ESP, A Scientific Evaluation
Ever since Joseph Banks Rhine, a botanist-turned-parapsychologist, began his systematic study of psi (his term for “psychic”) phenomena, he has enjoyed an unusually favorable popular press and an unusually unfavorable academic one. Long, laudatory articles about him have been appearing for decades in mass circulation magazines (e.g., “A Case for ESP” by Aldous Huxley, Life, January 11, 1954). Arthur Koestler has compared Rhine’s discoveries to the Copernican Revolution. Today’s skeptical scientists. Koestler says in The Sleepwalkers, resemble those Italian philosophers who refused to look through Galileo’s telescope at Jupiter’s moons because they knew in advance that such moons did not exist. Many otherwise sophisticated people, I would guess, take it for granted that ESP and other psi powers have been conclusively demonstrated by workers in the field, and that only a few pigheaded professors refuse to look through Rhine’s telescope at the towering mountain of scientific evidence.
For thirty years professional psychologists, using sophisticated modern techniques, have been trying to duplicate the experiments of the parapsychologists, and they remain unconvinced. Unfortunately, their monotonously negative results are too dull to interest Time or Newsweek; to learn about them one must subscribe to the academic journals. Last year, for instance, the Journal of Psychology (Vol. 60, pp.313-18), reported on a carefully designed series of ESP tests by Richard C. Sprinthall and Barry S.Lubetkin. Fifty subjects were divided into two equal groups and each group was given a standard ESP test. One group took the test without “motivation”; the other was told that anyone who guessed twenty out of twenty-five ESP test cards correctly would immediately be given a hundred dollars. No one won any money. There was no significant difference in the results obtained from the two groups, and neither showed any evidence of ESP.
THIS TEST had been prompted by Rhine’s repeated assertions that financial reward provides strong motivation for ESP, and that “subject motivation to score high has long stood out as the mental variable that seems most closely related to the amount of psi effect shown in test results.” Indeed, the most sensational result ever obtained by Rhine occurred during the Depression when he kept offering Hubert Pearce, one of his star subjects, a hundred dollars for each top card he could call correctly in a pack of ESP cards. They halted the test by mutual consent after Pearce had correctly named twenty-five cards in a row. No one else was present on this occasion, and Rhine’s published accounts of exactly what happened are vague. (I once tried to get a few easily remembered details out of Pearce by correspondence—he is now a Methodist minister in Arkansas—but he flatly refused to discuss the incident.) Nevertheless, Rhine always cites this in his lectures as the most remarkable demonstration of clairvoyance he has ever witnessed, giving the odds of 298,023, 223,876,953,125 to 1 that it could have happened by chance. (I always felt sorry for Pearce with respect to this event. He was poor at the time and needed the money, but when the test was over, and he was owed $2,500, Rhine explained that he had just been joking.)
No one can deny that some of the most remarkable results in the history of psi research were obtained when subjects were strongly motivated. Can it be that strongly motivated subjects are often strongly motivated to cheat? This is the opinion of C. E. M. Hansel, Professor of Psychology at the University of Manchester, and author of ESP: A Scientific Evaluation. After a careful study of the most important ESP experiments by Rhine and his British counterpart, S. G. Soal, Hansel has become convinced that more hanky-panky has been going on than even the skeptics have suspected.
Consider the classic series of tests that Soal made in the early Forties with a photographer named Basil Shackleton. When Hansel subjected the records to a statistical analysis, a curious anomaly turned up. Soal’s score sheets had been ruled with a double line after every five blanks, and Shackleton’s “hits” were concentrated (with odds greater than 100 to 1 against such a concentration) on the third and fourth lines of each group of five. It is hard to think of any reason why ESP would conform to the pattern of ruled lines on blank score sheets, but easy to understand if someone had gone over the scores to beef them up a bit and had been too stupid to make the beefing random. Hansel’s discovery set off a noisy dispute among British psychic researchers when he published it in Nature, in 1960, although not a line about this appeared in the US press. When Hansel tried to get a look at Soal’s original score sheets, on which chemical tests would, of course, reveal any tampering, he was told by Soal that they had all been lost on a train in 1946. (Soal had written in 1954 that the original records had been preserved and “could be rechecked by anyone at any future time.”) Moreover, one of Soal’s assistants in the Shackleton tests told Hansel that she had glanced through a hole in a screen and had seen Soal altering figures.
When Rhine heard of these disclosures, he invited Hansel to visit his laboratory, then affiliated with Duke University, to look over his records. This proved to be bad judgment. Hansel did visit Rhine’s laboratory, and stayed until he was asked to leave. Every major series of tests that he investigated in depth turned out to have gigantic loopholes, hitherto unnoticed (or unmentioned) by Rhine, that permitted skulduggery of the most elementary sort.
RHINE’S MOST RESPECTED series of tests, to which he refers constantly in his later writings, was a series of longdistance tests with Pearce, conducted in 1933-34 by Rhine’s long-time assistant, J. G. Pratt. Pearce and Pratt met in Pratt’s office, synchronized their watches, fixed a time for the test to start, then Pearce walked across the Duke quadrangle to the library, where he sat in a cubicle in the stacks. Pratt went through a supply of fifty ESP cards, taking them one at a time and placing each card face down in front of him for one full minute. Then he turned over all the cards, made two records of their order, sealed one in an envelope and delivered it to Rhine. Pearce also made duplicate records of his guesses and delivered one to Rhine. There were thirty-seven such sittings. Pearce’s scores, throughout, were much too high to be explained by chance.
