The Establishment of Data Manipulation
in the Soal-Shackleton Experiments
The series of experiments carried out in the early 1940s by S. G. Soal with the percipient Basil Shackleton had a curious origin. Although scathingly critical of J. B. Rhine's card-guessing experiments, Soal embarked, in November 1934, on an extensive series of experiments in an endeavor to replicate Rhine's results under tighter conditions. Soal tested 160 individuals, amassing a grand total of 57,450 telepathy trials and 70,900 clairvoyance trials (Soal 1937; 1940). In July 1939, in a letter to Dr. Gibson (quoted in Thouless 1974), Soal declared: "I have delivered a stunning blow to Dr. Rhine's work by my repetition of his experiments in England . . . there is no evidence that individuals guessing cards can beat the laws of chance."
Soal (1940, 152) relates how, a few months later, his growing skepticism received a shock. During 1939, Whately Carington (1940) had been engaged in a series of experiments with drawings, in the course of which he noted that his subjects' hits tended to cluster around, rather than on, the intended target. Carington urged Soal to re-examine his data, comparing each guess with the card before and the one after the intended target card.Soal (1940, 153) continues: "It was, however, in no very hopeful spirit that I began the task of searching my records for this 'displacement' effect. And yet within a few weeks I had made two quite remarkable finds, which fully confirmed Carington's conjectures." Soal looked first at the 2,000 trials of the most promising GESP subject, Mrs. Gloria Stewart, and found significant above-chance scoring on both the precognitive "+ 1" and postcognitive "- 1" cards. The second discovery was Basil Shackleton, a man whose confidence in his ability to demonstrate telepathy had impressed Soal in 1936. Shackleton's 800 GESP trials, apparently null, showed significant above-chance scoring on the "+ I" and "- 1" cards in almost equal