All in the mind

Interesting news from the world of conjuring. Magicians don’t believe in magic any more. Marc Salem, one of the new breed of sceptical illusionists, isn’t a clairvoyant or a mind-reader but a ‘professor of non-verbal communications’. And he boosts his university income by sitting in on CIA interviews to help the spooks decide when a suspect is lying. I certainly wouldn’t like to face him across the interrogation room. He’s as wide as he is tall, and he wears a black frock-coat which makes him look like a cross between a mad rabbi and a Victorian undertaker. His beard is unnervingly neat, he has shrewd little I-can-see-through-you eyes, and his huge white skull has apparently been blasted clean of hair by the electromagnetic storms of his inextinguishable brain.

His show is well worth catching, a mixture of maths, theatre, psychology and stand-up. He starts with a simple trick which he invites us to try at home. Think of a number between 0 and 50. It has to be a two-digit figure, the numbers can’t include an even number, nor can they be the same. (By making these qualifications the range has been narrowed from 50 numbers to just eight: 13, 15, 17, 19, 31, 35, 37 and 39). For some reason nearly everyone picks 37. To make the ‘reveal’ more impressive, write the number on a piece of paper before you start. Here’s another. Ask someone to think of a number between one and four. By creating uncertainty about whether one and four are included in the options, you reduce people’s likely choices to two and three. Practically everyone chooses three.

The next trick is about lying. We were alerted to the telltale signs: scratching the nose or chin, a cracking voice, folded arms, a closed fist, shifting the weight from foot to foot, and so on.