Women at the heart of intelligence debate

Women are responsible for the wider intelligence of the human race – but men push it forward, a new genetics theory suggests.

Women are responsible for the wider intelligence of the human race – but men push it forward, a new genetics theory suggests.

Building on data which implies that some of the genes for intelligence are located on the female X chromosome, two German researchers argue that mutations of men's single X chromosome would increase intelligence. And they claim that women who found such men attractive would then mate and spread that useful mutation.

By preferring bright men, according to the theory published today in New Scientist magazine, women would have driven human evolution forwards towards higher intelligence at an accelerating rate.

It is this sexual selection process, running hand in hand with the survival benefits of intelligence, that has resulted in a threefold increase in human brain volume in 2.5 million years, say Horst Hameister and Ulrich Zechner, from the University of Ulm.

Crucial to proving the theory is showing that intelligence genes are unusually numerous on the X chromosome. The scientists claim to have found just such a pattern.

However, Steven Rose, the eminent professor of biology and director of the Brain and Behaviour Research Group at the Open University, is one of the dissenters in the field.

He sees no evidence for what he describes as the "completely pathetic argument" that big brains are the product of women lusting after men who painted caves.