They might not agree but men and women do think differently, for a study has found that there are subtle genetic variations in their brains.

Researchers have identified hundreds of genes that are switched on and off differently in the male and female brains, a finding which suggests that many behaviour patterns regarded as typical of each sex could be founded on nature and nurture.

According to the researchers, dozens of mental traits and skills differ between men and women. They include empathy, aggression, risk-taking, navigation and the qualities that are valued most in a sexual partner.

Moreover, men and women also differ in their approach to finding sexual partners. Men generally place a higher value on youth and good looks, while women are often more attracted by status, the study found.

In fact, while the two sexes have the same basic genes, many of these are more active in the brains of only one sex. These gender-specific patterns of gene expression could affect many aspects of behaviour.

'The obvious question to follow is whether or not the signatures of sex in the brain have physiological significance for brain physiology and/or behaviour. Our results suggest that variation in expression of genes in brain may be an important component of behavioural variation within as well as between species,' British newspaper The Times quoted lead researcher Dr Elena Jazin of Uppsala University as saying.

In fact, the differences could also explain sex variations in mental health and neurological diseases: Women, for instance, are more at risk of depression and Alzheimer's.

'Knowledge about gender differences is important for many reasons. For example, this information may be used in the future to calculate medical dosages as well as for treatments of diseases or damage to the brain,' Dr Jazin said.

The results of the study have been published in the Public Library of Science Genetics journal.