Anyone who reads the informal accounts of the Pearce-Pratt tests, in books by Rhine and Pratt, cannot but be impressed by the lengths to which Rhine went to rule out collusion between Pratt and Pearce. But the one thing neither Pratt nor Rhine ruled out was the possibility that Pearce did not stay in his cubicle. He could have sneaked back across the campus, entered a vacant room across the corridor from Pratt’s office, stood on a chair, and peeked through the transom and a clear-glass hallway window, just behind Pratt’s shoulder, to get a good view of the cards while Pratt recorded them. While Hansel was at Duke, he asked one of Rhine’s researchers to run through a pack of ESP cards while he (Hansel) locked himself in an office down the hall. Hansel tip-toed back, stood on a chair, and peeked through a crack over the door. He scored twenty-two hits out of twenty-five cards, to the complete mystification of the researcher. Hansel does not say that Pearce cheated in a similar manner, or in any of several other easy ways permitted by the experiment’s amateurish design. He does say that, because this obvious bias factor was not guarded against, the entire Pearce-Pratt series is now highly suspect. Hansel puts it this way:
One would expect that anyone in Pratt’s position would have examined the room carefully and have taken elaborate precautions so that no one could see into it. At least he might have covered the windows leading to the corridor. Also, the cards should have been shuffled after they were recorded, and the door of the room might well have been locked during and after the tests. These experiments were not a first-year exercise. They were intended to provide conclusive proof of ESP and to shake the very foundations of science. If Pratt had some misgivings, there is no evidence that he ever expressed them…. Again, Rhine might well have been wary of trickery, for neither he nor Pratt were novices in psychical research.
HANSEL’S BOOK reaches its climax in the chapter on Soal’s last great series of tests, his experiments with two Welsh schoolboy cousins, Glyn and Ieuan Jones. Soal wrote up his results in a book called The Mind Readers, which was favorably reviewed by every leading newspaper in England except the Manchester Guardian. Even the distinguished Sir Cyril Burt, editor of the Journal of Statistical Psychology, praised Soal for the care in which he conducted his tests and called them “unrivaled in the whole corpus of psychical research.”
They were unrivaled, it is true, but not in “care.” The Jones boys were repeatedly caught signaling to each other, using various visual and auditory codes. As soon as the boys improved their signaling methods, Soal promptly concluded that he had succeeded in persuading them to stop cheating. Hansel’s analysis of Soal’s book demolishes everything except the sad, comic, unintentional revelation of one parapsychologist’s extraordinary naiveté.
Rhine’s published work on PK (psychokinesis), his term for the ability of the mind to move such objects as falling dice or to levitate a table, is far more revolutionary than his work on ESP. Not even Soal has been able to find evidence for PK, and it has long been a joke among psychologists that PK somehow fails to operate in British laboratories. Skeptics are always asking Rhine: If PK is strong enough to control a rolling die, how come it can’t move an eyelash on a smooth surface in a vacuum, or rotate a tiny needle, suspended magnetically so that there is virtually no friction? Hansel writes that when Rhine was asked this in 1950, after a lecture at Manchester, he replied by saying that such a test was a splendid idea and one he might get around to trying sometime. Hansel later learned that Rhine had been making such tests for years, back at Duke, but when Rhine gets negative results he likes to keep them under wraps. To this day, the failure of PK to display itself in such a simple, direct fashion is one of those subtle psi mysteries that true believers find the hardest to explain.
IN THE COLD LIGHT of Hansel’s analysis, what should be the layman’s attitude toward the claims of parapsychology? First, he should realize that the claims are claims of fact, not theory. There is no theory of psi phenomena. If the facts are true, they are independent of all known laws of science, and no new laws have been formulated to explain them. Second, he should realize that these facts are historical questions. Psi experiments are not repeatable in the way that other experiments in physics or psychology are. Star subjects such as Pearce and Singleton invariably and inexplicably lose their former powers. One does not ask: “Is this Methodist minister, Hubert Pearce, clairvoyant?” but “Did Pearce, at a certain time in his youth, actually call twenty-five ESP cards correctly by clairvoyance?” Such a question is of the same type as: “Did the medium D. D. Home, in 1868, actually float horizontally through an open third-floor window in London, turn around in the air, and float back in again, feet first?” Such claims must be approached in the spirit recommended by David Hume in his famous essay on miracles: One must ask if present evidence for the alleged event is so strong that any other explanation of the evidence would be even more miraculous.
It is also important to realize that one’s attitude toward parapsychology should be completely independent of one’s metaphysics. Sigmund Freud, who believed in ESP, was an atheist. Most people I know who admire Rhine are atheists. On the other side, I once heard a devout theist argue that one of God’s great gifts to humanity is the insulated brain in which thoughts can be kept inviolate. The questions raised by parapsychology must be answered, in the only way they can be answered, by considering all the evidence bearing on them and making an estimate of the probability of ESP that is free of emotional bias. Because the claims of parapsychology run so strongly against the entire corpus of known physical laws, the burden of proof is surely on the claimants. They may win over most laymen by means of uncritical reports in the popular press, but they are unlikely to impress other psychologists until they produce evidence strong enough to justify what Koestler is absolutely right in calling (if the facts are true) a “Copernican Revolution.”
So far, the strongest evidence has come from the work of Rhine and Soal, but I do not think that anyone can read Hansel’s book with an open mind and believe that evidence compelling. There is one hopeful new development. The US Air Force Research Laboratories has devised a type of ESP experiment in which a computer called VERITAC is substituted for the experimenter and his assistants in such a way as to rule out such common sources of bias as fraud and recording errors. “If 12 months of research on VERITAC can establish the existence of ESP,” Hansel concludes, “the past research will not have been in vain. If ESP is not established, much further effort could be spared and the energies of many young scientists could be directed to more worth-while research.”