Review of ESP: A Scientific Evauation by C. E. M. Hansel. Introduction by Edward G. Boring. London, Mac Gibbons and Kee Ltd, 1966

British Journal of Psychiatry, 114, 1968, p. 653-8.

   The phenomena to which our attention is drawn by the parapsychologist can be classified into four classes, as defined by Professor Hansel:

   1. Telepathy, a person's awareness of another's thoughts without there being any communica­tion through sensory channels;

   2. Clairvoyance, knowledge acquired of an object or an event without the use of the senses;

   3. Precognition, knowledge a person may have of another person's future thoughts (precog­nitive telepathy), or of future events (precognitive clairvoyance)

   4. Psychokinesis, a person's ability to influence a physical object or an event, such as the fall of a die, by thinking about it.

   Beliefs in the actual occurrence of such phenomena have been a part of folklore from time immemorial. Telepathy is a new name for mind‑reading; clairvoyance for second sight; precognition for divination or premonition; psychokinesis for the active exercise of the will on events through, say, sympathetic magic or prayer to a benign deity.

   That any one of these phenomena should occur is not to be accounted for by any principle known to present‑day science; but in their order as arranged they present difficulties of increasing magnitude. It is not unthinkable, even to the hard‑boiled, that thoughts might be transferable from one individual to another along some pathway not yet discovered, and perceived by some sense organ, or some apparatus in the nervous system, which we have not yet recog­nized. What makes the evidence difficult to accept, however, is the information that tele­pathy does not appear to be governed by the inverse square law, or indeed to behave in any way of which the sciences of communication can make some sense. Clairvoyance is more difficult, since the percipient is not being given any help from the point of source of information, and he must himself by some unimaginable extension of his personality put himself in liaison with it. Precognition, if proved to occur, would totally destroy the logic of science as we have it; for by it one could become aware of effects before the existence of their antecedent causes. At the very least, a new theory of the nature of time would be called for. Psychokinesis is the most difficult of the lot, for by it changes calling for the input of energy are produced without any energy being supplied. What this amounts to is that if the phenomena claimed by parapsychology actually occur our whole understanding of nature is basically at fault; we shall have to develop new principles of a kind we cannot at present even vaguely imagine to make once again an intel­ligible scheme for the world in which we live; and we shall have to do so without any help from the present stock of parapsychological informa­tion which, wherever it is examined, shows itself to be unvalidatable, inconsistent, lawless and chaotic.

   It is, indeed, a phenomenon, nearly as remarkable as those claimed by parapsychology, that men of scientific distinction have been content on the one hand to concede that para­psychological observations should be accepted at their face value and on the other hand go on blithely continuing to use the exploded prin­ciples of natural science for the foundation of their work. To quote Professor Hansel: "Most of the leading British psychologists, for example, who have had anything to say on the matter of extra‑sensory perception, including Sir Cyril Burt, Margaret Knight, Robert H. Thouless and H. J. Eysenck, leave no doubt that they regard its existence as proved." Eysenck, for instance has written (Sense and Nonsense in Psychology, 1957, quoted by Hansel):

Unless there is a gigantic conspiracy involving some thirty University departments all over the world, and several hundred highly respected scientists in various fields, many of them originally hostile to the claims of the psychical researchers, the only conclusion the unbiased observer can come to must be that there does exist a small number of people who obtain knowledge existing either in other people's minds, or in the outer world, by means yet unknown to science.

    Professor Hansel reviews the origins and development of psychical research, and from the comprehensive account he gives it would not appear that Eysenck's appreciation of the position in any way fits the case. It would seem that every experiment that has produced positive results can be matched with repeat experiments by others who have entirely failed to confirm the earlier report. Criticism has in fact been so persistent and severe that the parapsychologists have been constrained to examine their record, to dismiss from consideration (of the question whether ESP is proved or not) all exploratory experiments, and to offer as the crucial evidence a number of experiments so small as to be counted on the fingers of both hands. Hansel proceeds to examine these crucial experiments to see whether they really hold water. The standpoint he adopts is that, ESP being a near­impossibility, no experimental result can be regarded as evidential unless rational explana­tions (minimal and sublimal sensory cues, mental habits and preferences, e.g. as exhibited by experimenters and detected by subjects, recording errors, and lastly fraud) can be elimi­nated. Put to this acid test, time and again the pretensions of the "conclusive" experiment break down. It would seem that Eysenck's "unbiased observer" has been hypnotized by the majesty of numbers of a more than astronomical magnitude. He has fallen for the glamour of demonstrations that such and such a result has a probability of only one in Ion where n is a large number, and has failed to take adequate account of systematic sources of deviation from chance expectancies of which, a priori, ESP is only the last and least probable in a long list.

