How Not to Test a Psychic

Parapsychology texts contain many references to Czechoslovakian clairvoyant Pavel Stepanek. Stepanek's tested "ESP" success rate of over 60% caused the 1970 edition of the Guinness Book of World Records to proclaim him "the best clairvoyant ever tested." Science writer Martin Gardner disagrees.

Gardner gives biographical sketches of the parapsychologists who designed and ran the experiments, men whose own careers were significantly enhanced by promotion of this psychic celebrity. Stepanek first began testing in 1961 with Dr. Milan Ryzl, whose "discovery" of Stepanek launched his own career in the field of parapsychology. He eventually shifted his allegiance from Ryzl to the American parapsychologist Joseph Gaither Pratt, who, as Gardner points out, was in a better position to bring Stepanek the fame and fortune he desired.

The remainder of the book is a detailed analysis of 25 papers that report on the tests conducted on Stepanek by Ryzl, Pratt, and others. Based on a careful review of the test conditions and methods, Gardner shows how Stepanek could have employed subtle techniques of deception to enhance his test scores. Gardner points that the "perfect score" (50 correct guesses out of 50 attempts) that made Stepanek famous was never replicated, and that when test controls were tightened, Stepanek's success ratio fell to the level of chance. In particular, Gardner criticizes the carelessness with which the experiments were executed. Gardner doesn't fault Stepanek (in fact, he admires his perserverance); rather, he faults the researchers who, predisposed to Stepanek's success, failed to design experiments with adequate controls. The "testing" of Pavel Stepanek is a classic example of self-interest conflicting with the interest of science, and ambition colliding with common sense.

Pavel Stepanek "retired" in 1971. Surprisingly, he emerged from obscurity in April of 1989 for an experiment in Amsterdam with parapsychologist Jan Kappers. The results of that experiment are included in a postscript to this volume.