Schopenhauer, the German pessimist philosopher, wrote in 1851 that only a man overcome by his sexual impulses could have given the name of the fair sex "to that undersized, narrow-shouldered, broad-hipped and short-legged race."
Despite the many differences between the sexes, from average weight and height to body fat, there has been an assumption that these are only skin deep and that intellect is essentially the same.
The recent publications of the latest in a growing body of research demonstrate that our brains are different too and fuel the fear that science may provide an antidote to demands for women's emancipation: if male dominance is all the nature's fault, then patriarchy is inevitable.
Feminist can, however, breathe a sign of relief at the new findings, which provide the first evidence from measurements of electrical activity that the brain of a woman can work faster than that of a man.
Manfred Fahle, of the University Eye Clinic in Tubingen, Germany, measured the activity by attaching electrodes to the scalp. When the subjects were asked to categorize letters, the resulting activity was significantly faster in women.
"In these instances, the women seem to perform faster, and their brain potentials have a higher frequency," he told me. Importantly, this difference does not occur for all tasks. When the subjects were asked to search for a shape among various objects, he found brain activity was the same.
Scientists have understood the underlying cause of the difference for some time. In 1990, two British teams found the difference between the sexes was triggered by a scarp of genetic material. The men who led the research - Robin Lovell Badge, of the Medical Research Council, and Peter Goodfellow, now at Cambridge University - were rewarded with an important gong, the 1995 Louis Jeanet Prize for Medicine.
Residing on the male Y chromosome, the gene switches on a cascade of genes that make testicles. These in turn bathe the body in testosterone. "Many of the differences in male and female rodent behaviour are testosterone - derived, "said Prof Goodfellow.
"If you give a female rat a short burst of testosterone shortly after birth you end up with a female that demonstrates male behaviour. But there is a lot of argument about whether a similar thing occurs in humans."
Five years ago, Anne Moir and David Jessel claimed in the book BrainSex that to believe the sexes are the same is to "build a society based on a biological and scientific lie." There are indeed many documented differences between the sexes in humans, rats and guinea pigs. However, the best known are in deep regions that control sexual behaviour, a find that is hardly surprising.
It was only last year that scientists announced they had found differences in the thin rind on the surface of the brain responsible for higher intellectual abilities. Sandra Witelson, of McMaster University, told the US Society of Neuroscience that women had 11 percent...