   The effectiveness of Hansel's attack on the record can be illustrated by his re‑examination of the Pearce‑Pratt experiment, supposedly one of the most conclusive of them all. This was carried out over approximately six months in I933‑I934, and received its fullest account in an

article in the Journal of Parapsychology in 1954. It was organized by Rhine at Duke University; Pratt was a graduate student in the psychology department, and Pearce a student of divinity. We may describe the experiment in Hansel's own words:

The two men met in Pratt's room on the top floor of what is now the social sciences building on the west campus of Duke University. Both men synchronized their watches and fixed a time at which the test would start. Pearce then went across the quadrangle to the library, where he sat in a cubicle in the stacks at a distance of about too yards from Pratt, who from his window could see Pearce cross the quadrangle and enter the library.

   Pratt sat down at a table, took a pack of ESP cards, and, after shuffling and cutting it, placed it face downward on the right side of the table. At the time fixed for the experiment to start, he took the top card and placed it, still face down, on a book in the center of the table. At the end of a minute this card was transferred to the left side of the table, and the second card in the pack was placed on the book. In this manner, each card was placed on the book at its appointed time and then transferred to a pile on the left side of the table. After a run of 25 cards, an interval of 5 minutes elapsed, and then the same pro­cedure was followed with a second pack. Pratt did not see the faces of the cards until the end of the sitting when he turned them up to record their order. He then made a duplicate of his record, sealed it in an envelope that was later delivered to Rhine.

   In his cubicle in the library, Pearce recorded his guess as to the identity of each card lying on the book. After recording 50 guesses, he made a duplicate copy of his record sheet and sealed it in an envelope that was later delivered to Rhine. The two sealed records usually were delivered personally to Rhine before Pratt and Pearce compared their lists and scored the number of successes.

    The results obtained were phenomenal. There were four series of runs, and the average number of hits per 25 trials was respectively 9•9, 6•7, 7•3 and 9•3; the number of hits in 25 trials which is expected by chance is 5. Obviously something other than chance was operating in each of the four subseries. The odds against the overall result of 558 hits in 1850 (expected hits 370), are greater than 1022 to 1; and the result of each subseries is statistically significant.

   When discussing the experiment in 1954 Rhine and Pratt stated that the only alternative to an explanation in terms of ESP would involve collusion among all three participants. Hansel points out that this is not so; owing to the fact that Pearce as not supervised during the experiment, there are a number of ways in which he could have cheated to attain high scores. In the interval between the time when Pratt saw him disappear into the library and the

time when the two men met again to check the scores, Pearce could easily have walked back to where Pratt was conducting his part of the experiment. It would not have been necessary to obtain sight of the cards at every sitting for the final result to have been effectively influ­enced. In fact, as Hansel points out, the scores of individual runs of 25 trials show a curious bimodality, with two maxima, one between 4 and 6 and the other between 9 and 12. It would seem as if the cause of high scoring was in opera­tion on some occasions and not on others. It is also noteworthy that the experiment was conducted according to a strict timetable. If Pearce had chosen to cheat, he knew to a second the time he had available to do so. Is it possible that Pearce could have seen into the room where Pratt was at work?

   Hansel was shown over the field of operations by Pratt in 1960. Though changes had by that time been made, it emerged that the room in its original state had a large clear‑glass window that would have permitted anyone in the corridor to see into the room at the time of the experiment. This window was about 5 feet 10 inches from the floor at its bottom edge, and anyone looking through it from the corridor would have had a clear view of Pratt seated at his desk and of the cards he was handling. Another possibility was offered by a room on the other side of the corridor; from here the line of vision looking through the transom above the door was through the window into Pratt's room and down onto his desk. Though changes in the room since made it uncertain, there was a good possibility that Pearce could have made use of the opportunities offered by Room 311; in fact he could have returned to the social sciences building, have locked himself in Room 311, and observed Pratt in comparative safety by standing on a chair or table and looking through the transom. Another possibility could be borne in mind. Over the table where Pratt sat at work there was a trapdoor in the ceiling, in which Hansel found two holes, one old and covered by a metal plate, and one more recent. The attic above the trapdoor was used for storage. It would have been possible for an intruder to have placed himself above the trapdoor to see the cards on Pratt's table. This is not the end of security gaps in this experiment, and Hansel gives two further methods, the practicality of which he demonstrated by personal trial. Hansel's criticisms, not only of the mode of operation, but also of the recording methods used, have been presented and discussed before now; they met with a defence from Rhine and Pratt; and this defence, as it seems to the reviewer, is once again demolished. The detec­tive work done by Hansel has proved extremely effective.

