An idea that beggars belief a believer

I am having trouble with an idea of which I am very fond. One's ideas are like children - one cares deeply about them, tries to nurture them, and hopes they will do well. One hopes that they will become independent and flourish on their own. It can be very hard to give them up.

For some time I have been wondering why people believe in things for which there is no, or virtually no, evidence.

I am referring to belief in supernormal and supernatural beings and forces and so include religion, spirits, astrology, telepathy and even, I would suggest, psychoanalysis. I have no desire to dissuade people from having such beliefs, but I am genuinely puzzled as to why they should be so widely held.

A clue came from my earlier ideas about science, which I concluded was an unnatural way of thinking and against common-sense. Then I came across the ideas of others that suggested that, for example, religious thinking was closer to common-sense than I had imagined. It struck me that perhaps all those beliefs that had so puzzled me were in fact part of our normal and natural mode of thinking. I then had the idea that we may be genetically pre-disposed to hold such views.

Anthropologists have yet to find a society that does not have a long- standing and well-established system of paranormal beliefs. They are universal and are usually regarded as being entirely culturally determined. However, I think that such beliefs were necessary for our primitive ancestors. When we became conscious we had to deal with a life that was filled with difficulties and we had to face the idea of death. There was a drive to find explanations for all phenomena that affected our lives. And since so much could not be explained, supernatural forces were invoked. The explanations were largely imaginative extensions of human experience - dreams for example.

Those who had explanations for the vicissitudes of life may have lived less anxious, more confident lives and so the beliefs could have provided a positive selective advantage. Is it not plausible then, that those who had a predisposition to hold such beliefs would have survived better and so there could be a genetic basis for such a predisposition?

Nowadays things might be thought of as being different. But are they? There is no difference between our brains and those of whom we might regard as having held primitive beliefs. In a study of why people thought they became ill only four out of 183 different cultures used a Western bio- medical explanation. The rest attributed illness to bad blood, witchcraft and other supernatural forces. We still find it intolerable not to have an explanation for our illnesses and often our personal explanations, particularly the psychological ones, are no less mystical.

Studies of childrens' supports the idea that there is a biological basis in belief in supernatural forces. The Swiss psychologist Jean Piaget found that children passed through a phase in which they assign properties of life to inanimate objects and believe that their thoughts can influence events. Recent studies found that children's explanation of illness was essentially mystical.

I took my idea to a friend who is an evolutionary biologist and knows about human evolutionary psychology. She and her colleague were very critical and quite persuasive that I was both naive and wrong. I had not provided good evidence for a genetic basis and other interpretations were possible.

Unlike children one must, on occasion, give up an idea. The time seems to be coming, but not quite yet. I'm encouraged by the historian Gerald Holton's observation that the graveyard of failed scientists is filled with those who gave up their ideas at the first indication that they were wrong. And even as I was writing this, I read a review of a book which seems to be very supportive of the idea and argues for a biological basis of religious belief. I ordered it, at once.

! Lewis Wolpert of University College London, is chairman of Copus (the Committee on the Public Understanding of Science).