and a picture of a pencil in his right visual field, the two hemispheres would have different ideas about what was shown on the screen. If you asked the patient what he saw, he would usually say “a pencil,” because the brain structures involved in the production of language generally reside in the left cerebral hemisphere and information from the right visual field is funneled into the left hemisphere.  On the other hand, if you asked the patient to pick up the object that he saw on the screen with his left hand (which strangely enough is controlled by his right hemisphere), he would pick up the hammer.  (His right hand may very well be reaching out and trying to guide the left hand to the pencil, however.) Similarly, if you blindfolded him and gave him a chesspiece to hold in his left hand, he would not be able to describe verbally what object he had been holding (as the sensory information from the left hand is fed to the right hemisphere and linguistic ability is located in the left).  He would, however, be able to identify the chesspiece by using his left hand to pick it out from an array of objects on a table.

These findings pose grave difficulties for a naive theory of mind-brain interaction of the Thouless and Wiesner type. Under Thouless and Wiesner’s theory, the patient’s Shin should be able to overcome the above communication gap. Through clairvoyant perception of the sensory information in the right hemisphere and psychokinetic influence of the language centers in the left hemisphere, a split-brain patient should be able to give a verbal description of an object held in the left hand. That such an effect is not observed would seem to constitute devastating evidence against Thouless and Wiesner’s theory. Two means of saving the theory are apparent, however.  First, it could be assumed that the mind’s influence on the brain is restricted to the facilitation and inhibition of the transmission of information across synapses.  (Synapses are microscopic gaps between neurons. When a neuron fires, it releases chemicals called neurotransmitters that travel across the synapse. When the neurotransmitters reach the postsynaptic neuron, they may bind to receptors on its surface. These neurotransmitters may either increase or decrease the probability that the postsynaptic neuron will fire.)  Under this version of Thouless and Wiesner’s theory, the mind would be unable to integrate the activity of the brain in the absence of the corpus callosum and might be assumed to experience two alternating or parallel, but independent, streams of consciousness.

Further discussion of the notion of multiple selves in split-brain patients will be postponed until Chapter 7, in which we consider the notion of the “self” and its relation to brain activity.

Psi and Evolution

In recent years, an increasing amount of attention has been paid to the possible role of psi in the evolution of biological organisms.  Levin (1996, 2000) notes that one argument against the reality of psi is that such abilities would have been vastly improved over the course of evolution and should by now be stronger than they appear to be.  They should also be in widespread use among organisms.  Levin, however, observes that psi is likely a feature of the mind rather than the brain.  Thus, it is only indirectly affected by the genes and therefore may be uncoupled from improvement via biophysical evolution.  He suggests that the lack of improvement of psi abilities over the course of biological evolution speaks against mechanistic explanations of psi phenomena.  

Taylor (2003) responds to Levin’s assertion that because psi abilities are weak, they may not be subject to normal evolutionary processes.  He notes that the following assumptions must be met in order for there to be an evolutionary explanation of psi:


 Psi has a genetic basis.

 Psi ability is variable among the population.

 Possession of a certain amount of psychic ability confers biological fitness on an individual.


Taylor notes that the evolution of well-controlled psi may involve huge changes in the makeup of an organism rather than a gradual change as one might expect on the basis of evolution, and he compares the evolution of psi abilities to the evolution of a wheeled organism.  He suggests that psi abilities may operate unconsciously due to the competing information-processing demands of monitoring one’s physical environment and that psi-scanning may be intermittent because of such demands.  He proposes that psi abilities may provide warnings of impending disasters as well as providing a means of monitoring the behavior and welfare of close biological relatives.  He notes that psi ability in laboratory situations is correlated with the psychological trait of vigilance (ability to see a threat in a degraded sensory image), citing the work of Watt and her co-workers in this regard (Watt & Gissurarson, 1995; Watt & Morris, 1995).  He also cites Radin’s research on precognitive “presentiment” responses to emotional targets (e.g., Radin 1997b, 2003).  As to the question of why people do not use psi more often to avoid disasters, Taylor replies that people often do not avoid disasters even when provided with compelling sensory information.

Beloff (2002) notes that if researchers can detect psi abilities in “lower” species, this may offer clues as to when, in the course of evolution, consciousness first appeared.  This of course implicitly links psi abilities to consciousness.  The evolution of consciousness in supposedly insensate matter is of course one of the deepest (and as yet unanswered) questions facing not only neuroscience, but perhaps physics itself.

Finally, McClenon (2004) hypothesizes that the ability to enter dissociative states on the part of some members of tribal organizations may have been passed on due to the psi-mediated success of such persons when acting as shamans.  McClenon notes that shamanism, in which the practitioner enters into a trance-like state to contact spirit helpers, is universal among hunter-gatherer societies.  He notes that cave art suggests that shamanism has been practiced for over 30,000 years and has provided the basis for all later religions.  He hypothesizes that the capacity to enter dissociative/hypnotic states could not increase indefinitely because such traits have negative consequences (for instance, fantasy-prone individuals often suffer from psychosomatic illness as well as other forms of dissociative disorder).   To some extent, McClenon’s remarks echo Henri Bergson’s observation about the need for a psychic filter to screen out competing psi information and keep the organism’s focus on stimuli that are directly pertinent to the organism’s biological survival.   


One of the major developments in the past half-century has been the growing realization that psi phenomena need not be in conflict with established laws of science. The past two decades have seen the experimental confirmation of the principle of nonlocality in quantum mechanics and the growing realization of the importance of that principle for a theory of psi phenomena.  At present, theorizing in parapsychology is held back by the lack of a reliable data base and repeatable psi effects upon which a powerful theory of psi might be constructed and refined. Thus, many of the theories in this chapter represent mere presentations of “theoretical environments,” within which more specific theories yielding more powerful experimental predictions might be constructed.

This chapter has been concerned primarily with theories aimed at explaining how psi information might be transmitted and with the implications of psi phenomena for our understanding of the nature of mind, matter, space and time. 

Now we turn inwards to the examination of the nature of the conscious self and its possible survival of the death of the physical body.  Chapter 6 concludes our study of parapsychology by examining the evidence that the personality or a portion thereof may survive death.  The evidence for such survival will include ghosts and apparitions, dreams, out-of-body and near-death experience, the evidence from mediumship and the evidence for reincarnation.  As noted in Chapter 0, survival of the mind with major portions of the human personality intact is improbable in view of the fact that human emotions, memories and beliefs appear to be intimately dependent on brain processes in light of modern neuropsychological research.  In Chapter 7, we will revisit the nature of the self and examine the possibility that the true self, in the form of a center of pure consciousness, may survive death and may in fact be only temporarily associated with any given physical body.  

6. Death and the Mind

 Who are we?  What are we?  We emerge, seemingly from nothingness, into the physical world. Is it to nothingness that we return? Are we our physical bodies? Our personalities? Or are we a field of pure consciousness through which our thoughts, sensations and emotions flutter like so many butterflies?

Much of the parapsychological evidence for the survival of death, including that from mediumship and reincarnation cases, suggests that the mind is able to survive death with large portions of its memories, skills and personality intact. There is, however, an overwhelming amount of evidence that one’s emotions, patterns of behavior and cognitive skills are intimately tied to the state of one’s brain. For instance, damage to the right hemisphere of the brain can turn a depressed musician into a happy-go-lucky, tone-deaf individual.  Damage to the frontal lobes of the brain can turn an upright citizen into a raincoat-opening exhibitionist. Surely the removal of one’s entire brain at death would change one’s state of consciousness profoundly!

Memory also appears to be intimately dependent on brain structures. There is an abundance of evidence that damage to the hippocampal and thalamic areas of the brain can destroy one’s ability to store new long-term memories. People with such a condition live in a kind of dream state. They will not recognize the nurse who has been taking care of them daily for years, but will greet him each time as if meeting someone new. There is also an increasing amount of evidence that some memories may be stored in localized regions of the brain and may be erased when these areas are damaged.  For instance, in a bilingual patient who speaks, say, English and Greek, it is possible to interfere with his inability to speak Greek by electrically disrupting one area of his brain and to interfere with his ability to speak English by disrupting another area.  (Ojemann, 1983).  

Michael Gazzaniga (1989) describes a case in which a localized brain lesion rendered a woman incapable of naming the color of red fruits, although she could name the color of non-red fruits such as bananas as well as of red objects such as fire engines.  Kinsbourne & Warrington (1964) report a case in which a very circumscribed brain lesion rendered a patient unable to name colors altogether.  Localized memory traces have also been demonstrated in nonhuman subjects. Memory for a conditioned eyeblink response has, for instance, been shown to reside in the cerebellum of the rabbit (see Squire, 1987; and Krupa, Thompson & Thompson, 1993).  There is also a considerable body of evidence that the storage of memories is dependent on changes in the synaptic connections among the neurons of the brain (see Squire, 1987; Baringa, 1990; Zhong & Wu, 1990; Rose, 1992; and Fanselow, 1993).

Even the avowed dualist Sir John Eccles believed that long-term memories are stored as changes in synaptic connections between neurons. Eccles did, however, feel compelled to postulate the existence of a second, nonphysical memory system in which “recognition memory” (which monitors the correctness of recalled information) resides, even though he maintained that memories of the details of the events in one’s life are physically stored in the brain and hence lost at death (Eccles, 1979; Eccles & Robinson, 1984).  The prominent reincarnation researcher Ian Stevenson (1981) likewise proposes that there are two memory stores, one physical and one nonphysical. He suggests that, although brain mechanisms may control access to all memories before death, this does not prove that the memory traces themselves are physical.

The parapsychologist Alan Gauld (1982) has also questioned whether memories are stored as physical traces in the brain, noting that memories are sometimes gradually recovered after brain damage.  David Lund (1985) makes the argument that the brain may be the transmitter rather than the generator of consciousness, a view that goes back to William James (1898/1992).  Under this analogy, a damaged brain may simply be unable to receive the signal from an intact consciousness. On the other hand, Barry Beyerstein (1987) has argued that a nonphysical mind should be able to compensate for the effects of brain damage.  Why, he asks, can the mind allegedly separate from the body in an out-of-body experience and perceive the environment if it cannot overcome perceptual deficits caused by brain damage (such as blindness arising from damage to the visual cortex)?

What Could Survive?

Obviously, the physical body does not survive the death of the physical body. As we have just seen, it appears unlikely that our memories and personalities could survive the dissolution of our physical brains.  What, however, constitutes our essential selves? Are we our bodies? Our personalities and memories? Or are we in fact pure centers of consciousness with the remaining aspects of our personalities just so much baggage to be checked (and inevitably lost) as we board the celestial starship for yet another ride?

Many philosophers see the physical body as an essential part of one’s self.  In Terence Penelhum’s view, for instance, it makes no sense to talk about people surviving their deaths in some sort of disembodied state.  If such a disembodied ghost were to communicate through a medium and relate memories of the person’s life, this would prove nothing according to Penelhum, as memories might be illusory. He thinks that people can only be identified on the basis of their physical bodies and that therefore it makes no sense to talk about people surviving the deaths of those bodies (Penelhum, 1987). Of course, physical appearances can also be deceptive.  Persons can disguise themselves  as someone else, for instance.  Thus, it is not clear that physical appearance is a foolproof means of identifying a person either. 

Peter Geach (1987) is another philosopher who maintains that personality traits and memories are not a sufficient basis to identify a person. He compares the transfer of personality traits and memories from one body to another, such as might occur in one of Stevenson’s reincarnation cases, to the spreading of a disease.   

The noted philosopher Antony Flew (1987, 1991) also contends that immaterial souls would not be identifiable. In Flew’s opinion, the idea that a person survives death can only be made intelligible if you assume that people possess some sort of quasi-physical astral body, on the basis of which they could be identified.  Flew views the ideas of disembodied survival and incorporeal souls as incoherent notions. He maintains that the word “person” refers to a flesh and blood creature and that it therefore makes no sense to talk of a person surviving the death of his physical body.

All of these writers contend that some sort of physical body is necessary in order to establish the continuity of personal identity. It is not clear why we should put so much more stock in physical appearance than in mental appearance.  If we are in fact our physical bodies, then what survives in the long run is a fossilized skeleton, seemingly devoid of consciousness (although the panpsychists may give us an argument on this point) and a dispersed collection of elementary particles, some of them “reincarnated” in animals, plants and other living things and some of them finding lodging in inanimate objects, also seemingly devoid of consciousness (but again, as the panpsychists may argue, perhaps associated with a rudimentary form of “protoconsciousness”). 

We now turn to an examination of the evidence amassed by psychical researchers that the human personality or some portion thereof survives the death of the physical body.  Such survival is a central tenet of many major religions such as Islam and Christianity as well as the mythological and shamanistic traditions.  As already noted, the findings of neuroscientific research in the past half-century have established an intimate dependence of the personality, including one’s memories, thoughts and emotions, on the physical state of the brain.  This body of research makes the survival of the personality of the death and dissolution of the brain a much more improbable prospect that it was in the days of the early physical researchers such as Frederic W. H. Myers and William James.  Nevertheless these researchers and their “descendants,” including a significant minority of the parapsychological community today, have amassed a considerable body of evidence that the human personality, or some portion thereof, may survive the death of the physical body.  This evidence includes: out-of-body and near-death experiences; hauntings; apparitions; dreams; some poltergeist cases; evidence provided by mediums and “psychics;” cases suggestive of “obsession” and reincarnation, in which people report memories of past lives or are seemingly influenced by discarnate spirits; and miscellaneous attempts to photograph, weigh, record or otherwise physically measure and detect souls or spirits.

 In Chapter 7, we will turn to an examination of the nature of the self, and in Chapter 8 explore the possibility that the self, construed as a center of pure consciousness, could survive the death of the physical body.

Out-of-Body Experiences.

We begin our study with possible glimpses of the afterlife that occur prior to the actual death of the physical body, that is with out-of-body experiences (OBEs) and near-death experiences (NDEs).  NDEs often incorporate OBEs as well as apparent visions of another realm and its inhabitants.  

In OBEs, people are apparently able to separate from their physical bodies and travel to near and distant locations.   OBErs often report that they experience themselves encased in some sort of “astral body,” usually resembling the physical one (often even wearing ”astral clothes”) during these wanderings.  

Some people experience but one OBE in their lifetimes, whereas others experience OBEs repeatedly. In some cases, the OBE occurs without any conscious effort to induce it; in others, the OBE occurs as a result of a deliberate induction or incubation process.  The following is an example of the former type of OBE and is taken from the collection of Susan Blackmore, an unusual researcher who is at once one of parapsychology’s harshest critics and at the same time a prominent investigator of OBEs:

I crossed the road and went into a well-lit wood. My distant vision began to blur and within five or ten seconds I could only see a distance of a few feet, the rest was “fog.”

Suddenly my sight cleared and I was looking at the back of myself and the dogs from a position eight or ten feet behind myself and about a foot higher than my height. My physical self had no sight or other senses and it was exactly as if I was simply walking along behind some-one, except that some-one was me… (Blackmore, 1982a, p. 9).  

The following case is provided by Hornell Hart:

 Sometime before 1907, a well-known physician in New York City…was on a river steamer…He had been having some curious sensations of numbness and of psychological detachment for some days.  During the night on the steamer he found that his feet and legs were becoming cold and sensationless.  He then ‘seemed to be walking in air’…In this state he thought of a friend who was more than 1000 miles distant.  Within a minute he was conscious of standing in a room…and his friend was standing with his back to him.  The friend turned, saw him and said: ‘what in the world are you doing here?  I thought you were in Florida,’ and he started to come toward the appearer.  The appearer heard the words distinctly but was unable to answer.

Then he re-entered his physical body.

On the next day he wrote a letter to the distant friend whom he had perceived in this excursion.  A letter from the friend crossed his in the mail, stating that he had been distinctly conscious of the appearer’s presence, and had made the exclamation which the appearer heard (Hart, 1954, p. 133; as cited by Steinkamp, 2002, p.72).

 Such cases, in which the OBEr’s presence is felt or seen by witnesses at the remote location are sometimes called “reciprocal hallucinations” (a term that is perhaps somewhat prejudicial as to the explanation of the phenomenon).  

Involuntarily experienced OBEs can occur for no apparent reason, as in the first case above, or they can be the result of fatigue, drug intoxication, sensory deprivation, and psychological or physical stress, as in the second case. A most dramatic form of out-of-body experience occurs when a person is rendered nearly unconscious and near death but is able to witness attempts to revive or resuscitate her physical body from a perspective well above the body. Often such a person feels herself being pulled back into the body at the moment of successful resuscitation. Such cases may be regarded as one form of the near-death experience. Near-death experiences will be discussed in greater detail in the next section.

Obviously, there may be nothing paranormal about OBEs in and of themselves. They may simply be a kind of delusion, hallucination or dream in which one experiences oneself outside of one’s body.  OBEs have been of interest to parapsychologists for at least two reasons. First, they suggest the existence of a mind or soul that is capable of traveling beyond the confines of the physical body in ways that are not explainable by current theories of physical science.  Also, many people experience themselves as being encased in a secondary body while in the OBE state.  Often this secondary body takes the form of a duplicate of the person’s ordinary physical body.  This has suggested to some researchers that there may exist a nonphysical or quasi-physical “astral body” in which the soul or mind may be housed during its extrasomatic sojourns.  If so, this body would be of a type unknown to current theories of science.  Of course, the fact that people experience themselves as possessing astral bodies could be explained in terms of hallucination and fantasy, unless some means of detecting such astral bodies with physical instruments could be devised. 

Several parapsychologists have in fact attempted to use some sort of physical measuring device to detect astral bodies, as will be discussed in greater detail below.  Most parapsychologists remain skeptical about the reality of astral bodies due to the fact that people generally perceive themselves as being clothed while in the astral state.  This would seem to indicate that astral bodies are merely hallucinations (at least as literally perceived), unless one wishes to assume that clothes have astral bodies too!