   It is not necessary to follow Hansel into his detailed description and discussion of the other experiments which have been claimed as con­clusive. Though the possible ways of breaking through the security precautions are in some of the other experiments more complex and diffi­cult, they are nowhere impossible. In every case the foundation on which the claims of ESP are based is undermined.

   The later development of research methods is also of interest. The high‑scoring subjects who were easily discovered in the 1930s in America have since disappeared from the scene. It would seem fair to associate this with tightening up of experimental conditions. In England, in the early days of the Society for Psychical Research, extrasensory percipients were numerous. They vanished in the 19305 when Soal was being most critical, and reappeared in 1939 after Soal's volte‑face, when he started to find that almost everyone he tested had remarkable powers. Soal's most sensational experiments were con­ducted with a pair of Welsh schoolboys, to which Hansel devotes a devastating analysis.

   Hansel summarizes his main criticisms of ESP work, both on this side and the other side of the Atlantic, under eight heads, which he formulates in detail. They can be listed:

1. Inadequacy of experimental design;

2. Lack of criticism during the experiment;

3. Inadequacy of the experimental report;

4. Excessive claims made by experimenters;

5. Failure to report essential features of the experimental conditions;

6. Inability to survey the evidence impartially;

7. Inability to confirm a result;

8. Inability to predict.

    A few more words may be said here about methodological deficiencies. The most ordinary methods of improving reliability and validating results seem to have been regularly ignored. When a high‑scoring percipient has been discovered, he has never been passed on from one experimenter to another to see whether his results can be repeated. Very inadequate use has been made of mechanical and electronic recording systems to guard against trickery or error. Apparently there has been only one really satisfactory experiment when such use was made, by the U.S. Air Force Research Laboratories with VERITAC, in which 37 subjects completed a total of 55,500 trials. Neither the group as a whole, nor any single member of it displayed any evidence of ESP in the form of clairvoyance, in precognition, or in general extra‑sensory perception. Moreover ad­vantage has not been taken to use more sensitive and reliable scientific techniques, even when they are the most obviously appropriate. During a lecture given at the University of Manchester in 1950, Rhine was asked whether psychokinesis could not be measured directly with a sensitive balance. He replied that it was a good question, and they might get around to trying it some time. We do not know that they ever did, for he has never told us, though the well‑meant suggestion has been repeated many times. Perhaps the most devastating criticism of psychokinesis has been pointed out by the science writer Martin Gardner:

For decades Chicagoans have played the '26 game' in their bars and cabarets. The dice are shaken from a cup, the player betting a certain number will show up at least 26 times in 53 rolls. Obviously the tired and bored dice­girl, who tallies each roll doesn't care one way or another. Obviously the player is doing his damndest to roll the number. How does it happen that these tally sheets, year after year, show precisely the percentage of house take allowed by the laws of chance? One would expect PK to operate strongly under such conditions.

   Cheating is an ugly word, and when we are forced to consider, as we frequently are in the ESP field, whether deception has played a role, we must wonder how far it is applicable. Is it cheating when the percipient succeeds in deceiving the experimenter, against all precau­tions? When agent and percipient are matched together against the organizer of the experiment, and they succeed in deceiving him, are they cheating? Surely, it is appropriate to speculate how far the divinity students and the psychology students of Duke University may have thought Professor Rhine a cranky intellectual who could most properly be hoaxed? One wonders, indeed, how many bright spirits are secretly thumbing their noses at us all from the stolid pages of scientific reports.

