Suspicious minds

The Folly of Fools: The Logic of Deceit and Self-Deception in Human Life. By Robert Trivers. Basic Books; 397 pages; $28. Published in Britain as "Deceit and Self-Deception: Fooling Yourself the Better to Fool Others" by Allen Lane; £25. Buy from Amazon.com, Amazon.co.uk

DECEIVING others has its advantages. Camouflage in nature is useful to the hunter and the hunted. The smarter the animal, the more likely it is to use (and detect) deception to its benefit. Humans are particularly good at exploiting trickery to get ahead—for more money, more power or a desired mate. Yet deception is difficult, regardless of intelligence. Lying often leaves us nervous and twitchy, and complicated fictions can lead to depression and poor immune function. And then there are the ethical implications.

In “The Folly of Fools” Robert Trivers, an American evolutionary biologist, explains that the most effectively devious people are often unaware of their deceit. Self-deception makes it easier to manipulate others to get ahead. Particularly intelligent people can be especially good at deceiving themselves.

Mining research in biology, neurophysiology, immunology and psychology, Mr Trivers delivers a swift tour of links between deception and evolutionary progress. Some of it is intuitive. The grey squirrel, for example, cleverly builds false caches to discourage others from raiding its acorns. Placebos are sometimes as effective as medication without the nasty side effects. Other illustrations require more head-scratching. Mr Trivers argues that competition between our maternal and paternal genes can create “split selves”, which try to fool each other on a biological level. Human memory often involves an unconscious process of selection and distortion, the better to believe the stories we tell others.

All of this deceit comes at a price. Mr Trivers suggests that the most cunning people (whether conscious fibbers or not) tend to benefit at the expense of everyone else. He highlights the way overconfident Wall Street traders may hurt investors and taxpayers at little personal risk. Then there are politicians who spin stories of national greatness to bolster support for costly wars in which they will not be fighting.

There is certainly no shortage of human folly to consider. Mr Trivers offers some fascinating evidence of our biological cunning, yet the science of self-deception often takes a back seat to his political views and scepticism of the social sciences. This book could probably do without his long digressions about the Israeli-Palestinian conflict and the Iraq war. But by the time readers reach these last few chapters, they will be wary of taking any story at face value anyway.