A second reason parapsychologists have become interested in OBEs is that there are many anecdotal reports of persons becoming aware of information during out-of-body travel to remote locations that would have been inaccessible to them at the location of their physical bodies during the OBE.  For instance, the well known psychiatrist and consciousness researcher Stanislav Grof (1990) describes a case in which a woman who was undergoing cardiac arrest felt herself leaving her body and exiting from her hospital room.  She then seemed to travel in the out-of-body state to a point outside of the hospital, and she felt herself rise to a point near a tennis shoe that was sitting on a ledge near a third floor window.  A subsequent search revealed that there really was such a shoe on the ledge.  (A determined skeptic, could of course always argue that the patient might have caught a glimpse of the shoe when she was admitted or when entering the hospital on a previous occasion, as her admission took place at night.)  Incidentally, Roach (2005) reports two similar cases involving a red shoe and a plaid shoe (the latter being understandably noticeable even to one in a comatose state).  Roach observes that the “OBE traveller’s affinity for foot wear must remain a mystery” (Roach, 2005, p. 277).

The following case, taken from the journal of a British army officer (Ogston, 1920), is cited by Cook, Greyson and Stevenson (1998):

In my delirium night and day made little difference to me.  In the four-bedded ward where they first placed me I lay, as it seemed, in a constant stupor which excluded the existence of any hopes or fears.  Mind and body seemed to be dual, and to some extent separate.  I was conscious of the body as an inert, tumbled mass near a door; it belongs to me but it was not I.  I was conscious that my mental self used regularly to leave the body…until something produced a consciousness that the chilly mass, which I then recalled was my body, was being stirred as it lay by the door.  I was then drawn rapidly back to it, joined it with disgust, and it became I, and was fed, spoken to, and cared for.  When it was left again I seemed to wander off as before….

In my wanderings there was a strange consciousness that I could see through the walls of my building, though I was aware that they were there, and that everything was transparent to my senses.  I saw plainly, for instance a poor R. A. M. C. [Royal Army Medical Corps] surgeon, of whose existence I had not known before, and who was in quite another part of the hospital, grow very ill and scream and die; I saw them cover his corpse and carry him softly out on shoeless feet, quietly and surreptitiously, lest we should know that he had died, and the next night - I thought - take him away to the cemetery.  Afterwards, when I told these things to the sisters [senior nurses], they informed me that all this had happened….(Cook, Greyson and Stevenson, 1998, p. 383).

Cases such as these have led parapsychologists to perform experiments in which people have tried to travel to a remote location in the out-of-body state in order to identify target materials placed at that location. These experiments will be discussed later in this section. Of course, if these experiments are no more successful than ordinary ESP experiments, it would not be necessary to assume that the subjects literally traveled out of their bodies; instead, one could simply assume that the subjects used their ESP abilities to identify the target.

On rare occasions, witnesses present at the location to which an OBEr has traveled in the out-of-body state may experience an apparition of the OBEr or otherwise become aware of the OBEr’s presence.  Such cases are sometimes given the (somewhat prejudicial) label “reciprocal hallucinations,” because both the OBEr and the witness have mutually consistent experiences, as in case of the physician on the steamer presented earlier in this section. 

Perhaps the most famous instance of reciprocal hallucination in the annals of psychical research is the Wilmot case, reported in Myers (1903).  It has in fact become almost obligatory to cite the Wilmot case in an introductory work on parapsychology.  The events in this case occurred in the 1860s, so it is a very old case indeed.  A Mr. S. R. Wilmot was sailing from Liverpool to New York when his boat passed through a severe storm.  During the storm, he had a dream in which he saw his wife come into the door of his stateroom, hesitate and then bend down to kiss and caress him.  Upon awakening, his fellow passenger William Tait said to him, “You’re a pretty fellow to have a lady come and visit you in this way.”  When Wilmot pressed him for an explanation, Tait said that, as he lay awake in the upper bunk, he saw a woman enter, hesitate and then kiss Mr. Wilmot.

When Mrs. Wilmot greeted him upon his arrival in Watertown, Connecticut, she almost immediately asked him if he had received a visit from her on the night in question.  She said that she had been anxious about the severity of the weather and the reported loss of another vessel.  She had lain awake for a long time and at about 4:00 A.M. she had the sensation of leaving her physical self and traveling across the stormy sea until she reached her husband’s stateroom.  She said she saw a man in the upper berth looking right at her and so for a moment she was afraid to go in.  But she did enter, kissed and embraced her husband and then departed.

One major drawback to this case is that the principal informants did not give their testimony until about twenty years after the events in question.

Alan Gauld (1982, pp. 222-223) provides a more recent case of reciprocal hallucination. He quotes from a statement sent to the American Society for Psychical Research by a 26-year-old woman from Plains, Illinois. This woman experienced a dream on the morning of January 27, 1957, in which she seemed to travel to the home of her mother in northern Minnesota, 926 miles away:

After a little while I seemed to be alone going through a great blackness. Then all at once way down below me, as though I were at a great height, I could see a small bright oasis of light in the vast sea of darkness. I started on an incline towards it as I knew it was the teacherage (a small house by the school) where my mother lives.… After I entered, I leaned up against the dish cupboard with folded arms, a pose I often assume. I looked at my Mother who was bending over something white and doing something with her hands. She did not appear to see me at first, but she finally looked up. I had sort of a pleased feeling and then after standing a second more, I turned and walked about four steps.

Gauld also quotes a letter the woman received from her mother:

I believe it was Saturday night, 1.10, 26 January, or maybe the 27th. If would have been 10 after two your time. I was pressing a blouse here in the kitchen…. I looked up and there you were by the cupboard just smiling at me. I started to speak and you were gone. I forgot for a minute where I was. I think the dogs saw you too. They got so excited and wanted out—just like they thought you were by the door—sniffed and were so tickled.

Your hair was combed nice—just back in a pony tail with the pretty roll in front. Your blouse was neat and light—seemed almost white. [Miss Johnson confirmed in correspondence that this was an accurate description of her subjective appearance during the OBE.]

It is difficult to decide whether to classify this experience as a dream or as an OBE. 

Philosopher Michael Grosso (1976) suggests that the OBE is just one in a continuum of states of consciousness encompassing schizophrenic, meditative, drug, reverie and dream states. He further argues that ESP, “traveling clairvoyance” (in which a person seems to project his mind to a distant location and to become aware of events happening at that location), and the OBE may merely represent three aspects of the same process.

There are a few other states of consciousness that also bear a resemblance to the OBE.  Psychiatrists use the term “depersonalization state” to refer to instances in which a person feels himself to be detached from his emotions, actions and even his body.  A person undergoing feelings of depersonalization may describe himself as hovering over his body and watching his body perform actions without really being a part of them himself.  Janet Mitchell (1981) argues that depersonalization states differ from OBEs in that depersonalization states, unlike OBEs, may involve feelings of derealization (in which one’s environment is felt to be unreal).  It should also be noted that the flattening of affect (that is, diminished emotional reactions) that is often a characteristic of depersonalization states is not usually reported by people undergoing OBEs.

 Irwin (1996) notes that the reporting of OBEs is correlated with the reporting of childhood traumas, and he suggests that a tendency toward dissociation and the experiencing of OBEs may a type of defense mechanism.  Irwin (2000) also reports evidence of elevated somatoform dissociation in persons reporting OBEs.  In addition, he found that OBErs scored more highly on the trait of psychological absorption (e.g., the ability to “lose” oneself in a book one is reading).  

Autoscopy is a state in which one perceives a double or apparition of oneself in the external environment, such as across the street.  Autoscopy thus differs from the OBE in that the person’s location of consciousness seems to remain located in the physical body rather than in the double. Tyrrell (1953, p. 144) reports the case of Archbishop Frederic, who saw an apparition of himself after awakening from a deep sleep.  He stated that the apparition was “luminous, vaporous and wonderfully real” and that the apparition was looking at him.  This state lasted for a few seconds, after which the apparition disappeared. A few seconds later, the specter reappeared, only to vanish once again after a few more seconds.

Doppelgangers. Closely related to autoscopy is the experience of the “doppelganger.”  “Doppelganger” is a German word used to refer to the apparition of a living person who is not present.  In many reported cases, the doppelganger presages the arrival of the person and is often reported to perform acts later performed by the real person.  Andrew MacKenzie cites the case of Canon J. B. Phillips, whose wife had gone with an ambulance to the hospital to see after an injured person.  Phillips reported hearing a car driving up the road to his chalet. He then heard his wife’s voice saying “Thank you very much, goodnight,” and he said he then “distinctly” heard the slamming of the car door. He ran out to welcome his wife, but there was no one there at all.  About an hour later, these auditory events were replayed, but this time for real (MacKenzie 1971, p. 82).  Like autoscopy, the doppelganger experience differs from the OBE in that the person’s consciousness remains in the physical body, not in the appearing double.

Bilocation.  The phenomenon that will perhaps most strain the reader’s credulity is that of bilocation, in which a person, often a Christian, Hindu or Buddhist saint, is experienced as being physically present at two distinct physical locations at the same time.  For example, on one night in 1774, the monk Alphonso de Liguori was reported to have been seen simultaneously in his cell and at the bedside of the dying Pope Clement XIV about 100 miles away. (Mitchell, 1981, p. 106).  Susan Blackmore relates the case of a schoolteacher in the 1840s who evidently frequently appeared in duplicate (Blackmore, 1982a, p. 12). The students would see two copies of her standing side by side at the blackboard and also at dinner.  Two copies of her would also be seen performing activities at different locations around the school.  Blackmore reports that this teacher was fired from her job. One would have thought the administration was getting quite a bargain!  Finally, Osis and Haraldsson (1977c) report on two Indian swamis, Sai Baba and Dadajai, who have been reported to bilocate in more recent times.

Bilocation is a very infrequently reported phenomenon and few parapsychologists would put much credence in it.  Bilocation appears to differ from the OBE in that the double appears to be a solid physical object that does not vanish into thin air and that is capable of physical interaction with its environment.  Also, as both copies of the self are reported to be capable of performing complex acts, bilocation would seem to involve a duplication of consciousness as well as of the body.  It might of course be possible to explain such phenomena by assuming that the person’s mind is at least temporarily split into two distinct subpersonalities.  This would be a type of mental, as well as physical bilocation that is not usually reported in OBE cases.

Explanations of the OBE

Theories concocted to explain OBEs may be divided into roughly two types.  Theories of the first type postulate that the OBE involves an “exteriorization” or projection of some (possibly nonphysical) aspect of the person outside of the physical body.  This projected aspect is variously conceptualized as the mind, the soul, or some form of quasi-physical “astral body.”  Theories of this type date back to at least 5000 B.C., the time of the creation of portions of the Egyptian Book of the Dead (Mitchell, 1981).  The ancient Egyptians postulated the existence of a ka, a form of astral body inhabited by the ba, or soul, after death. Likewise, the Tibetan Book of the Dead postulates the existence of a Bardo-body to house the soul after death.  Some Mahayana Buddhists subscribe to the doctrine of kayatraya, postulating three bodies.  This multiple body principle was later adopted by the religion of Theosophy, which has its roots in Buddhism.  Non-Western shamanistic traditions also incorporate the notion of out-of-body travel, as in the case of the Australian aborigines, whose “clever men” are alleged to be able to project themselves at will.

Based on his analysis of a large number of reported out-of-body experiences, Robert Crookall (1970) was led to propose that the astral separation takes place in two stages.  In the first stage, the soul or “soul body” is housed in a quasi-physical “vehicle of vitality.”  When in this state, the OBEr experiences a gloomy Hell-like environment.  The second stage, which occurs after the soul body is successful in shedding the vehicle of vitality, is characterized by a great sense of peace, beauty and tranquility.  Several writers in the early days of OBE research (e.g., Muldoon & Carrington, 1929) were led, based on anecdotal reports, to postulate the existence of a “silver cord,” or sometimes cords, connecting the astral and physical bodies, often through the head or solar plexus.  Modern OBErs are much less likely to see such cords, however.   

Janet Mitchell (1981) has proposed that dreams in which one is falling are related to the process of reentry of the astral body into the physical body.  She also suggests that sudden jerkings of one’s body when falling asleep may be due to the astral body’s suddenly moving back into “coincidence” with the physical body, an idea that had been earlier proposed by Sylvan Muldoon (Muldoon & Carrington, 1929).  It should be noted, however, that such sudden jerkings are commonly called myoclonias and that several normal explanations have been proposed to account for them.  One such explanation ascribes myoclonias to the withdrawal of the cerebral cortex’s control over spinal motor neurons (this withdrawal is a necessary component of the development of the “sleep paralysis” that prevents one’s body from acting out one’s dreams at night).

The OBE has been taken by many to suggest that some portion of the human personality may be capable of surviving outside of the physical body and hence capable of surviving the death of that body.  Indeed, Thomas Metzinger (2005) has argued that the very concept of the soul derives from OBEs, which he notes is a widely experienced, transcultural phenomenon.  

William Roll (1982b) has warned that survival in the form of an astral body may be sharply limited in time, as the number of reported crisis apparitions declines steeply with the time interval since the death of the appearing person (assuming that such apparitions are perceptions of astral bodies).  Rodger Anderson (1981) observes that the OBE does not constitute unequivocal evidence for the mind’s survival after death, as the site of consciousness might occasionally extend beyond the body yet still perish with the body.  He also notes that the silver cord need not be thought of as a means of animating the physical body, as some advocates of astral projection believe, but may instead be a means of animating the astral body by serving as a conduit for the delivery of energy from the physical body.

Perhaps the most devastating argument against the interpretation of the OBE as the literal projection of an astral body is that people are generally unable to identify stimuli placed at locations to which they have supposedly traveled in the out-of-body state in experimental situations, as will be discussed in greater detail below. Attempts to detect a quasi-physical astral body at its projected location through the use of physical instruments will also be discussed below.

The second category of theories includes those that propose a largely psychological explanation for the OBE, several of which have already been discussed. The psychiatrist Jan Ehrenwald (1974) viewed the OBE as an attempt to assert the reality and autonomous existence of the soul and as a psychological defense against the threat of extinction at death.  Russell Noyes (1972) likewise sees the OBE as a form of psychological “negation of death.”  On the other hand, the existing evidence indicates little relationship between anxiety about death and the reporting of OBEs (e.g., Myers, Austrin, Grisso & Nickeson, 1983; Smith & Irwin, 1981).   

D. Scott Rogo (1978), Carl Sagan (1977), and Barbara Honegger (1983) have each suggested that the OBE (and the closely related phenomenon of the near-death experience or NDE) may be based on a rebirth fantasy or a reliving of the birth process.  Some of the evidence they cite in support of this hypothesis includes the experiencing of tunnel-like passageways during OBEs and NDEs, as well as the cord-like connection between the physical body and the astral body reported by some OBErs (this cord being taken as reminiscent of an umbilical cord).  There is some reason to be skeptical of this hypothesis.  First, there is considerable doubt in the scientific community that the process of birth can be remembered in any detail, due to the incomplete myelinization of the neonatal brain. Second, Susan Blackmore (1983a) has attempted to test the hypothesis that persons born by Cesarean section (and hence who have not experienced a classical birth process to relive) will report fewer OBEs than persons born by vaginal delivery.  She found no relationship between the reporting of OBEs and type of birth in her survey.  It remains possible of course that OBEs may be related to fantasies or archetypal ideas about birth even if they do not involve a literal reliving of the birth process.

John Palmer (1978, 1986) has proposed that OBEs may be triggered by changes in the body concept arising from altered patterns of feedback from nerves monitoring the positions of muscles and limbs. Such altered proprioceptive feedback might occur in sleep, in conditions involving physical trauma, or following the administration of anesthetics.  In Palmer’s view, these changes in body concept may threaten the normal concept of the self or sense of individual identity.  As a result, the person’s unconscious defenses are activated in order to reestablish a sense of identity, and this reestablishment may take the form of an OBE.  When the normal body concept is reestablished, the OBE ends.

Susan Blackmore (1984b) proposes a psychological model of the OBE that is quite similar to that proposed by Palmer.  Like Palmer, she suggests that the OBE represents a mental model of the world that is constructed in response to a breakdown in the usual body-centered model of the world.  This breakdown may be due to reduced sensory input or to a diminishment of proprioceptive feedback under conditions of reduced bodily movement.  This secondary model of the world is often constructed from a “bird’s eye view,” suggesting to the person that he or she is located in the air above the physical body.  Blackmore contends that such a bird’s eye view is frequently adopted when remembering a scene from one’s past and is thus a characteristic of mental models of the world constructed on the basis of memory.  While it is true that in her own research she found that OBErs (that is, people who claim to have had an OBE) were no more likely than non–OBErs to recall scenes from an overhead vantage point, she did find that OBErs were able to switch viewpoints in such imagined scenes more easily than were non–OBErs.  Blackmore further conjectures that if a dreaming person becomes aware that he is sleeping, he may construct a model of himself lying in bed and thus come to see himself as located outside of his body.  In her view, this might explain why the reporting of OBEs tends to go hand-in-hand with the reporting of lucid dreams (a term used to denote dreams in which one becomes aware that one is dreaming).

Thomas Metzinger cites Blackmore’s research indicating that OBErs have better ability to control and terminate dream content and have more flying dreams than do persons not reporting OBEs (Blackmore, 1986a) as evidence that OBEs are “just an additionally constrained set of lucid dreams” (Metzinger, 2005, p. 69).

Murray and Fox (2004) report evidence that persons reporting OBEs have body images that differ from those of persons not reporting OBEs.  Among several other measures examined, they found that OBErs had higher levels of somataform dissociation (psychological dissociation from one’s body), reduced self-confidence and reduced confidence in self-presentation.  These findings lend support to the psychological theories of OBE proposed by Palmer, Blackmore, Irwin and others.

Devinsky, Feldmann, Burrowes and Bromfield (1989) propose that the purpose of OBEs is to help potential prey organisms to feign death and to calm and clarify the mind in crisis situations.

Blanke and his coworkers have linked the generation of OBEs to a site in the right angular gyrus of the brain (Blanke, Ortigue, Landis, & Seek, 2002; Blanke, Landis, Spinelli & Seeck, 2004).  However, Neppe (2003) disputes this claim that an OBE-generating site exists in the right angular gyrus, pointing out that Blanke et. al’s findings are based on a single subject who had temporal lobe epilepsy with a site near the purported OBE center.  Neppe further observes that this subject’s OBEs were brief and atypical.  Neppe also points out that the existence of such a brain site does not rule out the possibility that OBEs involve paranormal processes.

