J. Gaither Pratt

Pratt's name is attached to the Duke laboratory's most famous result because he was the one physically handling the cards. In the distance series of 1933 and 1934, Pratt sat in the Social Sciences building turning cards at agreed one-minute intervals while the subject Hubert Pearce sat in the library across the quadrangle recording his calls, each man sealing and dating his own record before the two were compared in front of J. B. Rhine. The design was intended to remove every channel that had been complained about in the earlier work at once: the experimenter could not see the subject, the subject could not see the cards, and neither record could be adjusted after the other was known.

The scores that came back were far above chance and became the single result the Duke group leaned on hardest for the next thirty years. Pratt spent much of his career defending the details of that afternoon's arrangements, because the criticism of the series has always turned on architecture rather than statistics, on where the doors and windows were rather than on the arithmetic. He was, by most accounts including hostile ones, meticulous in reporting what he had actually done, which is a large part of why the argument about the series has stayed technical instead of collapsing into accusation.

In 1940 Pratt was the lead author of Extra-Sensory Perception After Sixty Years, a volume written with Rhine, Charles Stuart, Burke Smith and Joseph Greenwood which did something unusual for a contested field: it collected the published objections to the Duke work, stated each one in the critic's own terms, and then answered it. Contemporary skeptics did not accept the answers, but the book set a convention in parapsychology that a defence should begin by restating the attack accurately, and it is still cited for that reason. Pratt later left Duke for the division of parapsychology at the University of Virginia, where Ian Stevenson was building a very different research programme around reported memories of previous lives.

There Pratt ran long series with the Czech subject Pavel Stepanek, who was tested for years by multiple investigators in several countries, and who produced a persistent though small effect on a task involving hidden cards in sealed envelopes. The Stepanek work is now discussed chiefly as an example of how a single co-operative subject can sustain an entire research programme, and of how difficult it is to interpret a result that only one person in the world produces. Pratt himself was consistent to the end that the case for psi rested on accumulated small effects and never on any one dramatic sitting.