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When E. O. Wilson suggested in his 1975 book Sociobiology that every facet of human behaviour was influenced by our genetic inheritance, he launched a furious battle that still rumbles on. Colleagues publicly insinuated that it was theories such as his that had led to the Nazi gas chambers.

Wilson argued that behaviour and social structures were extensions of genes that existed because of their superior adaptive value. We have "genes favouring spite" because we have worked out that it has selective advantages; we are "absurdly easy" to indoctrinate, therefore we must have conformer genes. And those clinging to notions of modern sophistication could think again: he said that humans still operated within a code as simple as that of our cave-dwelling ancestors.

More recently, evolutionary psychologists have ventured into increasingly inflammatory territory. In 2000, US scientists Craig T. Palmer and Randy Thornhill enraged feminists and scientists alike by declaring that rape was a "natural adaptation" that had evolved as an alternative mating strategy.

And because men are easily aroused, young women should avoid provocative clothing.

Two years later, Stephen Pinker raised hackles with the Blank Slate , an attack on the notion that a newborn baby's mind is a clean sheet waiting to be shaped by experience. Perhaps least palatably, this proposed that violence was part of our genetic design. Aggressive parents may often have aggressive children, but Pinker argued that this violence was not learnt in a "cycle of violence" but inherited.

Like others in his field before him, he expected to spark moral explosions: but he maintained that to understand violence one had to first understand why it had paid off in evolutionary terms.