   Hansel gives us a dramatic story of one effective series of hoaxes in his account of the Smith‑Blackburn experiments of 1882. In these Douglas Blackburn acted as agent, and Smith was a sensitive who could place himself in telepathic rapport with him. The Society for Psychical Research conducted an experiment in which Smith sat in a chair, eyes padded and bandaged, ears stuffed with cotton‑wool and putty, his feet on thick, soft rugs, and he himself enveloped in two very heavy blankets. At the other end of the room Blackburn was shown, with every precaution, a drawing which was to be transmitted to the brain beneath the blankets ‑a tangle of heavy black lines, curved and straight. Blackburn took it, fixed his gaze upon it, and to impress it on his retina and brain, drew and re‑drew it many times openly in the presence of the observers. He then went and stood behind Smith's chair, while Smith produced an almost line‑for‑line reproduction of Myer's original drawing. The investigators concluded that they had eliminated any possi­bility of information reaching Smith through any of the known senses.

   Years later, when all the experimenters were dead Blackburn revealed, "with mingled feelings of regret and satisfaction", how it had been done. He had also copied the drawing secretly on a cigarette paper. While pacing the room in a state of "rapport" he transferred the paper to the tube of the brass projector on his pencil. When done, he gave a signal to Smith by stumbling against the edge of the thick rug near his chair. The next instant Smith exclaimed "I have it", and "Where is my pencil?" Blackburn placed his pencil on the table, Smith put out a hand and took it and a long and anxious pause ensued. In the thick darkness under the blankets, Smith lifted the bandage from his eyes, and took out a luminous slate, by the light of which he copied the figure with extraordinary accuracy.

   If Blackburn had held his peace, this and other Smith‑Blackburn experiments might have gone down to history as conclusive proofs of ESP. Blackburn's statement gives a clear picture of the motivation of the two conspirators. Clearly the team of expert investigators from the S.P.R. (Myers, Gurney, Podmore, Sidgwick and Romanes) offered them a challenge they could not resist. They saw in these eminent gentlemen only another "superior type of spiritualistic crank". The experiments originated "in the honest desire of two youths to show how easily men of scientific mind and training could be deceived when seeking for evidence in support of a theory they were wishful to establish".

   Most people will not be inclined to regard the deception practised by Smith and Blackburn as unethical. Blackburn did indeed establish the point he was anxious to make; and at this distance of time we can regard it as a valuable contribution to knowledge. It is, however, difficult to accept a deception practised on the scientific public by a bona fide research worker as anything but deplorable. Yet history assures us that this has been done, and that there is no one of such standing in the world of science that his integrity can be accepted unquestioned. This has been demonstrated beyond any reasonable doubt by the investigation conducted by Trevor Hall (The Spiritualist, 1962) into the relationship between Sir William Crookes and Florence Cook.

   In December, 1873, Florence Cook was an attractive young lady of about sixteen years (her exact age is unknown), who had been trained by her mother and others as a physical medium. While shut up in a cabinet in an entranced state she was able to produce a spirit materialization, "Katie King", who bore a marked physical resemblance to the medium. This was a source of financial profit to the family, especially from an elderly but wealthy Manchester businessman, Charles Blackburn. At a seance on the 9th December at which Blackburn was present, one of the sitters seized "Katie King" by the arm and then by her waist, stating his conviction that he was holding Florence Cook. A highly undig­nified scene followed, in which the sceptic ac­quired some bruises and lost some of his beard, the sequel to which was that Blackburn announ­ced he would stop payment. At this serious pass, Florence Cook went to see William Crookes and offered herself for investigation. Crookes was known as a meticulous investigator, and he had previously interested himself in D. D. Home. The result was that Crookes, in his own words, "carried off the priestess from her shrine" and installed her in his own house for investigation.

   Crookes at this time was a man of 42. He had been married for seventeen years, and now had a considerable family and a wife in the later stages of pregnancy. He had behind him the discovery of thallium (1861); and still to come was his fundamental work on electrical dis­charges through rarefied gases, which opened new horizons in physics, gave to mankind the X‑ray ("Crookes's tube"), and brought him fame and honours. In due course he was to become President of the Chemical Society, President of the Institution of Electrical Engineers, President of the British Association and President of the Royal Society. His services to mankind were ultimately rewarded by a knighthood and the Order of Merit.

