Another researcher who had a high hit rate in his psi experiments was J.B. Rhine, a botanist turned parapsychologist. Rhine developed the Zener cards, a deck of twenty—five cards with five different designs: a star, a cross, a circle, a square, and wavy lines. Rhine's hypothesis was that someone with extrasensory perception should be able to predict which card would be turned up at a rate higher than chance, which is five correct cards in a deck of twenty—five, or 20 percent.

Rhine eventually found someone who appeared to have extraordinary psychic abilities-Hubert E. Pearce Jr. Pearce excelled at predicting the faces on the cards, even when Rhine and the cards were in a different building than Pearce. Pearce normally had between ten and thirteen correct guesses per run of twenty—five cards, an astonishingly...