Chicanery, credulity and gall

Does it matter that more than half the population believes in psychic phenomena? That almost all television programmes on the topic seem to promote psychic claims? That people spend millions of pounds a year on visiting psychics and mediums? That scientists are accused of suppressing "The Truth" about psychics? If the claimants are charlatans it does, and many of them are. In Deception and Self-Deception Richard Wiseman, himself both a parapsychologist and an accomplished magician, investigates psychic fraud, seances, the powers of godmen and the claims of psychics who "help" the police. In the process he ranges over the natural failings of human observation to really devious tricks. If you thought you were hard to fool read this book.

Deception and Self-Deception is a collection of previously published papers and they vary in quality and interest. Among the most interesting are experiments with three well-known British psychic detectives - they did worse than three students at describing actual crimes when presented with objects associated with the crimes - and studies of Indian godmen who claim to work miracles. Sai Baba has over 20 million devotees. Though frequently suspected of fraud he has never been caught cheating and all the films available show nothing suspicious - unless you think that materialising holy ash and pulling small trinkets out of nowhere is suspicious in itself.

In 1992 an Indian newspaper claimed to have film footage showing Sai Baba using trickery when he apparently materialised a gold watch and gave it to the prime minister. Opponents of Sai Baba were delighted at the expose and the story spread, even to The Independent, which said that the film showed "tawdry sleight-of-hand". Wiseman, together with his Icelandic colleague Erlendur Haraldsson, showed that the truth was not so simple. The film was poor quality and reveals only enough detail to conclude that trickery could have occurred - not that it definitely did.

Controlled studies are needed and Wiseman reports several in which he and Haraldsson tried to track down other godmen and women and get them to produce the holy ash inside a plastic bag, or when filmed by magicians. Their travels make fascinating reading though they did not return with convincing film of either miracles or fraud.

In all these examples Wiseman is wisely cautious in his conclusions. His investigations reveal the difficulty of getting unambiguous evidence of psychic fraud and the importance of designing experiments carefully and with respect for the needs of the claimants. However, he is less cautious in other places. His incisive analysis of the famous 19th-century medium, Eusapia Palladino, is an example of the kind of scepticism that some psychical researchers positively detest. At seances in Naples in 1908 Eusapia performed for investigators from the Society for Psychical Research who subsequently wrote the famous Feilding report, concluding that she had genuine powers. Objects moved and levitated, hands appeared from the "cabinet" in the corner of the room and the sitters felt touches and breezes. Wiseman does a thorough job of taking the whole story to pieces and examining the possible role of confederates, secret door panels and other magician's specialities.

But what about the other side of the story? A footnote informs the reader that the paper was controversial at the time of publication and gives references to the responses - something of an understatement given the vehemence of those responses. One critic described Wiseman's suggestions as "improbable and absurd" and he responded by accusing her of making ten major errors - which she then refuted. A second critic, who described Wiseman as a "determined critic" making impractical assumptions, was accused of nine major errors and of fundamentally misunderstanding the argument. He responded that the errors were "Wiseman's own" and accused him in turn of serious distortion and misrepresentation. There is no doubt that Wiseman has done a useful and provocative job in revisiting the Palladino case, but I could not help feeling that it was a little unfair for the reader only to see one side of the battle.

A collection of one person's papers is bound to give a one-sided view but this, plus the fact that there is no index, seriously restricts the value of this book for the serious researcher - and after all, these are largely research papers written for researchers. For the general reader there are some fascinating stories, but do not expect an introduction to or overview of deception and self-deception.

Susan Blackmore is senior lecturer in psychology, University of the West of England, Bristol.