A somewhat more outlandish theory to explain the OBE has been proposed by Munro and Persinger (1992).  They suggest that OBEs may be produced when the left hemisphere of the brain gains a glimpse of the independent workings of the right hemisphere.  This may lead the left hemisphere to perceive itself as separate from the rest of the body.  They cite an observed correlation between such a sense of detachment and mismatches in the electrical activity of the two cerebral hemispheres as evidence in support of this theory.

Research Findings Relating to the OBE

Incidence rates. A great many surveys have been conducted to determine how frequently people in the general population report OBEs (e.g., Hart, 1954; Green, 1967; Blackmore, 1978, 1982b, 1982c, 1984a; Palmer, 1979; Myers, Austrin, Grisso & Nickeson,1983; Irwin 1980; Tart, 1971).  The estimates of the incidence rate vary widely, from a low of 8 percent reported by Haraldsson et al. (1977) to a high of 54 percent reported by Kohr (1980).  Most surveys, however, indicate that somewhere between 10 percent and 20 percent of the general population report having had an OBE at some time in the past.  

Blackmore (1984a) found that 85 percent of the people who reported any OBE said that they had experienced out-of-body travel on more than one occasion.  She also found that 85 percent experienced some sort of strange sensation before entering the OBE state.  These sensations included vivid imagery, disorientation, shaking and vibrations, and the seeing of tunnels and doorways.   

Carlos Alvarado (1984) asked college students reporting OBEs whether they experienced themselves as being housed in any sort of second body during the OBE.  Thirty-five percent said they experienced themselves as not having any sort of body, 23 percent experienced themselves as located in a second body similar to the physical body, 13 percent experienced themselves as a cloud, mist, ball of light or point in space, 8 percent had no recollection, and 20 percent reported some other form of existence.  Alvarado found that 81 percent of the students who reported having an OBE claimed to have had more than one OBE, a figure similar to Blackmore’s.

All of the above-mentioned surveys were conducted with modern, Western populations. This raises the question of whether the OBE is a universal experience or is peculiar to Western culture. To address this issue, Dean Shiels (1978) conducted a study of 70 nonwestern cultures. He found belief in some form of out-of-body travel in 95 percent of these cultures. Sometimes these beliefs do not correspond to the classical OBE as described above, but may encompass such doctrines as the travel of the soul to nonphysical realms during dreams.

Psychological factors. A large number of studies have been conducted to see if there is any relation between the reporting of OBEs and mental imagery ability (e.g., Palmer & Vassar, 1974; Irwin, 1979, 1980, 1986; Cook & Irwin, 1983; Blackmore, 1982c, 1983c, 1986b).  Such a positive relationship might be taken as support for the idea that the OBE is largely a fantasy experience. The net result of these studies is that there is little evidence for a relationship between the reporting of OBEs and the experienced vividness of mental images, a person’s ability to control her mental imagery, or the tendency to adopt any particular perspective when recalling or imaging a visual scene.  There is, however, a fairly consistent body of evidence indicating that OBErs have a greater ability to switch perspectives when viewing imagined scenes than do persons not reporting OBEs (Cook & Irwin,1983; Blackmore, 1983c, 1986b).  There is also a fairly consistent body of evidence indicating that persons who report OBEs tend to fit the profile of a “fantasy-prone” personality. (Irwin 1980, 1981; Myers, Austrin, Grisson & Nickeson, 1983; Wilson & Barber, 1982; Stanford, 1987; but see also Gabbard, Jones & Twemlow,1980).  This would lend some support to the view that OBEs may simply be the product of an overactive imagination.

One fairly consistent finding is that OBErs tend to report having lucid dreams more often than do non–OBErs (Blackmore, 1982b, 1982c, 1983a, 1984a, 1986a, 1986b; Irwin, 1986; Stanford, 1990b).  Rex Stanford (1990b) has interpreted this to mean that people tend to confuse OBEs with lucid dreams.  (Lucid dreams, it will be recalled, are dreams in which the dreamer is aware of the fact that he or she is dreaming.)  Another possibility is suggested by the fact that some people have reported that they are able to deliberately launch OBEs from the lucid dream state.  One such person was the late D. Scott Rogo.  Rogo trained himself to control his hypnagogic imagery (the imagery one has when first falling asleep) in order to enter a state of lucid dreaming.  While in the lucid dream state, Rogo like many other lucid dreamers was able to manipulate his dream imagery. He used this ability to “order up” a car, which he then drove and crashed, producing an OBE.  Perhaps other lucid dreamers have learned similar techniques (Mitchell, 1981).

Experimental Studies of the OBE

There have been several attempts to determine whether people can identify target items placed at a location to which they have allegedly projected during an OBE.  Of necessity, these experiments have focused on deliberately produced OBEs, sometimes using special subjects who claim to be able to enter an OBE at will and sometimes using ordinary people as subjects.  In the latter case, the subjects typically undergo some sort of training procedure that supposedly will allow them to experience an OBE in the experimental situation.  Such induction techniques usually involve the subject entering a state of relaxation, possibly through the use of auditory tapes.  Occasionally visual input is restricted by placing ping-pong balls over the subject’s eyes, producing a “ganzfeld,” or blank field of homogeneous visual stimulation.  John Palmer and his colleagues used such techniques in an attempt to induce OBEs in a group of ordinary citizens, who were then asked to travel to another room in the OBE state and to identify an ESP target placed there.  While 45 percent of the subjects claimed to experience literal separation from their bodies, they were not successful in identifying the target (Palmer & Vassar, 1974).  A second experiment was a little more successful, with the subjects reporting OBEs having greater success in identifying the target than subjects not reporting OBEs (Palmer & Lieberman, 1975).  In a similar experiment, Smith and Irwin (1981) found a positive relationship between degree of experienced out-of-body separation and success in identifying a target.  One problem with their experiment is that the same materials, a small sheep skull and potted palm, served as targets for all the subjects. Thus, their results could be due to a tendency for people who claim to experience OBEs to also report death-related or plantlike imagery.

Several studies have been made of special subjects who claim to be able to produce OBEs at will.  One of the most famous of these is Charles Tart’s study of the subject he refers to as Miss Z (Tart,1968).  In the one reported trial with Miss Z, she was asked to identify a five digit number that had been placed on a shelf above her while she lay on a cot with EEG electrodes affixed to her scalp. She was able to identify all five digits successfully, a feat which would occur by chance only one time in one hundred thousand.  Unfortunately, no one was in the room observing her at the time.  Tart conceded that it might be possible that Miss Z could have seen a reflection of the number in a clock that was present in the experimental chamber. Susan Blackmore (1982c) has pointed out that Tart placed the number on the shelf when Miss Z was already in the room, so that it is possible that she was able to get a glimpse of it then.  Thus, this experiment was far from perfect.  Unfortunately, Miss Z moved away from Tart’s area and was not available for further testing (although one might have thought that, given her level of success, Tart would have moved his lab to her new location!). Tart (1967, 1969) attempted a similar experiment with Robert Monroe, a well-known OBEr who has written several books on the subject, but without success.

Janet Mitchell (1981) conducted a very similar experiment with another prominent OBEr, the artist Ingo Swann.  Swann did have some success identifying the target materials, but once again he was allowed to be in the room with the target materials with no one observing him.  While his movements were restricted by the EEG electrodes attached to his head, it is conceivable that he could have used a device such as an extensible mirror to identify the targets, which were placed on a platform near the ceiling of the room.

Osis and McCormick (1980) conducted an experiment in which the special subject Alex Tanous attempted to identify a target displayed in an “Optical Image Device” (OID) while in the OBE state.  Although Tanous had little overall success in identifying the target, a strain gauge placed in the vicinity of the OID showed greater activity when Tanous correctly identified the target than when he did not.

There have been several other attempts to detect some sort of physical effect at the site to which a person has allegedly projected during an OBE, using both animate observers and physical instruments as detection devices. Such physical effects could be interpreted as signs of an astral body.  Perhaps the most elaborate such attempt was conducted with the special subject Keith Harary at the Psychical Research Foundation in Durham, North Carolina (Morris, 1974; Morris, Harary, Janis, Hartwell & Roll, 1978).  In this study, Harary attempted to project himself from the experimental room to an adjacent building during a voluntarily produced OBE.  He was unable to identify target materials placed in the second building.  No behavioral changes were observed in a snake or small rodents located in the second building during Harary’s projection, although a kitten was less active and cried less during Harary’s OBE than during control time periods. 

This effect was not, however, obtained in two follow-up studies.  No consistent responses from human detectors were observed, although one witness claimed to have seen Harary on a video monitor during one of his projections.  Several instruments were used to measure physical effects in the area to which Harary had projected.  These included devices to measure several electromagnetic effects and a delicate thermistor to measure temperature changes.  No physical effects related to Harary’s OBEs were observed with these devices.

There have been many attempts to detect the astral body by weighing or photographing the soul as it leaves the physical body upon death or by photographing the human aura, which is sometimes identified with the astral body. Because these attempts have not been performed with the subject explicitly in an OBE state, they will be discussed later in this chapter, in the context of the physical detection of “ghosts” and other manifestations of alleged discarnate spirits.  


Most people are unable to identify target materials while claiming to be located in the vicinity of those target materials during an OBE.  In fact, the overall results from these types of OBE experiments are in general no more impressive than the fairly weak effects obtained in ESP experiments, and thus it is plausible that even these minimal successes are due to simple ESP.  This failure to reliably identify target material during OBEs constitutes fairly strong evidence against the view that some aspect of the person has literally projected from the body and is perceiving the remote location. This body of evidence would thus support the view that OBEs are simply the product of fantasy or hallucination.

Near-Death Experiences

Some people who have come close to dying, such as in cases of cardiac arrest or being knocked unconscious during an automobile accident, but who have been revived after a period of apparent unconsciousness, report an encounter with an apparently nonphysical or postmortem realm.

Such experiences are called “near-death experiences” (NDEs) and were brought to the attention of the general public through the publication in 1975 of Raymond Moody’s best-selling book Life after Life (Moody, 1975).  Moody lists the following characteristics of the NDE: 


 Loud ringing or buzzing noises, 

 Sensations of traveling down a tunnel-like passage, 

 Out-of-body experiences, 

 Viewing the physical body from an external vantage point, 

 Emotional upheavals, 

 Sensations that one possesses a quasi-physical astral body,

 Encounters with the apparitions of deceased relatives and friends, 

 An encounter with a “being of light,” who serves as a spiritual guide (frequently interpreted as a Christ-like being in the West), 

 Undergoing an evaluation of one’s life, 

 Experiencing a panoramic review of one’s life, 

 Approaching a barrier or border, 

 Being told that one must go back (that is, return to one’s physical body and rejoin the realm of the living), 

 Not wishing to return, 

 Experiencing deep feelings of joy and peace, 

 Experiencing a reunion with the physical body, and 

 Having experiences of an ineffable nature (e.g., sensations of color or mystical union that cannot be described in words.)


Of the fifteen elements listed above, Moody notes that usually eight or more are reported by a typical NDEr, although no single case in his collection included more than 12 of the above 15 characteristics. He further notes that no single item of the 15 is included in every single NDE account.

Cook, Greyson, and Stevenson (1998) cite the following case from the May 26, 1935 (London) Sunday Express, which contains everything one could ask for in a spontaneous case of psi.  Not only does it involve an NDE, but also multiple incidents of crisis psi as well as an attempted reincarnation.  

In 1911, at the age of sixteen, I was staying about twelve miles from my own home when a high wall was blown down by a sudden gust of wind as I was passing.

A huge coping stone hit me on top of the head.

It then seemed as if I could see myself lying on the ground, huddled up, with one corner of the stone resting on my head and quite a number of people rushing toward me.

I watched one of them move the stone and some one took off his coat and put it under my head, and I heard all their comments: “Fetch a doctor.”  “His neck is broken.”  “Skull smashed like an eggshell.”

He [apparently a doctor] then wanted to know if anyone knew where I lived, and on being told that I was lodging just around the corner he instructed them to carry me there.

Now all this time it appeared as though I was disembodied from the form lying on the ground and suspended in mid-air in the center of the group, and could hear everything that was said.

As they started to carry me it was remarked that it would come as a blow to my people, and I was immediately aware of a desire to be with my mother.

Instantly I was at home, and father and mother were just sitting down to their midday meal.  On my entrance mother sat bolt upright in her chair and said, “Bert something has happened to our boy.”

“Nonsense,” he said, “whatever has put such an idea in your head?”

There followed an argument, but mother refused to be pacified, and said that if she caught the 2 p.m. train she could be with me before three and satisfy herself.

She had hardly left the room when there came a knock on the front door.  It was a porter from the railway station with a telegram saying that I was badly hurt.

Then suddenly I was again transported - this time it seemed to be against my wish - to a bed-room, where a woman whom I recognized was in bed, and two other women were quietly bustling around, and a doctor was leaning over the bed.

Then the doctor has a baby in his hands.

As once I became aware of an almost irresistible impulse to press my face through the back of the baby’s head so that my face would come into the same place as the child’s.

The doctor said, “It looks as though we have lost them both.”  And again I felt the urge to take the baby’s place in order to show him we was wrong, but the thought of my mother crying turned my thoughts in her direction, when straightaway I was in a railroad carriage with both her and father.

He [Mr. Martin’s father] was looking at his watch, and she [Mr. Martin’s mother] was saying that the train was right on time.

I was still with them when they arrived at my lodgings and were shown into my room where I had been put to bed.

Mother sat beside the bed and I longed to comfort her, and the realization came that I ought to do the same things as I felt impelled to do in the case of the baby and climbed into the body in the bed.

At last I succeeded, and the effort caused me to sit up in bed fully conscious.  Mother made me lie down again, but said I was alright, and remarked that if was odd she knew something was wrong before the porter had brought the telegram.

Both she and dad were amazed were amazed at my knowledge.  Their astonishment further increased when I repeated almost word for word some of the conversation they had at home and in the train.

Mother remarked that she supposed that when some people came close to death they were gifted with second sight.

I replied by saying that I has also been close to birth as well, and told then that Mrs. Wilson, who lived close to us at home, had a baby that day, but it was dead because I could not get into its body.

We subsequently learned that Mrs. Wilson died on the same day at 2:05, delivering a stillborn girl.

I am convinced that if I had willed myself into that baby’s body, today I would be a Miss Wilson, instead of being - W. Martin, 107 Grove Streed, Liverpool.   [Quotation taken from Cook, Greyson and Stevenson (1998, pp. 387- 388).]

Several surveys relating to NDEs have been carried out (e.g., Sabom, 1982; Pasricha, 1993, 1995; Ring, 1980; Long, 2003; Britton & Bootzin, 2004).  The data indicate that somewhere around one half of the people who have been revived from a state of clinical death claim to have experienced an NDE, a remarkably high figure (see Sabom, 1982; Pasricha, 1993, 1995; and Ring, 1980); although Barŭšs (2003) reports an incidence rate of 9% to 18%

Kenneth Ring (1979, 1980) conducted a study of 102 persons who had experienced NDEs in order to determine how frequently various elements of the NDE, as described by Moody, occurred. He found that 60 percent of his respondents reported feelings of peace and contentment during their NDEs, 33 percent reported an out-of-body experience, 23 percent reported sensations of entering a region of darkness or traveling down a tunnel, 20 percent sensed a (typically benevolent) presence who aided them in reviewing and evaluating their lives, 17 percent reported seeing a light to which they were drawn, and 10 percent experienced seeing a world of “preternatural beauty.”

The skeptical view of NDEs is of course that they simply represent hallucinations, dreams and fantasies constructed by the mind under conditions of physical trauma or stress. Various neurophysiological causes for such hallucinations have been proposed, including seizures in the temporal lobes of the brain, (e.g., Thorton, 1984; Wilson, 1928; Carr, 1982; Persinger, 1983), lack of oxygen to the brain (e.g., Rodin,1980; Schnaper, 1986), the release of endorphins in the brain (e.g., Shaver, 1986; Blackmore, 1993), and the random firing of cells in the visual cortex of the brain (e.g., Blackmore 1991b, 1992; Siegel, 1980).   Ronald Siegel (1977) has also noted that tunnel-like imagery is one of the eight common “form constants” of hallucinations induced by LSD.

Britton and Bootzin (2004) found that persons reporting NDEs are characterized by elevated temporal lobe epileptiform EEG activity relative to control subjects and also report significantly more temporal lobe epileptic syndromes.  The elevated epileptiform activity is almost completely lateralized to the left hemisphere in such subjects.  Britton and Bootzin found that NDEs were not associated with dysfunctional stress reactions, such as dissociation, post-traumatic stress disorders and substance abuse.  Instead, they found NDEs to be associated with positive coping styles. 

 Theories attributing the out-of-body component of the NDE to states of depersonalization, a denial of death, and a reliving of the birth trauma were discussed in the previous section.

As with the other categories of evidence for survival of the personality of death to be discussed below, the primary evidence that NDEs are not simply fantasies or hallucinations is provided by cases in which patients become anomalously aware of information during an NDE when they apparently had no normal means of acquiring such information.  In many cases, this information pertains to events at the scene of an accident or during a surgical procedure that the patient witnesses from a vantage point above the body, while the body itself is apparently unconscious.  For instance, a patient undergoing cardiac arrest may describe events occurring during the resuscitation procedure. If the procedure itself is simply described, it is possible that the patient is merely demonstrating knowledge of resuscitation procedures she has gleaned from watching television shows, etc.  If specific idiosyncratic events in the vicinity of the patient’s body are described, it is quite possible that the patient, despite her apparent unconsciousness, retained enough awareness and sensory ability to perceive the described events.  Indeed, there is a wide body of evidence that patients retain some sensory capacity even under conditions of deep surgical anesthesia (e.g., Bennett, Davis & Giannini, 1985; Goldmann, Shah & Hebden, 1987; Evans & Richardson, 1988; Furlong, 1990; Pearson, 1961; Kihlstrom, Schachter, Cork, Hurt & Behr, 1990; Millar & Watkinson,1983).

