Wednesday, March 22, 2006

We need a big brain to hold so much nonsense

Excerpts from a review of Six Impossible Things Before Breakfast: The Evolutionary Origins of Belief by Lewis Wolpert.

We exceed all other animals in our capacity to believe things for which there is no rational evidence — a category that, in Wolpert’s reckoning, includes all the world’s religions, and every species of paranormal and supernatural belief, from aromatherapy to zen. It needs a big brain to hold so much nonsense....

... [O]nce our tool-inventing ancestors had got used to the idea that effects had causes, they started to wonder what caused distressing and seemingly inexplicable events such as illness, death and natural disasters, and to answer these questions they invented religious belief.


The human brain is, it seems, powered by a “belief engine” that makes us eager to seize on causal explanations for events, irrespective of whether they have any basis in truth. Wolpert gives many examples of this, both from history and from contemporary life. Around half of all Americans believe in astrology, and 72% believe in angels. Belief in “good luck”, and ways of ensuring it, extend to the superintelligent. The Nobel prizewinning physicist Niels Bohr kept a horseshoe nailed to the wall above his desk and, when asked whether he believed it would bring him luck, replied: “Not at all. I am scarcely likely to believe in such nonsense. However, I am told that a horseshoe will bring you luck whether you believe in it or not.”

Neuroscience reveals that belief and logic activate different parts of the brain, and where belief and logic clash, humans will almost always opt for belief, sticking to it obstinately despite adverse evidence. Students offered alternative sets of statistics will choose the one that confirms their prejudices, and a dogged reliance on existing beliefs shows up emphatically in matters affecting health. The belief that vitamin supplements provide a defence against illness, and that “natural” products are not harmful, is widespread even among educated people. Wolpert does not condemn such superstitions, for beliefs, it seems, can keep you healthy, whether they are valid or not. Experiment shows that all sorts of pain can be relieved with a sugar-pill placebo, provided the patient believes in its curative powers. Credulity may ensure survival better than logic.

The same applies with religious beliefs. Surveys suggest that religious people are happier, more optimistic, less prone to strokes and high blood pressure, more able to cope with life’s problems and less fearful of death than the irreligious. It follows that belief in the supernatural is an evolutionary advantage, and our ability to have such beliefs must, Wolpert deduces, have been partly determined by our genes. Religious people might rejoice at that, concluding that God has wired us up to believe in him. But for Wolpert, the wiring is no more divine than our guts or toenails, or any other part of our evolved anatomy. Mystical raptures, similar to those reported by the devout, can be produced, he points out, by mental illness or hallucinogenic drugs and this, too, indicates that religion depends on neural circuits in our brain that accident or malfunction can activate. Some neuroscientists now link spiritual experiences with specific brain areas. Stimulating the brain of subjects with electromagnets causes tiny seizures in the temporal lobes that induce the subjects to believe they have spiritual experiences. The visions of St Teresa, it is suggested, may have been symptoms of temporal-lobe epilepsy.

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