The human brain is hard-wired to be susceptible to supernatural beliefs as a result of tens of thousands of years of evolution, a British psychologist said today.

Religion and other forms of magical thinking continue to thrive, in spite of a lack of evidence and the advance of science, because people are naturally biased to accept a role for the irrational in their daily lives, according to Bruce Hood, Professor of Experimental Psychology at the University of Bristol.

This evolved credulity suggests that it will be impossible to root out belief in ideas such as creationism and paranormal phenomena, even though they have been refuted by evidence and are held as a matter of faith alone.

People ultimately believe in them for the same reasons as they attach sentimental value to inanimate objects like wedding rings or teddy bears, and recoil from artefacts linked to evil, as if they are pervaded by a physical "essence".

Even the most rational people behave in these irrational ways, and supernatural beliefs are part of the same continuum, Professor Hood told the British Association Festival of Science in Norwich today.

To demonstrate, he asked members of his audience if they were prepared to put on an old-fashioned blue cardigan in return for a £10 reward, and had no shortage of volunteers.

He then informed them that the cardigan used to belong to Fred West, the mass murderer.

"Most hands went down," he said.

"When people did wear it, most people moved away from them. It’s not actually Fred West’s jumper. But it’s the belief that it’s Fred West’s jumper that has the effect. It is as if evil, a moral stance defined by culture, has become physically manifest inside the clothing."

Similar beliefs, which are held among the most sceptical of scientists, also explain why few people would agree to swap their wedding rings for identical replicas. The difference between attaching significance to sentimental objects, and believing in religion, magic or the paranormal, is only one of degree, Professor Hood said.

These tendencies, he said, are almost certainly a product of evolution. The human mind is adapted to reason intuitively, so it can generate theories about how the world works even when mechanisms cannot be seen or easily deduced.

While this is ultimately responsible for scientific thinking, as in the discovery of invisible forces such as gravity, it also leaves people prone to making irrational errors about what cause and effect.

"In most cases, intuitive theories capture everyday knowledge, such as the nature and properties of objects, what makes something alive, or the understanding that people’s minds motivate their actions," Professor Hood said.

"But because intuitive theories are based on unobservable properties, such theories leave open the possibility of misconceptions. I believe these misconceptions of naive intuitive theories provide the basis of many later adult magical beliefs about the paranormal."

This innate tendency means it is futile to expect such beliefs to die out as scientific understanding of the world improves. "The mind is adapted to reason intuitively about the properties of the world. Because we operate intuitively, it is probably pointless to get people to abandon belief systems. No amount of evidence is going to get people to take it on board and abandon these ideas."

Credulous minds may have evolved for several reasons. It was once less dangerous to accept things that are not true than it was to reject real facts, such as the threat posed by a nearby predator, and this may have predisposed humans to err on the side of belief. Superstition may also give people a sense of control that can reduce stress.

"I don’t think we’re going to evolve a rational mind, because there are benefits to being irrational," Professor Hood said.

"Superstitious behaviour -- the idea that certain rituals and practices and protect you is adaptive. If you remove the appearance that they are in control, both humans and animals become stressed. During the Gulf War in 1991, in the areas that were attacked by Scud missiles, there was a rise in superstitious belief.

"I want to challenge recent claims by Richard Dawkins among others, that supernaturalism is primarily attributable to religions spreading beliefs among the gullible minds of the young. Rather religions may simply capitalise on a natural bias to assume the existence of supernatural forces."