It is less easy to explain cases in which the patient reports awareness of events occurring at locations remote from the body during the NDE, such as the case of the woman who saw a tennis shoe on a window ledge in the hospital during an NDE, which was discussed in the previous section. Such cases are exceedingly rare, however. There are some data indicating that NDErs tend to have fantasy-prone personalities (see for instance Twemlow & Gabbard, 1984; and Council, Greyson & Huff, 1986), which would give further support to the theory that NDEs simply represent fantasies and hallucinations.   

Deathbed Visions

Closely related to the near-death experience is the phenomenon of deathbed visions, in which dying patients apparently see apparitions of deceased relatives and friends, who appear at their bedside for the seeming purpose of conducting the dying person into the afterlife.  In fact, out-of-body experiences and deathbed visions could conceivably be regarded as unusual NDEs in which only one component of the NDE occurs.  One feature that distinguishes deathbed visions from typical NDEs is that the patient is not generally in a state of unconsciousness or “clinical death” at the time of the experience.  Deathbed visions have been studied by William Barrett in the 1920s and the team of Karlis Osis and Erlendur Haraldsson in the 1960s and 1970s (Barrett, 1926; Osis (1961; Osis & Haraldsson,1977a, 1977b).  Osis and Haraldsson collected their data from surveys of doctors and nurses in the United States and India regarding their recollections of any visions reported by dying patients.  In the United States, hallucinated figures were primarily of deceased persons (70 percent), the rest being split between living persons (17 percent) and religious figures (13 percent). In India, a much higher percentage of religious figures was reported (50 percent), with deceased persons representing only 29 percent of the hallucinations, and living persons 21 percent.  In approximately three-fourths of the cases in both countries, the purpose for the apparitional figure’s appearance was interpreted to be to escort the dying person into the afterlife.  In both countries, the percentage of patients reporting such apparitions declined as the clarity of consciousness, as measured by the drugs administered and the presence of fever, declined.  Osis and Haraldsson take this as evidence that such apparitions do not represent mere hallucinations engendered by psychopathological states; on the other hand, it could equally well be argued that persons in an impaired state of consciousness may be less able to communicate coherently about such an apparitional experience.

One type of deathbed vision case that is a little more difficult to attribute to a simple hallucinatory process occurs when a deceased person appears to a dying patient who had no knowledge that the appearing person had died.  Karlis Osis quotes the following case from William Barrett’s investigations:

On Jan. 12, 1924, a Mrs. B. was dying in a hospital in England. Her sister Vida had died on Dec. 25, 1923, but her illness and death had been carefully kept from Mrs. B because of her own serious illness. As Mrs. B. was sinking, she said: ‘It is all so dark, I cannot see.’ A moment later her face brightened and she exclaimed: ‘Oh it is lovely and bright; you cannot see as I can.’ A little later she said: ‘I can see father, he wants me, he is so lonely.’ then with a rather puzzled expression: ‘He has Vida with him,’ turning to her mother—‘Vida is with him!’ A few moments later she died.  (Osis, 1961, p. 16.)

On the other hand, Michael Grosso (1981) has noted that such “Peak in Darien” cases (as they are called) are extremely rare.

Stevenson (1995) describes a case that is very unusual in that a second witness perceived the deathbed visitor.  This case involved a girl whose grandfather, who was dying of leukemia, was living with her family.  She reports:

Granddaddy called to me to give him a drink of water.  I failed in my attempts to lift him enough to wet his lips.  The disease had reduced his once tall, strong stature to [that of] a frail, weak invalid.  I called mom at work to ask for help, but she told me it would have to wait until dad…returned from work at noon.

Shortly thereafter I heard granddaddy calling out to his wife Hazel.  Grandmom had died nine years prior, …so I thought he must be losing his mind.  I ran down the hall to make another attempt to help him.  I was amazed to find him sitting up, smiling with his arms reaching out.  The room was filled with a warm, bright light.  He spoke to grandmom, who was standing at the foot of the bed.  Neither of them acknowledged my presence.  She was there for a brief moment, and when granddaddy laid back down, his soul escaped with her.  He died with a smile of his face.  (Stevenson, 1995, p. 360.)


Occasionally, deceased persons appear in dreams. Usually, of course, such figures can be dismissed as images constructed by the dreamer’s subconscious mind (or spontaneously firing neurons).  On rare occasions, however, such deceased persons may communicate information to the dreamer that neither the dreamer nor any other living person had any apparent normal means of knowing.  In one famous and oft-cited case, known as the Chaffin will case (described in Myers, 1903), a father communicated the existence of an alternative will to one of his sons in a dream.  Under the original will, one of the dreamer’s brothers had inherited the father’s farm and the rest of the family had inherited nothing. Based on information given to him in his dream, the son was able to locate a second will in his father’s handwriting, in which the property was distributed more equally.  This will was admitted to probate.  A cynic could dismiss this case as fraud combined with forgery, especially as the dreamer had much to gain by perpetrating such a fraud.  In fact, Ian Wilson (1987) has noted that most of the witnesses in the Chaffin will case were family members who stood to profit from the new will.  Less cynically, one might assume that the dreamer learned of the will’s existence and location through clairvoyance or that he had picked up cues as to the will’s existence from his father’s behavior before death.

George Zorab (1962) has compiled a collection of cases of the “Chaffin will type.” In one such case, a bookkeeper in Holland had been accused of embezzling approximately 1,800 guilders and died before his name could be cleared.  After the bookkeeper’s death, his son had a dream in which a white figure appeared to him and said, “Look in the ledger at the dates.”  Upon checking, it was found that his father had included the date at the top of a column in one of his additions.  It is quite possible that the son may have unconsciously noted the identity between the disputed amount and the date and that this fact entered his conscious awareness in the form of the dream in question.  There are many examples on record of such problem-solving activity in dreams, a notable one being Elias Howe’s invention of the sewing machine, which was based in part on a dream Howe had in which a group of cannibals were about to eat him. In this dream some of the cannibals thrust spears at Howe.  These spears had holes in them near their tips, which suggested to Howe that he should put the hole near the point of the needle in his sewing machine rather than at the base of the needle.  Another example of such problem-solving activity in dreams is provided by August Kekule’s discovery of the ringlike structure of the benzene molecule, which was presented to him in the form of a dream in which benzene molecules were transformed into a group of dancing snakes that suddenly took their tails into their own mouths.

Because of the existence of such counterexplanations as those discussed above, the existing evidence from dreams cannot be taken as definitive evidence of the survival of the human personality of death.


Another category of spontaneous psi experiences that are often taken as evidence for the survival of human personality of death consists of apparitional experiences. The sighting of apparitions or “ghosts” is not as uncommon as one might think. In John Palmer’s mail survey of the greater Charlottesville, Virginia, area, 17 percent of the respondents reported having seen an apparition (Palmer, 1979).  A Gallup poll indicated that about 9 percent of the population of Britain believe that they have seen a ghost (Gallup,1982).  

The following case, taken from Wright (1999) involves an auditory crisis “apparition.”

I was always very close to my grandfather.  He had a wonderful sense of humor and he always related to me as though I were a little kid.  And he’d tease me.  He’d say very affectionately in this real deep voice, “ Mary-Minn, you’re a baddie, a real baddie.”  He said that from the time I was about four or five and he still said it when I was in my twenties.  Well, he went into a coma for a week or two. I wasn’t talking to most people in my family - we had had some horrible feud.  But I’d been keeping up with my grandmother and I knew he was in a coma and would probably die, so I was sitting in the office one rainy afternoon, typing up a disbursement voucher, and suddenly this deep voice came out and said, “Mary-Minn, you’re a baddie, a real baddie.”  And that was it.  I knew it was him and I knew that nobody else heard it.  I mean I knew that he had died, he had just expired.  Well, the phone rang about two minutes later and he had.  (Wright, 1999, p. 262.) 

Of course, a determined skeptic could attribute this case to the fact that the grandfather’s death was not unexpected, which may have triggered auditory memories sufficiently vivid to be classed as hallucinatory.   

A more classic, visual ghost experience is reported by Stevenson (1995):

[O]n the morning of May 29, 1975, E. W. [the percipient in Stevenson’s case] went to the outside door of her house (which faces the main road) in order to bring inside the delivered bottles of milk that had been left on her doorstep.  She later thought she had done this between 10:00 and 10:30 a.m.  She looked across the road and saw her neighbor Ronald McKay walking out of the driveway of his house and then along the road or drive as if going to the nearby factory of which he was the manager.  E. W. and her husband had known that the McKays had been away on vacation and believed that they were still away.  When E. W. went back inside her house, she said casually to her husband: “I see the McKays are back.”  Her husband asked her when they had come back.  E. W. replied: “I don’t know, but I saw Ron go down the drive.”  About a half hour or perhaps an hour later, a senior employee of Ronald McKay’s factory came to the house and spoke with E. W.’s husband.  He then asked her when she had seen Ron McKay, and she repeated what she had said earlier.  Her husband then said that the factory employee had information that Ronald KcKay had died that morning while on vacation in Enlgand about 150 miles away from Dunfermline.  (Stevenson, 1995, p. 358).

Stevenson estimates that the time interval between E. W.’s apparitional experience and McKay’s death could not have been more than 3-4 hours.  He also estimates that she watched the apparition for at least ten seconds from a distance of 50 feet, reducing the chances of misidentification.  

Stevenson cites several survey sources indicating that somewhere between 10% and 27% of the general population have had apparitional experiences. 

Erlendur Haraldsson (1981) conducted a detailed survey relating to apparitional experiences in Iceland.  Of the 902 respondents in Haraldsson’s survey, 31% affirmed having experienced the presence of a deceased person. Detailed interviews with 100 of the respondents who reported such experiences indicated that 16% of the experiences involved the mere feeling of the deceased person’s presence, 70% involved a visual hallucination, 24% included an auditory experience, 7% a tactile experience, and 5% an olfactory sensation.  One-third of the cases occurred when the percipient was falling asleep, which indicated to Haraldsson that hypnagogic imagery was frequently involved in the experience. In 23% of the cases the appearing person had died violently, which Haraldsson notes is a disproportionately high number.  In 43% of the cases, more than one person was present at the time of the apparition, and in one-third of these cases it was claimed that the apparition was collectively perceived.

A survey modeled after the early “Census of Hallucinations” conducted by the British Society for Psychical Research (Sidgwick et al., 1894) has been reported by D. J. West (1990).  As in the original census, volunteers interviewed their acquaintances regarding apparitional experiences. Of 1,129 distributed questionnaires, 840 were returned, with 14.6% of the respondents reporting an experience with hallucination of a human figure. Discounting dubious cases, West concludes that 11.3% of the respondents reported “genuine” hallucinations, which he notes compares favorably to the figure of 10% obtained by the early Society for Psychical Research.  Only 9 of the 840 respondents reported detailed, apparently psi-related hallucinations, a figure that is also comparable to the proportion obtained in the earlier survey.

It is very common for people to experience the presence of a deceased spouse.  A study in Wales indicated that 43% of widows and widowers had seen an apparition of their dead spouses (Rees, 1971), and a second survey indicated that nearly 60% percent of the widows in the greater Los Angeles area had experienced the presence of their deceased spouse (Kalish and Reynolds, 1974).  Of course, the fact that a bereaved widow has a vision of her deceased husband does not imply that she has accurately perceived the presence of her husband’s now disembodied spirit. The vision could simply be a grief-induced hallucination.

Occasionally, however, such postmortem apparitions transmit information to the percipient which the percipient had no apparent normal means of knowing. In the case of crisis apparitions, the information transmitted is usually simply that the appearing person has died or been injured.  As we have previously remarked, such apparitions could be simply ESP-induced hallucinations, and therefore they cannot be taken as providing definitive evidence that the spirit of the appearing person has survived death.

On the other hand, not all cases involving information transmission fit into the crisis apparition category. For instance, Stanislav Grof (1990) describes two cases in which participants in LSD sessions apparently received accurate information from the dead.  The first case involved an LSD session in America, in which the participant “saw” a deceased person who gave him the name and address of his parents in Moravia.  When the parents were contacted at the address in Moravia, they stated that they had a son who had died three weeks prior to the LSD session.

In Grof’s second case, the wife of Grof’s colleague Walter Pahnke, who had died in a scuba diving accident, experienced an LSD-induced vision of her deceased husband. The apparition requested her to return a borrowed book located in the attic of her house. She claimed to have had no prior knowledge of the book or its location, but she was able to find it and return it.

Of course, neither of these cases constitute definitive evidence of survival. In fact, both could be due to cryptomnesia, or hidden memory.  Possibly the first percipient may have read an obituary notice for the dead Moravian youth, but had forgotten that he had read it.  Similarly, Mrs. Pahnke may have had a subconscious memory of the borrowed book.  Counterexplanations in terms of ESP are also possible.  

One apparitional experience that is frequently cited as providing evidence of survival is that of the “Red Scratch” case, reported in Myers (1903). The percipient in this case was a traveling salesman, who was staying in a hotel room.  At one point he looked up from recording his orders and saw an apparition of his sister, who had died nine years previously, sitting beside him at the table.  As he addressed her and moved toward her, she disappeared.  Later, telling his parents about the apparition, he mentioned a red scratch that he had seen on the side of the girl’s face.  At that point his mother nearly fainted, then arose trembling and stated her belief in the survival of her daughter’s spirit, as she had in fact made such a scratch on her daughter’s face at her funeral while attending to the body.  She covered up the scratch with makeup and had told no one about it. It is, however, easily imaginable that the makeup job was not perfect and that the son may have noticed the scratch at the time of the funeral.  Alternatively, he may have subconsciously overheard his mother talking in her sleep about the incident soon after the funeral (or, possibly, derived the information telepathically from her).  Once again, this case does not provide conclusive evidence of survival.


Haunting cases involve repeated anomalous events, usually associated with a particular location or object.  Very often, apparitions or “ghosts” are sighted.  Sometimes several witnesses will claim to have seen apparitions at the location over a period of time.  Some of the apparitions may be collectively perceived.  Occasionally anomalous sounds are heard, including raps, footsteps and voices.  Sensations of cold and strange odors are sometimes reported. Occasionally, anomalous movements of objects are associated with hauntings, although cases in which this feature is prominent are usually classified as poltergeist cases.  As mentioned in Chapter 3, Gauld and Cornell (1979) found hauntings and poltergeist cases to constitute two fairly distinctive “clusters” of phenomena in their statistical analysis of such cases.  Among their findings, they found that cases involving apparitions were more likely to involve the rattling and opening/shutting of windows and doors as well as experiences of unseen but felt hands. 

Hauntings have been recorded throughout the ages.  The Roman writer Pliny the Younger, for instance, reported a haunting case in the first century A.D.

Certain types of haunting phenomena may be due to the effects of suggestion and to the misattribution of normal sounds to paranormal causes.  A frightened person alone in a house with a reputation for being haunted may misinterpret a normal settling noise as a paranormal rap or a ghostly footstep. The resulting shivers of fear may be responsible for sensations of cold.

The repeated sighting of apparitions by multiple witnesses is of course less easy to explain as the misinterpretation of normal stimuli or as due to psychopathology on the part of the percipient.  There is thus a greater temptation in such cases to attribute the recurring vision to the surviving spirit of a deceased person.

Let us examine a fairly typical haunting case that was investigated by Teresa Cameron and William Roll (Cameron & Roll, 1983). This case involved repeated sightings of an apparition of a male figure, who was usually described as about six feet tall, weighing 190 pounds, and typically wearing a brown suit, in a radio station in Virginia over a time period from October of 1980 through April of 1981.  The figure was usually seen in a standing position, and the sightings occurred in a hallway near the women’s restroom or in the doors leading off the hallway.  Five employees witnessed the apparition.  Three of the employees had heard stories about ghosts in the station, but had treated these stories in a joking manner.  Evidently, a former employee had reported many sightings of apparitions, both inside and outside the building.  This employee reportedly had severe psychological problems and left her employment under strained circumstances.  She did not respond to Cameron and Roll’s inquiries or grant an interview.

The first sighting during the time period in question was by William Morrison, an engineer and carpenter.  After an initial fleeting glance, Morrison saw a male figure wearing a brown suit from a distance of about twenty feet. He said the figure appeared to take a few steps while he was looking at it, although he did not recall seeing any legs or feet.

Carolyn McDougall, a 30-year-old continuity director at the station, heard papers “riffling” as she came out of the ladies’ room.  She then saw a male figure wearing a brown jacket standing in a doorway. She stated that she saw only “down to the start of his pants.”  She did not recall seeing any face, legs or feet on the figure.  Although her experience occurred a day or two after Morrison’s sighting, she did not hear of Morrison’s experience until after her own vision. Both of these sightings occurred in October of 1980.

In April of 1981, Gloria Johnson, a receptionist at the station, was coming out of the ladies’ room when she saw a transparent male figure wearing a dark suit moving (but neither walking nor “gliding”) down the hallway.  She had heard nothing about prior sightings at the station before she had her experience, and she had begun her employment in December of 1980.

A 30-year-old engineer named Henry Eaton saw a strange male seated at a fellow employee’s desk.  He turned to reach for his own chair in order to sit down, and by the time he redirected his attention to the unknown figure it had vanished.  This sighting occurred on the same day as the vision of Gloria Johnson, but he did not mention it until Miss Johnson burst into the room to describe her own sighting. He had previously heard stories about ghosts in the building.

Jack Sneider, a 21-year-old announcer on the evening shift, twice saw a strange male figure when no one else was presumably in the building, these sightings taking place in November and December of 1980.

Cameron and Roll had the witnesses take Wilson and Barber’s Inventory of Childhood Memories and Imaginings (ICMI).  Based on these scores and interview data, Cameron and Roll conclude that three of the witnesses may have been psychologically predisposed to having apparitional experiences.  Carolyn McDougall obtained a very high score on the ICMI, indicative of a fantasy-prone personality. She is also a self-described psychic who has had other apparitional experiences and has reported seeing UFOs.  Gloria Johnson had previously seen an apparition of her grandfather and had experienced a recurrent apparition in her childhood.  Henry Eaton obtained a high score on the ICMI and has been diagnosed as manic-depressive.  Thus, these three witnesses may have had various forms of psychopathology, or at least fantasy-prone personalities, that may have rendered them prone to having apparitional experiences.