   The seances which were held in Crookes's home in the early months of 1874 with Florence Cook as medium and Crookes as compere took on a spectacular character, with Crookes dodging from one side to the other of the curtains which screened off the medium in the interior of the cabinet from the sitters outside. Outside, he would walk round with the materialized ghost, and be photographed with it; inside, according to his own account, he could see, and demonstrate, both medium and materialization as separate entities. In his own words:

On entering the cabinet Miss Cook lies down upon the floor, with her head on a pillow, and is soon entranced. During the photographic seances, Katie muffled her medium's head up in a shawl to prevent the light falling upon her face. I frequently drew the curtain on one side when Katie was standing near, and it was a common thing for the seven or eight of us in the laboratory to see Miss Cook and Katie at the same time, under the full blaze of the electric light.

   Who the six or seven other witnesses were is unknown; none of them ever delivered any testimony supporting that of Crookes himself. However, Florence Cook attained her aim, and the reports by Crookes were sufficient to reassure Charles Blackburn for a time.

   To cut the story short, to the reader of Mr. Hall's book there can be no reasonable doubt that Crookes stage‑managed bogus demonstra­tions, and his statements supporting the veridicity of the materialization are a pack of lies. The motivation for such extraordinary behaviour can be deduced from the subsequent history. After the Katie King seances, Crookes suddenly and absolutely abandoned any activity of a spiritualistic kind, and turned himself, with energy and devotion, to the researches which have given him undying fame, Florence Cook continued with her spiritualistic career, and was duly unmasked as a fraud not once but several times. She married, and had her lovers. Accord­ing to the detailed statement given by one of them (Anderson) to the officials of the S.P.R., she was a very highly sexed woman, a delightful companion and irresistibly attractive. In the course of their long love affair she told him of her previous relationship with Sir William Crookes, how she had been his mistress, and how the materialization of "Katie King" (who was herself) was just a device by which she had been able to live in Crookes's house, under his wife's nose, without exciting too much suspicion. Anderson thought it possible that Crookes became sexually entangled with Florence before he discovered that she was a fraud, and then was too much involved either to expose her or to break off the liaison. The revelations made by Florence, and passed on by Anderson to the S.P.R., contain a mass of circumstantial detail, a great deal of which has been confirmed.

   The story related by Trevor Hall is a compli­cated one, and involves a criminal conspiracy by the Cook family to exploit Charles Blackburn through the mediumship, once Florence had been disgraced, of her younger sister Kate. The question that concerns us here is whether Crookes can escape the charge that must be levelled against him. It is absolutely certain that if "Katie King" was no true materialized spirit, Crookes must have known it; to acquit Crookes, we mast suppose that this so‑called spirit was genuine, while Florence, her medium, we know for a fraud.

   It seems to the reviewer that the work of demolition carried out by Professor Hansel has destroyed the entire case for ESP. A large part of the ESP experiments are so ill‑controlled or ill‑recorded that we cannot be sure that such simple mechanisms as perception via subliminal sensory cues have not been excluded. In those experiments where we are driven back to consider the bare alternatives of ESP or fraud, we know that the a priori probabilities of fraud on the one hand and ESP on the other are out of all proportion to one another. Fraud must be excluded by the most rigorous precautions, preferably indeed by a simple and sensible experimental design, before ESP can be accep­ted. In fact it seems, from Hansel's presentation, not only that fraud never has been entirely excluded, but also that experimenters have never gone about their job in a thoroughly careful and business‑like way if they wished to exclude fraud and to demonstrate beyond a peradventure that they had done so. There never has been a conclusive experiment. The unbiased observer can dismiss the whole topic; there is no need for him to concern himself about it any more.

   For some this will be far too negative a conclusion. Humankind is endowed with a sense for the mystic, an appetite, an instrument which, apt though it may be for exploration of the private and inner world, yet when applied to the public world about us seems to lead always to error and self‑deception. The light within throws monstrous shadows without; and those who follow it end up by persuading themselves that they have found in man, in themselves indeed, if only in embryonic form, the attributes of gods. These thinkers represent the rearguard stragglers from defeats suffered in the Copernican, the Darwinian and the Freudian revolutions. We cannot say that such researches should be utterly abandoned. But we can ask the student of the occult to heed the warnings which are to be read in Professor Hansel's review of the failures of his predecessors. If he wishes to convince others than himself:, he should use the principles of scientific method to eliminate the alternative hypothesis.