350 | 32 TURING AND THE PARANORmAl
Elephants, giraffes, lions, pelicans, and zebras
Soal conducted his new trials in London in 1940 and 1941 during the Blitz. His subject was
Basil Shackleton, a photographer who had approached Soal several years before boasting of
his telepathic prowess. Although Shackleton’s scores in the original trials were unexceptional
when compared with Mrs Stewart’s, they too shot up when what Soal called the ‘displacement
effect’ was taken into account.^13 For this round of testing, Soal dispensed with the Zener cards
on the grounds that, ‘after using them for five years’ he ‘had grown very sick of these somewhat
arid diagrams’. The new cards he employed depicted five animals: an elephant, a giraffe, a lion,
a pelican, and a zebra. Since wartime paper shortages made it impossible to have a thousand of
them printed, Soal devised a method of testing that required only five cards.^14
The new tests were conducted in Shackleton’s photography studio, in two rooms with a con-
necting door that was left open. There were four participants: Shackleton, identified as the
‘percipient’ (P), an ‘agent’ (A), and two experimenters (EA and EP). In one of the rooms agent A
sat across the table from EA, while in the other percipient P sat across a table from EP. Elaborate
precautions were taken to safeguard against any non-telepathic communication among the
participants: for instance, a plywood screen into which a 3-inch aperture had been cut sepa-
rated EA from A, in front of whom the five cards were laid face down inside a box open on one
side so that only she could see them.^15 Outside observers monitored the tests, which proceeded
as follows.
On his side of the table, EA (nearly always Soal himself ) would remove from his briefcase a
list on which twenty-five random sequences of the digits 1, 2, 3, 4, 5, were written. (In most tri-
als the list was prepared ‘from the last digits of the seven-figure logarithms of numbers selected
at intervals of 100 from Chambers’s tables’; in a few cases Tippett’s tables were used, or bone
counters in five different colours were drawn from a cloth bag.^16 ) EA would then call out ‘one’,
look at the first number on the list, and hold a corresponding card up to the aperture for agent
A to look at. If the card read 4, A would lift the fourth card from the left just high enough to
see which animal it portrayed, and would then let the card fall back. At this point percipient
P would write down a telepathic guess as to which animal the card depicted: E for elephant, G
for giraffe, L for lion, P for pelican, or Z for zebra. When the session was concluded, EA and EP
would check the order of the cards and correlate the letters that P had written down with the
numbers that EA had called, taking note of all ‘direct hits’, ‘precognitive hits’, and ‘post-cognitive
hits’.^17 From a statistical standpoint the results were hugely impressive, with Shackleton scoring
far above chance for both precognitive and post-cognitive hits.
Parapsychology in the 1940s
How did Turing come upon his knowledge of parapsychological research? It seems improbable
that he was a reader of The Proceedings of the Society for Psychical Research, where Soal published
his findings.^18 Nor was he likely to have been in the audience in 1947 when Soal gave the SPR’s
Myers Memorial Lecture and presented another set of impressive results—obtained during tri-
als with the aforementioned Gloria Stewart. The most likely scenario is that Turing became
acquainted with Soal’s research when he was in Cambridge in 1947–48, possibly through the
agency of C. D. Broad. A Fellow of Trinity College, Broad was an active member of the SPR,