Cameron and Roll note that Eaton and Morrison both had visual problems and that Morrison and Sneider saw the visions at night and in poorly lit areas.  Morrison also reported feeling quite fatigued on the night of his sighting.  Having previously heard stories of ghosts in the station, these witnesses might have been primed to interpret ambiguous stimuli experienced under poor observational conditions as ghostly phenomena.  (While Sneider had reportedly not heard such stories prior to his experiences, these stories may have colored his retrospective interpretation of ambiguous events.)

One piece of evidence supporting the paranormality hypothesis, Cameron and Roll conclude, is the tight clustering in time of Morrison’s and McDougall’s experiences as well as of Johnson’s and Eaton’s experiences.  As to agency, McDougall and Morrison thought that the apparitions resembled Charles Michaux, a former employee of the station who had died in 1978.  Michaux had been fired under stressful conditions before Christmas of 1977, causing a fight to break out among the remaining employees during the annual Christmas party. Michaux died of a heart attack shortly thereafter.  Obviously, however, the evidence from this case, like the evidence from most hauntings, does not constitute a clear cut case for any type of paranormal process, much less the survival of a discarnate spirit.

Even animals can sometimes appear as ghosts. My next-door neighbor during my teenage years had the experience of repeatedly seeing a cocker spaniel lying on a particular step in her stairway or under a desk built into the wall.  When she mentioned this to the former owner of the house, he told her that at the time he lived in the house he had a pet cocker spaniel that used to like to sleep in precisely those locations.   

There have been a few attempts to study hauntings scientifically. One method, used by Michaeleen Maher and her coworkers (Maher & Schmeidler, (1975; Maher & Hansen, 1992a, 1992b, 1995; Roll, Maher & Brown, 1992), involves dividing up a house into many different zones.  A number of psychics, or “sensitives,” then state which zones they feel are associated with ghostly phenomena and attempt to describe any apparitions that might have been seen. A set of control subjects or skeptics then do the same.  While the results have been mixed, in some cases the psychics’ descriptions of the ghostly phenomena corresponded more closely to the witnesses’ accounts than did the skeptics’ descriptions.  This, however, proves nothing, as certain locations in the house may naturally suggest ghostly presences, thus accounting for the fact that both the psychics and the actual witnesses assumed that ghosts would be present at these locations.  Similarly, certain houses may suggest certain types of ghosts. Thus, correspondences between witnesses’ and outsiders’ descriptions of the location and nature of ghosts cannot be taken as proving anything about the paranormality of the phenomena.  Similarly, if the psychics were to provide descriptions that corresponded more closely to witnesses’ accounts than the control subjects or skeptics did, this would again prove nothing.  Psychics and people who see ghosts may merely tend to think alike.  Also, self-proclaimed sensitives who frequently investigate hauntings may have gathered a great deal of knowledge relating to where people will report seeing ghosts.

There have been a few attempts to detect physical anomalies at haunting locations, but these have generally failed to yield any sort of consistent effect. One intriguing finding was reported by Dean Radin and William Roll (1994).  They found the activity of a Geiger counter to be significantly increased when placed in an area of space said by a psychic to be currently occupied by a ghost, suggesting that this ghost may have been in some sense “radioactive.”  They speculate that the psychic may have been able to sense local regions of increased radioactivity, such as pockets of radon gas, or that she may have influenced the results by moving a radioactive piece of jewelry closer to the Geiger counter during the tests.  Two of the investigators also witnessed a luminous blob in a room that the psychic claimed was occupied by a ghost, further suggesting the existence of some sort of physical anomaly in the environment.

Maher and Hansen (1995) found curious artifacts in Polaroid and video recording tests performed at sites of reported haunting phenomena.

Tandy (2000) found elevated infrasound levels at a frequency of 18.9 Hz in a reputedly haunted 14th century cellar beneath a tourist Information Center in Coventry, England.  These infrasound waves were especially pronounced at sites where apparitions have been experienced.  Tandy and Lawrence (1998) had previously proposed that apparitions and sensations of a “presence” might be caused by 19 Hz standing waves.

Braithwaite, Perez-Aquino and Townsend (2004) found evidence of heightened magnetic activity in the area of a pillow in a haunted castle.  They theorize that the increased magnetic fields may have triggered a hallucinatory experience on the part of witnesses to haunting phenomena in the castle who slept in this bed.

Hornell Hart (1959) has noted that the fragmentary, repetitive nature of most apparitions’ behavior does not seem consistent with the hypothesis that apparitions are indications of the fully surviving consciousness of the deceased.  Several other theories of haunting apparitions, including those of Myers, Tyrrell and Roll, have already been discussed in Chapters 3 and 5, and so we will not repeat those discussions here.

The evidence for survival provided by haunting cases, while suggestive, is not particularly strong.  In many cases, a skeptic could maintain that the apparitional figures are simply hallucinations, perhaps caused by fatigue or some sort of pathological state in the witnesses.  Also, normal settling noises and other sounds may be misinterpreted as ghostly phenomena in a house with a reputation for being haunted.  It should also be realized that haunting cases, in the narrow sense of the repeated sighting of apparitions in a single location by several witnesses, are much more rarely reported than are spontaneous psi experiences.  Thus, hauntings might more easily be attributed to psychopathology or fraud than spontaneous psi cases could be.


The belief that it is possible to contact the dead through the intermediary of a living person forms a part of many formal and informal religious traditions. Ian Wilson (1987) notes that rites for contacting the dead existed in ancient Greece and observes that the Biblical tradition has Saul contacting the deceased Samuel through the mediumship of the witch of Endor.   Spiritualistic séances go back at least as far as 1000 A.D. in the Norse tradition, and mediumship was intimately associated with the phenomenon of animal magnetism or mesmerism (now called hypnosis) in the first half of the nineteenth century (Leahey and Leahey, 1983). Mediumship has of course always been associated with shamanistic religions, possibly even into prehistoric times.  Nevertheless, in most people’s minds mediumship is most clearly associated with the Spiritualist tradition that began to flourish in America and England during the second half of the nineteenth century and which is still alive in a somewhat muted form today.

The birth of the modern Spiritualist movement is usually traced to the Fox sisters, who claimed to be able to communicate with the spirits of the deceased through mysteriously produced rapping sounds. The Fox sisters’ phenomena began with a series of raps that occurred over a time period beginning in 1847 in their childhood home in Hydesville, New York.  The raps appeared to answer questions, and, when an alphabetic code was worked out, claimed to originate from the spirit of a peddler who was murdered in the house.  A body was found buried in the cellar of the house, and the Fox sisters became celebrities.  They subsequently developed a stage act in which they produced rapping messages from the deceased in front of large audiences.  The sisters later became alcoholics, and one of them confessed that she had fraudulently produced the rapping noises by popping the joint of her big toe (although she later retracted this confession).   By this time, mediumship had become a growth industry, and Spiritualism developed as a religious movement centered around mediumistic phenomena.  The heyday of Spiritualism is past, although the recent mania for “channelled” advice from the beyond and the success of television psychics such as Jonathan Edward clearly has its roots in the mediumistic tradition.

Physical Mediumship. When anomalous physical phenomena seemingly connected with the spirits of the dead are manifested in the presence of a human intermediary or medium, one is said to be dealing with “physical mediumship.” Such phenomena are typically obtained in the context of a séance, in which a group of people seeking contact with the dead, called “sitters,” gather in the presence of a medium.  Frequently, but not invariably, the medium enters a trance state as part of the ritual of contacting the dead.  The phenomena obtained may include materializations or “apports” of objects (that is, the seeming appearance of objects out of thin air), the production of ectoplasm (an alleged wispy or ghostlike substance which may form the material for the physical reconstruction of the body of an appearing dead person), the production of strange sounds, including raps, the anomalous movement of objects, including the tilting of the séance table, and the anomalous appearance of written messages, such as chalk-writing on a board of slate. This list is not meant to be exhaustive, and many other types of phenomena may be manifested.

Many physical mediums have been detected in fraud. The medium Mina Crandon, for instance, was allegedly able to obtain many physical phenomena, among them the production of wax fingerprints of her dead brother Walter.   Fraud was revealed when E. E. Dudley was able to ascertain that a sample of such fingerprints were actually those of the medium’s very much alive dentist (Hansel 1980, p. 77).

In another celebrated case, a medium named Florence Cook was allegedly able to produce a materialization of the highly attractive body of a spirit named Katie King while Cook herself was tied to a chair inside a “cabinet.”  On one occasion (and in violation of the etiquette of séance behavior), a sitter named George Sitwell grabbed the materialized form of Katie King.  The cabinet was then thrown open, and the medium’s chair was found to be empty, the ropes slipped, and the medium’s clothes to be lying in disarray about the cabinet.  Cook had herself portrayed Katie King (see Oppenheim, 1985, for more details).

While the above two exposures of fraudulent mediums took place in the nineteenth century, fraudulent physical mediums continue to be exposed in recent times.  In an incident similar to the Katie King fiasco, several spirits at the Facet of Divinity Church (endorsed by death and dying expert Elizabeth Kübler-Ross) were found to be very much alive and kicking after they had taken the extraordinary step of having sexual relations with worshipers in need of “comfort” from the beyond (see Randi, 1980, p. 9).  Melvin Harris (1986) describes the exposure of the medium Paul McElhaney.  One of the features of McElhaney’s act was the apparent materialization of carnations; however, inspection of his possessions revealed that he had hidden the carnations to be materialized inside a tape recorder prior to the séance.

Because of the high incidence of fraud, most parapsychologists today cast a wary eye at physical mediumship. There continues to be debate about the genuineness of some phenomena, but in general the observational conditions for physical mediumship have been quite poor. Ectoplasm, for instance, was conveniently asserted to be sensitive to light, necessitating a darkened room in order to avoid injury to the medium (or, more likely, the medium’s reputation). The apparent levitation of the medium D. D. Home outside of an upper story window is one incident that is still argued to be genuine by some psychical researchers; however, this alleged levitation took place under very poor observational conditions, including total darkness (Jenkins, 1982).

Mental Mediumship. In mental mediumship, messages are purportedly received from the dead through the agency of a medium.  In some cases, these messages may be relayed through the process of automatic writing, whereby the medium’s hand writes messages of which the medium claims no knowledge and for which she claims no responsibility.  Occasionally, a device such as a Ouija board or planchette is used to facilitate the production of such unconsciously received messages.  Alternatively, the medium may be “possessed” by the spirits of the dead, who then communicate directly through the vocal apparatus of the medium.  Such possession is often produced by the medium’s entering a trance state.  More rarely, the voice of the postmortem personality is heard to emanate from a point in space unoccupied by any person. This form of mediumship is called “direct voice.”  One of the lesser-known projects of Thomas Edison was the development of an ideal megaphone or “trumpet” through which the dead could speak in this manner.

In trance mediumship, the medium is often possessed by a “control” spirit, who acts as “master of ceremonies” during the séance.  Such control spirits may introduce new discarnate personalities, who then may displace the control in terms of possession of the medium’s body.  In many instances, the control is a childlike figure, such as Feda, the little Indian girl who served as the control for the medium Gladys Osborne Leonard.  In some cases, such as that of Mrs. Leonora Piper’s control Phinuit, who claimed to be a French physician serving royalty, the control spirit appears to be a totally fictional character.  Most psychical researchers have come to view such control spirits as little more than secondary personalities of the mediums.  One notable exception was George Pellew, a deceased friend of the psychical researcher Richard Hodgson, who displaced Phinuit as Mrs. Piper’s control during the 1890s.  Purportedly, “Pellew” was able to recognize 30 friends and relatives of George Pellew, adding some credence to the former’s claim to be the surviving shade of the latter.  However, the archskeptic C. E. M. Hansel (1966) has pointed out that Pellew’s family denied the authenticity of the communications from “Pellew.”

Sometimes information is provided by such ostensible deceased communicators which is accurate and which the medium would have no normal means of knowing.  For a period of time the spirit of the deceased psychical researcher Richard Hodgson served as Mrs. Piper’s control.  As reported by William James (1910), on one occasion “Hodgson” reminded a sitter of an anecdote Hodgson had related via letter to the sitter before his death.  The anecdote involved a starving couple who were praying for food.  The couple’s prayers were overheard by a passing atheist.  The atheist dropped some bread down a chimney and heard the couple thanking God.  When the atheist revealed himself as the couple’s benefactor, the wife replied, “Well the Lord sent it even if the devil brought it.”

During the sitting with Mrs. Piper, the Hodgson control asked, “Do you remember a story I told you and how you laughed about the man and woman praying?”

The sitter replied, “Oh and the devil was in it. Of course I do.”

“Hodgson” then added, “Yes the devil, they told him it was the Lord who sent it even if the devil brought it … About the food that was given them … I want you to know who is speaking.”

The provision of such seemingly accurate messages by alleged deceased communicators has rendered some psychical researchers more favorably disposed toward mental mediumship than they are toward physical mediumship.  There are, however, ways in which a medium can gain information about deceased persons without directly communicating with the spirits of the dead.  Some fraudulent mediums may conduct research on the lives of persons likely to consult them.  The medium Arthur Ford, for instance, was discovered to have kept elaborate files on prospective sitters.  Ray Hyman (1977) has described techniques whereby a medium or psychic can give a “cold reading” for a client he does not know by deliberately using vague statements, which are then progressively refined based on feedback from the client until an apparently accurate body of information has been communicated.

Mediumistic communications may also include information that is derived from obituary notices and other written records.  Sometimes such information is apparently used unconsciously by a seemingly honest medium, through a process known as cryptomnesia.  In a case of cryptomnesia, a person may read an obituary notice in a newspaper and then later “receive” this information from the apparent surviving spirit of the deceased while playing with a Ouija board.  In such cases, the medium or Ouija board operator may have forgotten having ever seen the obituary notice, although this information has presumably been retained at an unconscious level and is being used subconsciously to construct the “communication” from the deceased.  Ian Stevenson and John Beloff have described several cases in which all the information provided by a “drop in” communicator (a spirit who emerges uninvited during a séance) had previously been published in an obituary notice or other single written source (Stevenson, 1978; Stevenson & Beloff, 1980).  In one case, Stevenson was able to demonstrate that the obituary notice was on the same page of the newspaper as the crossword puzzle that the Ouija board operator worked daily.

Ravaldini, Biondi and Stevenson (1990) describe an apparent instance of communication by a Sicilian priest who had been murdered in Canton, Ohio, through a medium in Italy.  This communicator was one of the “drop-in” variety, insofar as he was unknown to any of the sitters present at the mediumistic session. The communication contained several accurate details, including a description of the murder, but these details corresponded to information that had previously been published in obituary notices.  The authors argue against an explanation in terms of cryptomnesia on the basis of the fact that “Ohio” was misspelled as “Chio” in one of the obituaries in an Italian newspaper. They argue that “Canton, Chio” would be more likely to be interpreted as “Canton, China” than as “Canton, Ohio” by an Italian medium, although this would hardly seem to constitute an airtight case against cryptomnesia.  Also, as M. H. Coleman (1991) notes, as twenty years had elapsed since the priest’s death, there was ample opportunity for alternate means of information transmission to occur.

Another possibility, if one is willing to grant the existence of psi, is that mediums may be able to use their ESP faculties to gather information about the deceased from the minds of the sitters present or from other persons or written records scattered throughout the world.  In its extreme form, this has become known as the “super-ESP” hypothesis.  (Of course, if one extends this hypothesis to include direct retrocognitive telepathy with the previously existing mind of the deceased, the super-ESP hypothesis begins to merge with the survival hypothesis.  If one grants that the minds of deceased persons can be accessed telepathically after their death, then those minds in at least some sense can be said to exist after death, inasmuch as their contents continue to be accessible through retrocognitive telepathy.)  

In one amusing application of the super-ESP theory, the psychologist G. Stanley Hall constructed a biography for a fictional niece named Bessie Beals.  He then received communications from Bessie Beals through the prominent medium Mrs. Piper that related some of the information in the fictional biography.  It is surprising that Mrs. Piper could acquire this information through ESP but remain unaware of its fraudulent nature.  In this context, it should be noted that E. E. McAdams and Raymond Bayless (1981) have argued that a real person named Bessie Beals may have existed.

Finally, recent evidence indicates that some séance records have been fraudulently altered.  Melvin Harris (1986) has charged that the British researcher S .G. Soal, who is known to have altered some of the data in his experimental work in parapsychology, altered transcripts of at least one séance in which he participated.  The case in question involved a communication from the supposedly deceased spirit of Gordon Davis, a friend of Soal’s, who turned out to be very much alive at the time of the communication.  The medium involved was Blanche Cooper.  Through Cooper, “Davis” provided an accurate description of a house that the real Gordon Davis would move into well after the séance was held. Harris notes that Davis’ future house was located near Soal’s own residence.  He charges that Soal may have looked in the window of the house to gain information as to its appearance, which he then inserted into the transcript of the prior séance.  One of these details was that of a statue of a black bird sitting on Davis’s piano.  However, a duplicate copy of the séance in question, in Soal’s own handwriting, had been sent to the Reverend A. T. Fryer, a fact that Soal had apparently forgotten when he altered his copy of the document.  The duplicate transcript held by Fryer showed no references either to Davis or to a statue of a black bird.  While obviously not proof of survival, the Gordon Davis case had stood for years as a prominent example of psi phenomena occurring in the context of mediumship.

There have been a few recent attempts to apply statistical tests to determine whether the accuracy of statements made by mental mediums exceeds that which would be expected by chance.  Robertson and Roy (2004) report the results of eight experiments designed to eliminate cues such as body language of the part of sitters and expectancy effects.  However, McCue (2004) has raised the point that Robertson and Roy’s statistical analysis used the individual statement as the unit of analysis, whereas statements cannot be treated as independent events (such as statements that the target person has an injured leg and that he uses a cane or crutch).  Also, Robertson and Roy’s evidence could be interpreted as evidence of psi powers on the part of the medium rather than as evidence for a survival discarnate personality.

