Tuesday, 10 April 2012

Zener Cards: Above the 20%.

By Viviana Gomez - April 10, 2012

I’ve been practicing with the Zener cards for a while, looking to find out any extrasensory perception (ESP) giftedness in myself, without getting more than the average 20% of guessing. I have also tried them with everybody who wanted to volunteer for the test. Nothing yet, but I am not giving up.  I am sure there is some gifted candidate out there. I am determinate to reproduce the success that Dr. Rhine got in 1931 in his laboratory.
The Zener cards were created by Dr. Karl Edward Zener, a psychologist from Harvard University who in 1930, along with colleague J.B. Rhine, devised the card symbols that were used by Rhine in early ESP tests. Rhine called cards bearing these symbols "Zener cards" in honour of his colleague.
The Zener Cards consist in a standard pack of cards containing 25 cards, each portraying one of five symbols, viz., circle, cross, square, star, and waves. The cards would be shuffled and a receiver would then try to guess the cards that a sender would try to telepathically communicate. Or a subject might try to guess which card from the deck would be turned up next. A correct "guess" is called a "hit". Anything significantly higher than an average 20% hit in the long run would indicate some possible ESP condition.
Joseph Banks Rhine was a botanist who later developed an interest in parapsychology and psychology. Rhine founded the parapsychology lab at Duke University where he tested many students as volunteers. In the spring of 1931, Adam Linzmayer, an economics undergraduate at Duke, scored very high in preliminary Zener-card tests that Rhine ran him through; initially, he scored 100% correct on two short (nine-card series) tests. Even in his first long test (a 300-card series), Linzmayer scored 39.6% correct scores each time on three 25-card series (chance being 20%). However, over time, Linzmayer's scores began to drop down much closer to (but still above) chance averages. Boredom, distraction, and competing obligations, on Linzmayer’s part, were conjectured as possible factors bearing on the declining test results. Linzmayer's epic run of naming 21 out of 25 took place in Rhine's car.
The following year, Rhine tested, Hubert Pearce, who managed to surpass Linzmayer’s overall 1931 performance. Pearce’s average during the period he was tested in 1932 was 40%, whereas chance would have been 20%. Pearce was actually allowed to handle the cards most of the time. He shuffled and cut them.
The most famous series of experiments from Rhine's laboratory is arguably the ESP tests involving Hubert Pearce and J. G. Pratt, a research assistant. Pearce was tested (using Zener cards) by Pratt, who shuffled and recorded the order of the cards in the parapsychology lab 100 yards from where Pearce was sitting in a campus library cubicle. The series comprised 37 25-trial runs, conducted between August 1933 and March 1934. From run to run, the number of matches between Pratt's cards and Pearce's guesses was highly variable, generally deviating significantly above-chance, but also falling dramatically below-chance. These scores were obtained irrespective of the distance between Pratt and Pearce, which was arranged as either 100 or 250 yards.
In 1934, drawing upon several years of meticulous lab research and statistical analysis, Rhine published the first edition of a book titled Extrasensory Perception. He claimed in his book that he’d done over 90,000 trials and could justifiably conclude that ESP is “an actual and demonstrable occurrence.” There were attempts to duplicate these trials at Princeton, Johns Hopkins, Colgate, Southern Methodist, and Brown without success. Critics could not find evidence in Rhine’s report that he was as systematic and careful as one would expect a scientist to be who was making such an extraordinary claim.
Rhine did improve his testing techniques over the years, however. For example, he explained how it took some time before researchers realized that letting the subjects handle the cards or envelopes holding the cards opened the door to cheating. Also, in the early experiments, the experimenter and the subject were separated only by a screen. Later, they were placed in separate rooms or separate buildings to avoid the possibility of cheating or inadvertent communication by sensory cues.
In the early 1960s, Rhine left Duke and founded the Institute for Parapsychology which later became the Foundation for Research on the Nature of Man. In the 1970s, several high-scoring subjects – Sean Harribance, M.B. Dykshoorn, and Bill Delmore – were tested in the lab, shortly before Rhine’s retirement.
The technique used with Delmore, was a "psychic shuffle" in which the experimenters randomly select a predetermined order which the subject must match by shuffling the target deck. In each of two shuffle series, with fifty-two cards in a series, Delmore made twenty-five confidence calls -- all of which were completely correct. The probability of such success is only one in 5250. Skeptical statistician Persi Diaconis, who observed some informal tests with Delmore which amazed a group of Harvard faculty and students, hypothesized that the results were due to a set of complicated maneuvers that would be familiar to magical practitioners. 
Statistics of coincidence, the unreproducible results, tricks of the magic trade, suggestions, are the most frequent criticism from skeptics that refuse the extrasensory perception existence.


In the years since Rhine's pioneering work, hundreds of parapsychologists have conducted similar experiments, claiming the same positive results. Most of these researchers have moved away from the rigid patterns of Zener cards to more open-ended images, such as paintings or photographs. A survey published in New Scientist, on January 25, 1973, indicate that 25% of scientists polled considered extrasensorimotor phenomena "an established fact." Another 42% opted for "a likely possibility."
Today anyone can get the Zener cards and reproduce this test. The cards set, with the manual, are available at Rhine Research Center, but people can download them in Internet and print them at home. There is also a bunch of different software available on line to practice with. Try them in yourself, friends, relative or volunteers and create your own statistics and charts. And please, let me know your scores, I am still hopeful to find the one that can repeatedly be above the 20% hits.


Do you want to try the Zener Cards now?



Resources
·        Joseph Banks Rhine, Extra-Sensory Perception. Boston: Society for Psychical Research,
·        E. Douglas Dean, "The Plethysmograph as an Indicator of ESP," Journal of the Society for Psychical Research, 41, 1962, 351-353.
·        Fitzherbert, A. 1986. Psychic Sense. Angus & Robertson.
·        Frazier, K. 1981. Paranormal Borderlands of Science. Prometheus Books, Buffalo, New York.
·        Gardner, M. 1981. Science, Good, Bad and Bogus. Prometheus Books.
·        Gordon, H. 1987. Extrasensory Deception. Prometheus Books.
·        Wikipedia – The Free Encyclopedia
·        Brian, Denis (1982). The Enchanted Voyager. Englewood Cliffs: Prentice–Hall (A full-length biography of Rhine)
·        Gardner, Martin (1988). "The Obligation to Disclose Fraud", Skeptical Inquirer, Vol. XII No. 3.
·        Gardner, Martin (1986). Fads and Fallacies: In the Name of Science by Martin Gardner, New American Library (second edition). Chapter 25: ESP and PK.
·        Horn, S. (2009). Unbelievable: Investigations into Ghosts, Poltergeists, Telepathy, and Other Unseen Phenomena from the Duke Parapsychology Laboratory. Ecco. ISBN 9780061116902.

1 comment:

  1. I was actually tested with these before I received over 20% and still can't convince myself I wasn't cheating. Thinking I was lucky at guessing.

    ReplyDelete