The finding represents a dramatic twist in the battle of the sexes. In the past 100 years of IQ testing, women have lagged behind men by as much as five points.

But now females have stolen the lead.

The results have been published by James Flynn, a world-renowned expert in IQ testing, who believes the demands of the modern age are raising intelligence.

"In the past 100 years, the IQ scores of both men and women have risen, but women's have risen faster," said Flynn.

"This is a consequence of modernity. The complexity of the modern world is making our brains adapt and is raising our IQ."

One theory for the result is that the demands of juggling family life and building a career have made women more intelligent.

Another theory is that women have always had the potential for higher results but are only now realising it.

Flynn, who will publish his findings in a new book, added: "The brains of modern people are growing differently and showing increased cognitive complexity, which we measure as increases in IQ. This improvement is more marked in women than in men because women were disadvantaged in the past."

But he said more data were needed to explain the trend.

Supporting the notion that women are more than capable of taking on the stereotypically male hunter-gatherer role is Helena Jamieson, 33, a consultant who studied English literature at Cambridge.

"I think women always knew deep down that they were more intelligent - but, as the gentler sex, we were quiet about it and let men continue to believe they ruled the world."