Several studies of mental mediumship have been recently conducted by Gary Schwartz and Linda Russek (which are summarized in Schwartz, 2002).  Schwartz’ experiments involved a medium (often a prominent medium such as Jon Edward) giving a reading for a sitter over the phone.  The statements made by the medium are then compared to the answers supplied by a control group of college students.   However, as both Wiseman and O’Keefe (2001) and Stokes (2002a) have pointed out, the medium and the students are in much different situations.  Whereas the medium is free to throw out “Barnum” statements (statements which many people might agree with) such as “your father felt kindly toward poor people,” the college students were given a much different task in which they had to answer the question of “who felt kindly toward poor people?”  For instance, Wiseman and O’Keefe note that one such statement was “your son was good with his hands” which was affirmed by 82% of the subjects when posed as a “Barnum” statement, but only 36% of a control group “correctly” answered “the son” when posed with the question “who was good with his hands?”  Also, the sitters rated the readings given for them against readings for other sitters.  However, in most instances, the sitters heard portions of the reading given for them, so this rating was not conducted blindly.

In view of the fact that in many of Schwartz et al.’s experimental trials the sitter provided “yes/no” answers to questions and statements posed by the medium, the medium could use these answers to refine his of her statements, using the “cold reading” technique described by Hyman (1977).  As pointed out by both Wiseman and O’Keefe (2001) and Stokes (2002a), other sensory cues were provided by the subject’s breathing, movements, etc., in those trials in which the sitter was in the same room with the medium or in phone contact with the sitter with the latter’s phone unmuted.  Also, in most trials the experimenter interacting with the medium knew the sitter’s identity and thus was in a position to provide inadvertent cues through body language and facial expressions.

Finally, the statistical calculations performed by Schwartz et al., in which they found astronomical odds against their mediums’ doing as well as they did by chance, were inappropriate (see Stokes, 2002a, for more details).

Due to the counterexplanations of fraud, “cold reading” techniques, and the possible ability of mediums to gather information about deceased persons through psi, few parapsychologists today would be willing to conclude that the survival of death of the human personality has been demonstrated through the study of mediumship.

We now turn to the evidence for reincarnation, which constitutes perhaps the strongest form of parapsychological evidence for survival.


There is a body of parapsychological evidence that suggests that a process of reincarnation may take place, in which a mind or soul may survive the death of the physical body and be reborn in a new physical body, with at least some elements of its former personality (e.g., memories, emotions, or possibly “karmic debt”) intact.  As noted in Chapter 0 and elsewhere, in view of the intimate dependence of the personalities and its memories on the physical state of the brain, there are good a posteriori reasons to be skeptical that such a process could take place.  While it will be argued that the notion of reincarnation in the sense of continually recycling fields of consciousness makes sense and is even to a large extent compatible with the currently prevailing worldview of modern science, the notion that the personality, with its associated memories, emotions and beliefs could survive the dissolution of the physical brain (without being first down loaded into a computer, etc.) is fairly incompatible with the worldview of modern neuroscience.

However, some parapsychological researchers have amassed evidence that, at least in some instances, some human personalities, or portions thereof, have survived death and have been transferred to, or reborn in, new human bodies.

This evidence is roughly of three kinds. The first category of evidence consists of “readings” by psychics and other spiritual advisers, who are allegedly able to use their psychic abilities to gather information about the past lives or former incarnations of their clients. Perhaps the best known of such psychics was the psychic diagnostician Edgar Cayce, who frequently described the past lives of patients who consulted him for medical advice. Past lives as described by Cayce often involved such exotic locales as the lost continent of Atlantis and other planets.  A second line of evidence arises from the technique of hypnotic age regression, in which a hypnotized subject is led backward in time to his or her childhood and then regressed even further backward in time to previous lives.  Psychological and medical problems are often ascribed by past-life hypnotherapists to events that occurred in the patient’s previous incarnations as revealed in such past-life hypnotic regression techniques.  A third form of evidence for reincarnation consists of spontaneous reports by young children of memories relating to previous lives.  In such cases, which occur primarily in cultures having a strong religious belief in reincarnation, the child typically claims to be the reincarnation of a person who had died within the past few years.  The child may exhibit knowledge of that previous life which is difficult to explain on the basis of the child’s experiences in his or her present life.  The child may also manifest personality traits and behaviors consistent with those of the claimed former personality.  These behaviors are sometimes at variance with the behavioral norms of the culture in which the child is being raised.  There also may be birthmarks or other defects on the child’s body that seem to be related to events in the claimed previous life (often the manner of death).  As we shall see, this type of case provides the strongest evidence for reincarnation of any of the three categories of evidence discussed above.

Philosophical Background.  

Many cultures around the world subscribe to a belief in reincarnation. A partial list of such cultures would include the ancient Egyptians, Hindus, Buddhists, Jains, large numbers of Druse and Shiite Moslems, and several shamanistic traditions, including those of the native tribes of northwestern North America, the Trobriand Islanders, Australian aborigines, and the Ainu of northern Japan.  Many prominent thinkers in the Western tradition have also been reincarnationists, among them Pythagorus, Plato, Walt Whitman, Henry David Thoreau, Ralph Waldo Emerson, Henry Ford, Charles Lindberg and Tom Cruise.  The French philosopher Voltaire is responsible for the memorable quote “It is no more surprising to be born twice than it is to be born once.”

Within the Judeo-Christian-Islamic tradition, a different view has held, namely that we live but one life. Some sects adhere to the doctrine that the bodies of everyone who ever lived will be physically resurrected on the Day of Judgment.  Many sects within the Judeo-Christian-Islamic tradition hold that eternal damnation or salvation is dependent on acts committed within this one physical incarnation, a stern doctrine indeed.  

It is interesting to note that the early Christian Gnostics, including such figures as Origen in the third century A.D., taught the doctrine of reincarnation. Reincarnationist beliefs within the Christian tradition were finally suppressed, however, by an ecumenical council held in 553 A.D.  Despite the banning of reincarnation as heresy, many people within the Western culture continue to believe in reincarnation. A Gallup poll of American adults indicated that 21 percent believed in reincarnation, with another 22 percent indicating that they were “not sure” whether reincarnation occurs or not (Gallup & Newport, 1992).  A similar result was obtained in a recent poll by Farha and Steward (2006), who found that 25% college students professed a belief in reincarnation. 

It is perhaps not surprising that the belief in reincarnation is so widespread. The reincarnationist cycle of birth, death and rebirth bears many similarities to other naturally occurring cycles, such as the annual changes of the seasons, the daily cycle of light and darkness, and the chemical recycling of atoms in photosynthesis and respiration.  Just as our bodies incorporate atoms that were once parts of the bodies of other people, so it might not be too surprising if our bodies also harbored souls (or Shins) that once resided in the bodies of other persons.

Another advantage of the reincarnation process is that it renders our present incarnate state less puzzling.  Under the official Judeo-Christian-Islamic view, one lives but one human lifetime, which is but a flicker of an eyelash when compared to the 13.5 billion years or so that have elapsed since the creation of our current universe in the Big Bang as well as the eons that lie ahead before the universe’s quiet end in a “heat death” (or, less probably in view of recent findings by astrophysicists, its eventual recollapse at the time of the “Big Crunch”).  Because our lives are such infinitesimal spans when compared to the age of the universe, each conscious person must marvel at the fact that this present moment in time just happens to be one of the moments when he or she (construed as the conjunction of a physical body and personality, as in the Western religious tradition) exists.  If a moment were to be chosen at random from the history of the universe, the probability that any person would exist at that time would be essentially zero. The fact that the moment which has somehow mysteriously been selected to be “now” is also a moment at which the reader is conscious must surely seem like a miracle if the single life hypothesis is true (and the Western construal of the self as consisting one’s physical body and personality is appropriate).  The fact that “now” happens to be a moment when you are conscious would become much less surprising under the hypothesis of reincarnation, as “now” would only have to correspond to any moment in a potentially endless succession of lives rather than a single life.  If one were to allow the possibility of incarnation in nonhuman life forms, or even on other planets or in other universes, it becomes more and more probable that a particular person (construed as a center of consciousness, soul or Shin) would be conscious “now.”

Several objections have been raised to the idea of reincarnation. One, which was raised by the third century Christian philosopher Tertullian and has been reiterated by the philosopher Paul Edwards, is based on the population explosion (Edwards, 1997; Tertullian, 1997). There are many more human beings alive today than have lived at any time in the past. Thus, it is claimed, there would not be enough souls to animate each new human body, as the number of bodies must surely outrun the number of reincarnating souls.  This objection could easily be met by assuming that souls or Shins that were once housed in nonhuman beings could reincarnate in humans. (It might not be surprising that kids like dinosaurs so much if you assume they spent one hundred million years incarnated in their bodies.)  If the terrestrial animal population is not large enough, it may be that souls can be drawn from other planets (assuming that interstellar travel would not constitute any great difficulty for a soul existing outside of physical spacetime) or even from other decaying universes.  (One of the explanations for the anthropic principle, the fact that the laws and conditions of our universe seem to be very delicately balanced to support the existence of life, is that many universes are created and we of necessity exist in a universe capable of supporting life. The anthropic principle will be discussed in greater detail in Chapter 8.) 

It is also conceivable that Shins or souls might spend considerable amounts of time not housed in biological bodies.  As noted in Chapter 2, some physicists, such as Evan Harris Walker, have postulated the existence of “proto-consciousnesses” responsible for the collapse of quantum mechanical state vectors governing events that are remote in space and time from human (or other biological) observers (Walker, 2000).  Hill (2005) has observed that, if the universe has been designed, it appears to be devised for creatures or consciousnesses that inhabit the vast, inhabitable regions of outer space.  The design of such a vast cosmos for the mere purpose of entertaining a few randomly evolved, ephemeral sacks of protoplasm (such as ourselves) crawling about on a minor planet of a second rate star would be most uneconomical indeed.  Perhaps proto-consciousnesses (or souls or Shins) are as common as electrons or quarks.  If such is the case, then Edwards’ population-based argument against reincarnation carries as much force as the argument that human bodies cannot be inhabited by electrons, insofar as due to population growth, the number of human bodies must surely outrun the number of available electrons.  Indeed, later in this book, it will be argued that our essential selves are likely fields of pure consciousness akin to Walker’s hypothesized “proto-consciousnesses” and that there may be a great many such selves (mini-Shins) inhabiting a single human brain at any given time.  It is likely that these mini-Shins are, like electrons and other elementary particles, only temporarily associated with a particular brain and are being constantly recycled through a succession of biological and nonbiological host systems.  Against this view, Edward’s objection based on the growth of the human population carries no weight.

A second objection to reincarnation is that we have no memory of our previous lives. Actually, that may not always be the case. Much of the parapsychological evidence for reincarnation, to be discussed below, consists of instances in which persons have in fact claimed to remember details of their previous lives. Reincarnation could of course occur without any transfer of memory from one incarnation to another.  As discussed elsewhere in this book, a considerable body of evidence exists that memories are either physically stored in the brain or at least intimately dependent on certain brain structures.  It would be difficult therefore to imagine that memories could in general survive the dissolution of the physical brain at death. In fact, we do not remember the events of many previous days of our lives, although we did in fact live through them. Our system of memories changes over time, with some memories decaying and new ones being formed. Our essential selves, on the other hand, seem to remain unchanged over time.  We are not identical with any particular set of memories. Thus, it would be easily conceivable that one’s self could be reincarnated in a new body, while retaining no memory of one’s previous life. Several writers, including Ken Wilber (1990) and the author (Stokes, 1982a, 1987, 2002b), have in fact suggested that reincarnation might occur in just such a memory-less manner.

The parapsychologist D. F. Lawden (1989) has suggested that minds or consciousnesses experience the passage of time only when incarnated in a physical body.  After death, Lawden proposes, the mind would exist in a timeless, mystical state of identification with the entire spacetime continuum.  This mystical state of union with the cosmos as a whole is unstable according to Lawden, and so the mind’s attention once again contracts to a single stream of consciousness and one is reborn into a new physical body.  In Lawden’s view, the order among successive rebirths may not correspond to their order in physical time due to the timeless nature of the state between incarnations.  Thus, one’s “next life” may be in the Middle Ages, or one might be born again in the twentieth century and encounter one’s present self as a friend.  If one were to extend Lawden’s theory to encompass the alternate universes inherent in Hugh Everett’s “many worlds” interpretation of quantum mechanics, one could even imagine being reborn as one’s present self, but eventually experiencing a different life history as one travels up a different branch of the tree of possible futures!

A somewhat similar view has been proposed by Carroll Nash (1995c). Nash postulates the existence of a postmortem condition in which one’s mind exists in a timeless state and is capable of seeing all the events of one’s life (one’s “worldline”) at once.  He proposes that this experience may form the basis of the “life reviews” frequently reported by persons undergoing near-death experiences.  He further suggests that one might become bored with one’s own worldline and thus might be drawn to experience other worldlines as well. In Nash’s opinion, this common sharing of pain and pleasures would resolve some of the inequities of our earthly lives and would unify all minds in a single consciousness. 

Writing in The Skeptical Inquirer, a journal notably skeptical of the claims of parapsychology in general and of reincarnation in particular, Greta Christina (2005) proposes that each human being achieves a kind of immortality insofar as the worldline that comprises a human life enjoys a timeless status in the spacetime of general relativity.  As will be recalled from Chapters 2 and 5, the theory of relativity denies the existence of a unique present moment and the concept of time flow.  Thus, the continued existence of one’s worldline in spacetime, when viewed from a “timeless” perspective, confers an immortality of sorts on all human beings.  Christina’s observations bear a certain similarity to Nash’s theory, but omit Nash’s proposal that one may experience one’s own worldline repeatedly (as in the philosopher Friedrich Nietzsche’s doctrine of the “eternal return”) or experience the world lines of other creatures (much like a visitor to a four-dimensional art gallery).

Both Lawden’s and Nash’s hypotheses are of course purely speculative. Lawden explicitly notes the similarity of some of his views to those of the Hindu-Buddhist tradition.  In the Indian Vedic tradition, God or Brahman (the one Self of the universe) becomes bored with his solitary existence and splits himself into all the creatures of the earth.  The Hindu tradition has it that one’s progression from incarnation to incarnation depends on one’s level of moral development.  Persons of high spiritual development are rewarded by being reborn into more favorable conditions, while miscreants may be punished for their misdeeds in the circumstances of their next lives through a process known as karma.  According to Hindu philosophy, the goal of spiritual development is to realize the identity between one’s individual self (atman) and the universal Self of the cosmos (Brahman).  In Buddhism, the goal of spiritual development is to reduce one’s own suffering (and that of others) through the extinction of the cravings and desires that give rise to suffering (to the extent that they are invariably unfulfilled). The final aim is to achieve a state of total extinction of desire known as nirvana. Nirvana is essentially a state of extinction of the self.  Despite Buddhists’ belief in reincarnation, the Buddhist doctrine of anatta is essentially a denial of the existence of a permanent self.  Ken Wilber (1990) notes that while Buddhism denies a permanent existence to the individual soul or self, it does grant a “relative existence” to the soul.  Indeed, the doctrine of anatta seems directed primarily against the idea that personality patterns and traits have a permanent existence.  Thus, seekers of enlightenment should not cling to their present mental states.  Rather, each such seeker should see himself or herself as pure consciousness and awareness, something separate from the personality traits, memories, feelings and sensations that may form the source or objects of desire or clinging, preventing one from reaching a state of enlightenment.  The similarities between Eastern views regarding the extinction of self and union with a World Soul and Lawden’s and Nash’s views discussed above should be apparent (indeed, Lawden explicitly comments on these similarities).

An interesting element of Hindu and Buddhist doctrine is the concept of the kalpa, the great cycle beginning with the creation of the world through the splitting of Brahman and ending with the annihilation of the world (which is then created anew). One kalpa is thought to last 4.3 billion years, which is extraordinarily close to the 13.5 billion years modern physicists believe have elapsed since the creation of the universe in the Big Bang.

The parapsychological evidence is equivocal regarding the existence of the Hindu and Buddhist principle of karma, wherein one is rewarded or punished for the deeds of one’s past lives in the circumstances of one’s present life.  As will be seen, the evidence from psychic readings and hypnotic regression suggests the existence of such a principle, but these cases do not provide the strongest evidence for reincarnation.  The more compelling evidence from the spontaneous recall of past life memories does not in general suggest the existence of any moral karmic principle governing the assignment of incarnations.  

Now let us turn to a detailed consideration of the parapsychological evidence for reincarnation.

Psychic Readings  

One form of evidence for reincarnation consists of instances in which a professional psychic describes details of the alleged past lives of a client who has consulted the psychic for spiritual or medical advice. If the psychic has displayed evidence of paranormal ability by accurately describing details of the client’s life that the psychic had no apparent normal means of knowing, then the client and other observers may be inclined to accept the psychic’s description of the client’s past lives as accurate knowledge obtained through the same extrasensory abilities the psychic employed in describing the more mundane (yet at the same time more verifiable) details of the client’s present life.

By far the most famous collection of such past life readings was provided by the psychic diagnostician Edgar Cayce, who has been discussed earlier in connection with psychic healing.  Cayce, it will be recalled, was allegedly able to enter a trance and diagnose people’s illnesses, given only their names and addresses.  What is of interest in the present context is that Cayce frequently traced the cause of the illness to events occurring in a previous life of the patient.  Often the illness seemed to be a means of paying a karmic debt.  After entering his trance, Cayce would describe consulting the “akashic records,” in which the details of everyone’s past lives are recorded.  Cayce was initially surprised at the Hinduistic nature of his readings, which indicated the operation of a karmic principle governing reincarnation that was quite at variance with Cayce’s own fundamentalist Christian upbringing.  Cayce’s past life readings have been popularized in many books (e.g., Cermina, 1967; Stearn, 1967; Woodward, 1971), and form the basis for many people’s belief in reincarnation.

The following is a typical Cayce reading.  This particular reading was given for a client who was suffering from a bone cancer in her hip. Cayce traces this condition to the client’s having laughed at the suffering of the Christian gladiators in a past life during Nero’s reign in Rome.  In reading the text of Cayce’s remarks, the reader should bear in mind that Cayce typically used the phrase “the entity” in referring to the client, or more precisely, the client’s soul.  The reading is as follows:

During the period in Nero’s reign in Rome, in the latter portion of the same, the entity was then in the household of Parthesias—and one in whose company many became followers of, adherents to, those called Christians in the period, and during those persecutions in the arena when there were physical combats. The entity was as a spectator of such combats, and under the influence of those who made light of them; though the entity felt in self that there was more to that held by such individuals, as exhibited in the arena, but the entity—to carry that which was held as necessary with the companionship of those about the same—laughed at the injury received by one of the girls in the arena, and suffered in mental anguish when she later—or became cognizant of—the physical suffering brought to the body of that individual during the rest of the sojourn.  (Woodward, 1971, p. 61).

As the reader can gauge from the above passage, Cayce’s readings are not primarily remembered for the literary value of their prose. The main shortcoming of Cayce’s readings, and of psychics’ past-life readings in general, as evidence for reincarnation is that there has typically been little or no attempt to verify that the persons who formed the described past incarnations ever existed. Such attempts as have been made have been largely futile due to the extreme scarcity of records pertaining to the lives of most people who lived even as recently as one century ago.  Thus, there is little reason to believe that such readings represent anything more than the psychic’s fantasies.  In the case of Cayce, this is doubly true insofar as Cayce frequently described past lives on the lost continent of Atlantis, the existence of which would contradict a vast body of geophysical evidence, as well as on such planets as Mercury and Jupiter, which are not likely to support life.  At least some of what Cayce said about past lives has to be erroneous; possibly all of it is.

Hypnotic Age Regression

A great deal of interest in reincarnation was stirred up in the 1950s with the publication of the “Bridey Murphy” case by Morey Bernstein, a businessman and amateur hypnotist (Bernstein, 1956).  Bernstein’s subject was a Colorado housewife named Virginia Tighe.  Bernstein used the technique of hypnotic age regression to take Tighe back to the time of her early childhood.  Then he suggested that she could go even further back in time, beyond her birth, where she would find herself in “some other scene, in some other place, [and] in some other time.”  At this point Tighe began to describe another life as Bridget (Bridey) Murphy, an Irish girl living in Cork and Belfast during the early part of the nineteenth century.  While in the Bridey Murphy persona, Tighe used several Irish expressions, such as “lough” to refer to a lake, “linen” to refer to a handkerchief and “flat” to refer to a platter.  At one point, she even danced an Irish jig. She also correctly named two Belfast grocery stores and accurately stated that a big rope company and a tobacco house were operating in Belfast at the time in question.

The details of her life as Bridey Murphy were not verifiable due to the scarcity of records.  Two of her statements were challenged.  She had stated that Bridey’s husband, Brian McCarthy, had taught law at Queen’s University in Belfast.  Life magazine charged that there was no such institution, but the existence of Queen’s University was later proven.  “Bridey” also asserted that she had a metal bed.  Life charged that such beds were not introduced until at least 1850, but the psychical researcher Eric Dingwall was able to locate an advertisement for metal beds in Bridey’s home town of Cork in 1830, and the philosopher C. J. Ducasse was able to show that iron beds existed even in the eighteenth century (Ducasse, 1961).  

A more devastating criticism was delivered by the Chicago American.  That newspaper asserted that a woman named Bridie Murphy Corkell had lived across the street from Virginia Tighe when she was a little girl and suggested that an unconscious memory of this woman formed the underpinnings of Tighe’s construction of the Bridey Murphy persona under hypnosis.  Curiously, Mrs. Corkell was the mother of the editor of the Sunday edition of the Chicago American.  There proved to be some difficulty in verifying that her maiden name was Murphy, so this detail may be questionable.  In any event, the Bridey Murphy case, despite its powerful role in creating a reincarnation “flap,” is surprisingly weak in terms of detailed statements made by Tighe that were subsequently verified. This weakness will prove to be a characteristic of the hypnotic regression evidence in general, as we shall see.

Hypnotic regression to past lives has become a growth industry at least in certain facets of American culture.  Several versions of “past lives therapy” have flourished, in which it is claimed that patients’ medical and psychological problems can be alleviated when the patients discharge pent-up emotions by reexperiencing traumatic events they suffered through in their prior incarnations (see Goldberg, 1982; Wambaugh, 1978; and Weiss, 1988, for instance).  Many other people have undergone hypnotic regression to past lives outside of any therapeutic context. 

The main problem with the body of evidence that has emerged from hypnotic regression is that there has generally been little or no attempt on the part of the investigators involved in these cases to verify any of the details contained in these descriptions of past lives.  Usually, there is not even an attempt to ascertain that the person described as a former incarnation of the subject actually existed!  Thus, for the bulk of these cases, there is no compelling reason to regard these descriptions of past lives as anything other than the product of the subjects’ imaginations.

In a few rare cases, some details contained in past life descriptions obtained through hypnotic regression have been verified.  Linda Tazari (1990), for instance, reports a case in which a woman recounted a life in Spain during the sixteenth century.  The woman provided the names of several members of the Inquisition and their victims. She also accurately described buildings used by the Inquisitors and gave the correct dates of publication of several documents. Several obscure English documents and Spanish language sources had to be consulted in order to verify this information, so it is unlikely that the subject would have had easy access to this information.

In most such cases, however, it is difficult to rule out the possibility that the subject could have acquired the information given in a past-life description through normal channels.  In fact, in several instances, it has been shown that all the details provided in a past-life description were contained in a single written source, which makes it appear plausible that the subject’s knowledge of these details could be explained by the phenomenon of cryptomnesia, or unconscious memory of reading the source in question.  Melvin Harris (1986) describes two such cases.  In the first, a woman described a previous life in Britain during the third century.  Every detail in her description was found to be contained in Louis de Wohl’s novel The Living Wood.  In the second case, hypnosis was used to regress the subject back to the times when she first learned of the details given in her past life descriptions.  Under hypnosis, she was in fact able to recall reading the books that provided the material from which she constructed her past life accounts.  Jonathan Venn (1986) cites a case in which a hypnotically regressed subject gave the date of a witchcraft trial as 1556, whereas the real date was 1566.  The erroneous date had appeared in several books, one of which may have been the source of the subject’s material.  Venn also provides a statistical analysis of a single case, in which he found that statements that related to commonly available records were more likely to be true than those that related to less accessible records.   

Also, memories of past lives recovered through hypnotic regression bear a striking similarity to false memories of sexual abuse created through leading questions (and sometimes hypnosis) on the part of interviewer and therapists.  The veracity of such “recovered memories” has been strongly questioned by memory researchers such as Elizabeth Loftus (1995).

For all these reasons, hypnotic regression cases provide less than compelling evidence for reincarnation.

Spontaneous Recall

The strongest evidence for reincarnation is provided, at least at the present time, by cases in which young children spontaneously report memories of previous lives. The most prolific investigator of such cases has been Ian Stevenson, a professor of psychiatry at the University of Virginia, who, together with his coworkers and intellectual descendants, have generated a prodigious number of publications on the subject (Akolkar, 1992; Cook, Pasricha, Samararatne, Maung & Stevenson, 1983; Haraldsson, 2000a, 2000b; Haraldsson & Abu-Izzedin, 2002; Keil ,1991, 2005; Mills, 1989, 2004; Mills, Haraldsson & Keil, 1994; Pasricha, 1978, 1992a, 1992b, 1998; Pasricha & Barker, 1981; Pasricha, Keil, Tucker & Stevenson, 2005; Pasricha & Stevenson, 1979; Stevenson, 1960a, 1960b, 1966, 1970a, 1972b, 1973, 1974a, 1974b, 1974c, 1975, 1977a, 1977b, 1977c, 1980, 1983a, 1983b, 1986, 1987, 1988a, 1988b, 1989, 1990, 1992, 1993, 1997a, 1997b, 2003; Stevenson & Chadha, 1988; Stevenson & Keil, 2000; Stevenson & Pasricha, 1979, 1980; Stevenson, Pasricha & Samararatne, 1988).   

The Case of Nazih Al-Danaf.  To give an example of a case involving the spontaneous recall of a past life, Haraldsson and Abu-Izzeddin (2002) report the case of Nazih Al-Danaf, a boy living in Baalchmay, Lebanon.  At the age of one and a half years, Nazih began to speak about a former life of a man who was fatally shot by a group of armed people in Beirut.  Nazih’s family were Druze Muslims, a secretive sect that affirms the doctrine of reincarnation.  Nazih’s older sister had also spoken of a previous life.

Nazih was born in 1992 and was eight years old when he was first interviewed by Haraldsson and Abu-Izzedin.  His initial statements about a previous life included a denial that he was a child (“I am not small, I am big”), and that he carried two pistols as well as hand grenades.  According to his sister Sabrine, he stated that his first name was Fuad prior to the identification of the family in the ostensible previous life.  Although Nazih’s mother initially confirmed Sabrine’s statement, she later thought that perhaps Nazih had not uttered the name “Fuad” until after Nazih’s present and “previous” families met.

Nazih told his mother that:  “My wife is prettier than you.  Her eyes and mouth are more beautiful.”  This statement may have been the first that made her think that Nazih was speaking of a past life.  Nazih made similar statements to most of his six sisters.

Nazih stated that he had a friend who was mute and had only one hand.  He said that this friend could hold a gun in one hand and work it, getting it ready for firing.  He described how he had been killed in a shootout in which he was able to kill one of his armed opponents.

Nahiz also manifested behaviors more typical for an adult than a child, such as requesting cigarettes and whiskey, particularly during the period in which he spoke most about his previous life.

By the age of eight, Nazih had stopped talking about this previous life and his memories of this life seem to have faded.  This is a common feature of cases involving the spontaneous recall of previous lives.

Beginning at the age of two and a half, Nazih began insisting that his parents take him to village in which he lived in his prior life.  When Nazih was six years old, his father and mother agreed to drive him to this village, following his directions.  Nazih led them to a village named Qaberchamoun, about 17 kilometers from their home village of Baalchmay.  Nazih’s father stated that Nazih had mentioned the name Qaberchamoun prior to this trip, although his mother and siblings do not remember him making such a statement.

After leading his family to a particular neighborhood in Qaberchamoun, Nazih got out the car and he and his father began asking people if anyone knew of a neighbor who had been recently martyred.  They learned of one person who had died in a bomb blast, but this did not seem to fit with Nazih’s memories of being shot.  However, Nazih’s mother and sisters met a man named Kamal Khaddage at the house next to where they had parked the car.  He stated that Nazih’s memories seemed to correspond to events in the life of his father, Fuad Khaddage.  At this point, Kamal’s mother was summoned, and Nazih indicated that she was his wife in the previous life.  

The Khaddages then interrogated Nazih regarding events in the life of Fuad Khaddage.  When asked who had built a particular gate to the house, Nazih correctly replied: “A man from the Faraj family.”  He stated correctly that he kept his pistol and other weapons in a particular cupboard in the house.  Kamal’s mother (Najdijay Khaddage) then asked Nazih if she had had any accident when they were living at the house in Ainab. (The Khaddages were living in Ainab while the present house was under construction.  That house was not fully completed at the time of Fuad’s death.)  Nazih correctly stated that she had skidded on plastic nylon and fallen while picking pincones and had dislocated her shoulder.  When asked about an illness experienced by Fuad’s young daughter Fairuz, Nazih correctly stated that she eaten Fuad’s medication pills and had become poisoned.  Nazih also recollected an incident in which their car had stalled and was started up again by Israeli soldiers, who recharged the battery.

Nazih also recalled a night in which (as Fuad) he had come home drunk and found that Najdijay had locked the door and was forced to sleep outside on a rocking sofa.  He also stated that there had been a barrel in the garden that he used as a target when teaching Najdijay how to shoot.  When asked to find the barrel in questions he went to garden and pointed to it.  

In a later visit to the house of Fuad’s younger brother Sheik Addeb, he correctly recalled giving a handgun as a gift to his younger brother.  When asked the brand, Nazih correctly replied that it was a Checki 16.  When presented with another handgun and asked if it was the one, Nazih correctly denied that it was.  This incident convinced Sheik Addeb that Nazih was truly Fuad reincarnated, as no one else would have known about this gift (except possibly for Addeb’s wife).  When asked where Fuad’s original house was (where he first lived with his wife), Nazih walked down the street and correctly pointed to that house as well as the house of Fuad’s father.  Nazih also correctly stated that (as Fuad) he had built a wooden ladder that was still standing in the house.  Nazih also correctly identified his first wife and several family member in photographs.  

Haraldsson and Abu-Izzedin (2002) present a table listing 23 statements that Nazih made prior to the initial meeting between the two families at Qaberchamoun as confirmed by witnesses.  Of these 17 were correct, including the fact that Fuad had a mute friend and that there was a cave near his former house.  Haraldsson and Abu-Izzedin present this as evidence that Nazih made several correct statements about the life of Fuad Khaddage that were not the result of leading questions, physical cues and other sources of information provided by the Khaddage family and their physical surroundings.  

The Case of Rakesh Guar.  Pasricha and Barker (1981) report a case involving a boy in India named Rakesh Gaur.  In May of 1974, when Rakesh was a little more than four-years-old, he began to speak of a previous life in which he had been a carpenter named Bithal Das, who had been electrocuted at the age of 35.  He claimed that he had lived in the village of Tonk, which was about 225 kilometers distant and that he had two sons named Babu and Bhanwar Lal.  He stated that he had been a carpenter and was of the carpenter caste (a step down from his current status as a member of the Brahman caste).  Rakesh in fact displayed a great deal of interest in carpentry as a child.  He said that he had a well near his house and that he had hidden 1500 rupees at a certain location in his house.  All of the above statements proved to be accurate descriptions of the circumstances of a carpenter in Tonk named Bithal Das, who had in fact died of electrocution.  One erroneous statement that Rakesh did make was that Bithal Das’ wife’s name was Keshar, whereas in fact it was Radha.

One day in July 1976, Rakesh recognized the driver of a bus from Tonk, calling him by name.  He related his past life memories to this bus driver, who then contacted the family of Bithal Das, the ostensible previous incarnation.  Rakesh’s family then made arrangements to visit Tonk.  Upon arriving in the city, Rakesh pointed to an electrical pole, stating that he had died while working on that pole.  This statement later proved to be erroneous, as Bithal Das had in fact died when he contacted a live wire while clearing the blockage in a water drain with an iron bar.  Rakesh did recognize Bithal Das’ son Bhanwar and his widow Radha in an area near the post office, in fact picking Radha out from among a group of women.  When Bhanwar asked Rakesh what his name used to be, Rakesh replied “Arun.” This would seem to be an error, but Pasricha points out that this was in fact a name Rakesh had been called when he was younger and that Rakesh may have misunderstood the question.  Rakesh did provide a fairly accurate and detailed description of the house Bithal Das had occupied during his life in response to further questioning by Bhanwar Lal.

One of the weaknesses of the above case, as pointed out by one of its investigators, David Barker, is that no written records of Rakesh’s statements were made prior to his visit to Tonk, and that therefore one has to rely on the memory of various witnesses as to what Rakesh actually said.  Similar remarks apply to the case of Nazih Al-Danaf presented above.  Mills (2004) reports that 1.3% of the cases on record in 2004 involved written records of the child’s statement prior to the case being “solved” (i.e., the former personality identified).

Prevalence of Cases.  Reincarnation cases are not as rare as one might expect.  As of 1990, Ian Stevenson’s collection included approximately 2,500 such cases.  In a systematic survey of Northern India, Barker and Pasricha (1979) found an incidence rate of nineteen reincarnation cases per thousand inhabitants.  In a mail survey of the population of the greater Charlottesville area, Palmer (1979) found that somewhere between eight and nine percent of the respondents claimed to have memories of a past life, although Palmer did not attempt to verify the details of these memories. 

Stevenson (1986) reported that male subjects outnumbered female subjects by a ratio of two to one in his case collection at that time, and Matlock (1989) reports a similar ratio of male to female subjects in a separate analysis of published cases.   

Birthmarks.  Stevenson (1993) notes that in 35 percent of his reincarnation cases, the child is born with a birthmark or birth defect that seems significantly related to events in the life of the claimed previous personality, with similar percentages reported by other investigators (Keil, 2005; Pasricha, 1998).  Frequently such birthmarks correspond to wounds incurred at the time of a violent death.  In one such case, the subject was born with a long birthmark around his neck that seemed to correspond to the wounds received by the person whose life the subject claimed to remember; that person had died of a slit throat (Stevenson, 1974c).  Pasricha, Keil, Tucker and Stevenson (2005) report a case in which a child was born with a large nevus (wrinkled skin of unusual roughness) in his scalp.  This child claimed to be a man who was murdered by an axe blow to the head in a previous life.  Finally, Haraldsson (2000a) reports a case in which a child who had made several accurate statements about a previous personality had a large birthmark on her abdomen that seemed to correspond to marks made by the tires of the bus that had run over the previous personality abdomen, killing him. 

Stevenson (1988a, 1989, 1992, 1997a, 1997b) suggests that such birth defects may be psychologically induced. He presents evidence that some birthmarks and birth defects may be caused by maternal fright or otherwise generated by maternal sensory impressions.  In several anecdotal reports, a woman who had seen an injury or a deformity later gave birth to a child with a similar mark or deformity.  Stevenson also cites a case in which in which a man murdered another man and then cut off his limbs with a sword.  The victim’s mother cursed the murderer’s wife.  Her child was subsequently born without arms and with deformities of the feet.  Based on this evidence, Stevenson suggests that birthmarks and birth defects may be psychically induced.  Stevenson (1997a) notes that birthmarks found in reincarnation cases often differ from run-of-the-mill birthmarks in that they consist of hairless, puckered tissue, are often raised or depressed, and that some are oozing or bleeding at the time that the baby is born.

Announcing Dreams. Another feature of reincarnation cases is the announcing dream, in which a pregnant woman may dream of a deceased relative or acquaintance who informs her of his intention to be reborn as her child.  Of the twenty-four cases that Stevenson (1977c) investigated among the Haida Indians of British Columbia, fourteen were characterized by announcing dreams. In one of Stevenson’s Haida cases, a tribal elder had said that he wished to be born with only one hand so that he could avoid manual labor.  After his death, his grandchild was born without a hand on his right arm.

Unusual Interests and Skills. Many of Stevenson’s subjects displayed skills and interests that seem to represent a continuation of skills and interests developed in the claimed previous life.  Nazih Al-Danaf’s interest in guns and Rakesh Gaur’s interest in carpentry in the cases discussed above would constitute examples of this phenomenon.  Also, many subjects display phobias that seem related to their past life memories.  One of Stevenson’s cases involved a boy who recalled a past life in which he had been killed when a van crashed into the abutment of a bridge.  The child displayed a fear of that particular bridge and of automobiles in general (Stevenson, 1990).  Stevenson notes that such phobias, which occur in about one third of his cases (Cook et al., 1983), seem in most instances to relate to the manner of death of the previous personality.  He has even gone so far as to contend that unusual phobias, talents, and interests in general (including transsexualism) may have their roots in past life experiences, whether they are remembered or not.

Cases in which a person manifests a skill that he or she had no opportunity to acquire in the present life provides further evidence for reincarnation.  The same holds true for mediumship.  If a medium with no apparent mathematical skills is possessed by the spirit of a deceased mathematician and is able to solve randomly chosen partial differential equations, this would constitute a strong case for survival, as it is unlikely that a medium could acquire such a complex skill through telepathy.  However, Braude (2002) has noted that prodigies and savants often manifest complex skills, such as piano-playing and mathematical calculations that that seem inexplicable on the part of the prodigy’s training and prior experience.  In view of this fact, Braude suggests that it is premature to assume that such a manifestation of a complex skill must have been acquired in a different lifetime or through the exercise of some “superpsi” ability capable of acquiring complex skills from other living persons.  

Xenoglossy.  In a handful of cases, a medium or person remembering a past life has been able to speak in a language that he or she had no opportunity to learn normally, a phenomenon known as xenoglossy. The principal investigator of the phenomenon of xenoglossy has been Ian Stevenson (Stevenson, 1974d, 1976, 1984; Stevenson & Pasricha, 1979, 1980).  In one of Stevenson’s cases, a woman who had been hypnotically regressed to a previous life spoke in German, a language that she did not know in her normal waking state (Stevenson, 1976).  Some skepticism was expressed by German-speaking observers as to whether the subject really understood what she was saying in this case.  D. Scott Rogo (1987) also contended that this subject attempted on at least one occasion to fake knowledge of German by consulting a dictionary.  In any event, Rogo asserts, her knowledge of German was rudimentary and she was unable to keep track of long speeches and complex phrases.

Another case, investigated by Stevenson and Pasricha (1980), is quite unusual in that it resembles a case of possession more than a typical reincarnation case. (The phenomenon of possession will be described in greater detail below.) In this case, an Indian woman first spoke of memories of a previous life when she was in her thirties. Her body was apparently completely taken over by the personality of the previous incarnation.  Her primary personality had amnesia for events occurring when the previous personality was in control of the body, and the previous personality had amnesia for events occurring when the primary personality was in control of the body, although this mutual amnesia was not entirely complete.  When the previous personality was manifesting, the subject spoke Bengali, a language Stevenson and Pasricha claim she had no opportunity to learn.  Six native speakers verified that she was fluent in Bengali while in the previous personality state.  In an independent investigation of the case, V. V. Akolkar (1992) was able to determine that this subject did in fact have some training in Bengali, which of course diminishes the evidence for xenoglossy considerably.

Sarah Thomason (1987) has argued that two of Stevenson’s cases fail to provide evidence for true responsive xenoglossy (in which a subject can hold a two-way conversation in the language) as opposed to recitative xenoglossy (in which the subject may simply recite a phrase or word he may have previously memorized or may simply parrot back words presented to him by the questioner). Thomason claims that Stevenson’s subjects show an extremely limited vocabulary, that they provide only short answers, which often consist of mere repetition of phrases, when questions are posed to them, and that they make simple mistakes that are probably due to the fact that the subject understands only one or two words in a sentence.

A new case of xenoglossy has been presented by Barrington, Mulacz and Rivas (2005), with a minor correction published in Barrington (2005).  In this case, in 1933 a fifteen-year-old Hungarian girl, Iris Farczady, who had dabbled in mediumship, underwent a complete personality change, claiming to be Lucinda, a 41-year-old Spanish woman who had died earlier that year.  After the transformation, “Lucinda” spoke only in Spanish, a language that Barrington, Mulacz and Farczady claim Iris had never learned nor had to opportunity to acquire.  Still in control in at age 86 in 1998 (the time of Barrington et al.’s investigation), Lucinda has remained in existence and considers Iris to be another person, who ceased to exist in 1933.

In general, the evidence for xenoglossy is quite fragmentary.  Xenoglossy cases are extremely rare, and only four cases have received thorough investigation, three of them by Stevenson.  At least two of Stevenson’s cases are extremely weak, and in any event it would seem to be an impossible task to demonstrate conclusively that an adult subject never had enough exposure to a given foreign language to enable him or her to produce a few simple phrases (or demonstrate increasing fluency over 70 years of practice in the case of Iris Farczady).  

Prevalence of Violent Deaths.  In an extraordinarily large number of cases involving the spontaneous recall of past lives, the previous life ended in a violent death.  Such deaths occur in well over half of Stevenson’s cases (Stevenson, 1987).  James Matlock (1990) observes that this represents a substantial elevation over the rate of violent deaths in the general population, which stands at five percent.   Stevenson observes that the details of a violent death are frequently the most prominent memories in such cases.  In instances of homicide, the murderer’s name is frequently recalled, and occasionally events that the previous personality would have no way of knowing are nevertheless recalled (such as the process whereby an object came to fall on one’s head, resulting in death).  Stevenson further notes that even cases in which the death of the previous personality was nonviolent frequently involve sudden death or unfinished business (such as when a mother of young children dies or when the subject reports dying as a child in the previous life).  Stevenson believes that such unfinished business can result in past life memories being more likely to emerge in the next incarnation and can also lead to a shorter time interval before reincarnation than might otherwise be the case.  In fact, he presents evidence that cases involving a violent death involve a shorter time interval before rebirth than cases involving a nonviolent death (Stevenson & Chadha, 1988).  The average time interval between lives is, incidentally, only 15 months in Stevenson’s cases.

Stevenson offers a few speculations regarding the process of reincarnation based on his research (Stevenson, 1987).  He suggests that between lives the personality exists as a discarnate trace called a “psychophore.”  The psychophore retains images relating to the previous life.  These images are then capable of being described once the child whose body becomes associated with the psychophore develops the ability to speak.  Stevenson further notes that his cases provide little support for the hypothesis that a moral principle of karma guides the reincarnation process.

Criticisms of Spontaneous Recall Cases. Critics have attacked the evidence for reincarnation based on spontaneous recall on several fronts. First and foremost among these criticisms is the possibility that the child may have acquired the information about the previous life through normal means and consciously or unconsciously used this information to construct a past-life fantasy or hoax.  Certainly, in cases in which the recalled past life is that of a deceased member of the subject’s family, the possibility for sensory transmission of information is enormous.  In other cases, the subject’s present family may have had contact with or knowledge of the family of his claimed former incarnation.  In fact, in only about one-quarter of such cases are the two families unknown to each other (Stevenson,1986; Cook, 1986).

The high proportion of cases involving violent death in Stevenson’s collection raises the suspicion that the death of the prior personality may have received much formal and informal publicity, rendering it even more likely that the subject could have been exposed to information relating to the death through normal channels.

Keil (2005) reports that the median distance between the subject and the residence of the claimed prior personality in a sample of 1200 coded cases from Stevenson’s collection is only 14 kilometers and only a handful of cases involve distances of more than 500 kilometers.  This close proximity would be consistent with the sensory leakage theory.  On the other hand, it could be interpreted as evidence that “souls” or “psychophores” may be somehow confined in spacetime or constrained by spacetime in such a way as to not travel great distances between incarnations.  A third hypothesis would be that being born in close proximity to one’s home in the former life provides cues that trigger memories of a past life, cues that may not be available if one is reborn in a remote location.  

For a parapsychologist willing to admit the existence of psi, ESP constitutes another channel whereby the subject may have acquired information relating to the claimed past life.  In such a scenario, the subject would then use the information consciously or unconsciously to impersonate the prior personality or to construct a past life fantasy (which a confused subject might actually believe).  Stevenson counters this charge by noting that his subjects evidence no extraordinary extrasensory abilities apart from the reincarnation memories themselves.  He also points to the behavioral and emotional components of such cases (such as the manifestation of skills or phobias relating to a past life), which he claims are not so easily explainable on the basis of ESP (Stevenson, 1987). In this context, it is interesting to note that in one of three cases extensively investigated by Antonia Mills (1989), the subject did in fact display extrasensory awareness (including precognitive awareness) of events happening to the family of the previous personality after the case had developed.

Another possibility is that reincarnation cases may be consciously perpetrated hoaxes. Stevenson himself has detected several such cases. (Stevenson, Pasricha & Samararatne, 1988).  Ian Wilson (1987, 1988) has argued that a disproportionately large number of Stevenson’s cases consist of poor children remembering wealthy lives.  He contends that these cases may represent a scheme to bilk money from the family of the claimed former incarnation.  In fact, however, the evidence does not indicate any great tendency for subjects to recall past lives under better conditions than their present one (Matlock, 1990; Mills, 1989; Pasricha,1978).

One weakness of most reincarnation cases is that no written record is made of the child’s statements regarding his alleged past life prior to the attempted verification of those statements.  This allows the possibility that the child and his family may mingle their memories of what the child said with what they have subsequently learned about the previous personality through meeting and interviewing the family, consulting records, and so forth.  Stevenson has introduced the term “paramnesia” to describe such memory distortion, and he himself thinks that the easiest way to attack his research would be on the basis of the unreliability of witnesses’ memories (Stevenson, 1977b, 1987).  In fact, in only about 1.3% of Stevenson’s cases were written records made of the child’s statements prior to attempts to verify them (Keil, 2005).  On the other hand, some of these cases, such as the case of Bishen Chand (Stevenson, 1972b), are fairly impressive in terms of the number of accurate details contained in the child’s statements.  Keil (2005) notes that there are on average 25.5 documented statements made by the child claimant in cases with a written record of the child’s statements (with 76.7% of these statements verified as accurate descriptions of the life and circumstances of the claimed former incarnation).  There are an average of 18.5 statements in cases without written records, with 78.4% of the statements corroborated.  Keil takes these results as evidence against the “social contamination” hypothesis.  Also, an examination of the evidence by Stevenson and Keil (2000) found that the child claimants provided fewer details regarding their claimed past lives when there were delays in investigating the case.  Stevenson and Keil take this as evidence against the hypothesis that the stories are being embellished over time; rather, details are being forgotten and lost.  Of course, it may be possible that investigators are quicker to respond to cases in which the child has provided a lot of detailed information about the past life rather than just a few vague statements.

One concern regarding Stevenson’s reincarnation cases is that such cases may be manufactured as a result of parental or cultural encouragement. Certainly, the vast majority of Stevenson’s cases arise in cultures that already subscribe to a belief in reincarnation, such as the Hindu population of India, Druse Moslems, or the Tlinget Indians of Alaska.  Also, the features of such cases may vary across cultures.  For instance, announcing dreams and rebirth within the same family are far more common among the Native American tribes of the Northwest than among the Hindus of India (Stevenson, 1987, 1990).   Stevenson suggests that nascent cases may be suppressed in cultures hostile to reincarnation (Stevenson, 1974b).  He further notes that such cultures provide no cognitive framework in which such memories could be made intelligible.

Possession and Obsession

Closely related to reincarnation cases are cases in which a person’s normal personality is apparently temporarily or (much more rarely) permanently displaced by the personality of a deceased human being (or other entity). This phenomenon is known as possession.  A milder form of this syndrome occurs when a person merely seems to be under the influence or partial control of a discarnate personality, without the person’s primary personality being displaced. Such cases are commonly termed instances of “obsession.”

One of the classic cases of possession has come to be called the “Watseka Wonder.” It was first reported in a pamphlet by the self-proclaimed minister E. W. Stevens (1887), who in fact may have been one of the prime instigators of the phenomena.  The subject of this case was a thirteen-year-old girl named Lurancy Vennum, who in 1877 fell into a “trance,” or an apparently hysterical illness, in which she apparently became possessed by several “spirits,” including the personality of a sullen elderly woman and a young man who claimed to have lost his life after running away from home.  One of the Vennums’ neighbors, Asa Roff, whose own daughter had died twelve years previously, convinced the Vennums to allow E. W. Stevens, a “magnetic healer” and “minister,” to see Lurancy.  Stevens hypnotized the girl and suggested she replace the unpleasant personalities currently possessing her with a more pleasant personality.  Lurancy then suggested a list of control spirits, including the deceased Mary Roff, and the Roffs, who were present, readily agreed to have their daughter serve as control.  After becoming possessed by the spirit of Mary Roff, Lurancy lost all traces of her former personality, did not recognize members of her biological family, and insisted on living with the Roffs.  She lived with the Roffs for a little more than three months.  During that time, she recalled many events in the life of Mary Roff in conversations with the Roffs, including the details of a trip to Texas in 1857 and the names of many friends and acquaintances of the Roffs from the time preceding Lurancy’s birth.  She also on one occasion pointed to a collar, saying she had tatted it (which was true as applied to Mary).  She did not recall any of the details of her former life as Lurancy Vennum during the three months in question.  Finally, Lurancy’s old personality reemerged, and she returned to the home of her biological family, although the Mary Roff personality would emerge from time to time during visits between Lurancy and the Roffs.

There are several problems with this case.  First, the Roff personality was virtually suggested to a psychologically troubled young adolescent by the hypnotist minister (who also served as the main chronicler of the case).  She may have seized on the Mary Roff personality as a means of temporarily escaping a troubled home life.  Watseka, Illinois, was a small town, and Lurancy probably had ample opportunity to learn some of the details of Mary Roff’s life, especially as Mary had become insane at the time of her early and mysterious death and so may have been the subject of much town gossip.  Also, as Rodger Anderson (1980) points out, the Roffs and the Vennums had been near neighbors when Lurancy was seven. The Roff boy was Lurancy’s age and hence a probable playmate, thus affording Lurancy another opportunity to learn some of the details of the Roffs’ history.  Finally, there is always the possibility that Lurancy may have simply repeated details she heard in earlier conversations among the Roffs and that she may have recognized a child’s handiwork in the tatted collar and made the obvious inference that it was Mary’s sewing.  For all these reasons, despite its centrality in the popular literature on parapsychology, the Watseka Wonder does not present an especially strong case for possession.  

Several of Ian Stevenson’s reincarnation cases might be better interpreted as cases of possession, including the xenoglossy case discussed above. Stevenson’s collection also contains several cases in which a child’s normal personality seemed to be supplanted by the personality of a deceased person well after the child’s birth.  In fact, Stevenson himself has suggested that cases of this type might be better explained in terms of possession rather than reincarnation (Stevenson, 1987, p. 124).   

Of course, cases of ostensible possession occur frequently in religious contexts, such as when a practitioner of voodoo is possessed or “ridden” by a god or when a ritual of exorcism is performed to cure an apparent case of demonic possession within the context of Christianity.  In the vast majority of such cases, however, the possessing entity does not seem to be identifiable with any specific living or dead person, nor is there much in the way of solid evidence for the paranormal acquisition of information.  This being the case, it would seem reasonable to assume that such cases of possession are the result of suggestion, the product of attention-seeking role-playing, or constitute an especially bizarre form of multiple personality.

In cases of obsession, the subject’s personality is not supplanted by the surviving spirit of a deceased person, but is apparently under the influence of such a spirit.  Perhaps the best-described case of obsession in the annals of psychical research was investigated by the American researcher James Hyslop (1909).  The case involved a goldsmith named Frederic L. Thompson, who was suddenly seized by a desire to sketch and paint in oils during the summer and autumn of 1905.  Thompson even remarked to his wife that he felt he was an artist named Robert Swain Gifford.  Thompson had met Gifford only a few times and knew little about his work.  Gifford had died in 1905.  Thompson’s pictures, which consisted largely of seascapes, were found to correspond closely to Gifford’s work.  Upon visiting the Elizabeth Islands and Naushon Island in Buzzard’s Bay in Massachusetts, where Gifford had done most of his painting, Thompson discovered several scenes that closely resembled paintings he had recently generated under the influence of the Gifford persona.  At one point, Thompson heard a voice telling him to look on the other side of a tree.   Upon doing so, Thompson discovered Gifford’s initials carved there, together with the date 1902. Thompson did in fact live in New Bedford for a period of time during his childhood, but he claimed never to have visited the Elizabeth Islands during this time.

One of the shortcomings of this case is the fact that the subject himself served as one of the principal investigators.  Also, it would not strain one’s credulity too much to imagine that similarities between two collections of seascapes might arise purely by chance.  A skeptic could maintain that Thompson may have identified with Gifford for some strange psychological reason and carried that identification to the point that he fancied himself possessed by Gifford.

A more recent case of obsession was described by Rogo (1989).  In this case, a man was cured of transvestism after a female spirit who was apparently controlling his behavior was expelled through a rite of exorcism.  This case does not provide particularly compelling evidence of obsession, however, as the female spirit was never identified with any specific living or dead person.  Also, it is not uncommon for transvestites to talk about expressing their female personas and to distinguish such personas from their everyday male selves.

The strongest evidence for reincarnation or possession remains Ian Stevenson’s reincarnation cases.  Even those cases have their shortcomings.  As noted elsewhere in this book, given the findings of modern neuroscience, which has convincingly established that mental activity is at least intimately dependent on, if not identical with, brain activity, it is extremely unlikely that you could leave your physical brain behind and still retain all the memories, thoughts and feelings that have plagued you through this life.  Reincarnation need not involve memory.  As the ancient Greeks thought, we may drink of the river of Lethe and remember no more.  Like the elementary particles that compose our physical body, our souls or selves (construed as centers of pure consciousness) may be constantly recycled through a succession of living organisms and non-biological structures (some such structures perhaps being beyond our ken at the present time).  Memory, like a telephone number scrolled on a note pad, may reside in the structure, not the soul.  This present life (or, as we shall presently see, perhaps a small portion thereof) may be but a brief interlude in continuing journey through spacetime (and perhaps through other realms beyond our present understanding). 

Attempts to Physically Detect the Soul

We will now consider several rather colorful (and sometimes rather bizarre) forms of evidence for survival.  They all fall into the category of atte