Brain scans of a group of young men and women have revealed significant distinctions in the activity of a part of the brain - the limbic system - associated with emotions such as pleasure, fear and happiness.
The results support other research showing that the biological differences between the sexes seem to extend to differences within the brain which may account for the stereotypical behaviours observed in men and women.
Eric Cantona's emotional outburst at a football match on Wednesday night, where he attacked a man in the crowd who was hurling abuse, is a classic example of how men lash out. ``Men often express their emotions through overt aggression,'' said Ruben Gur,professor of neuropsychology at the University of Pennsylvania, Philadelphia.
``Women deal with their emotions more symbolically by talking about their feelings more than men, who often sulk and say `what's there to talk about?'''
Professor Gur and colleagues recruited 61 volunteers under the age of 45 - 37 men and 24 women - and measured the metabolic activity of their brains in scanners that could detect how fast blood glucose was used up when the subjects were resting but awake.
In general terms there were no significant differences between the sexes except for activity levels in the limbic regions.
Men were more likely to be active in the temporal limbic region, which primates share with most other animals, including reptiles, whereas women were more active in the cingulate region of the brain, which, in evolutionary terms, is far more recent. ``The cingulate region is particularly developed in higher animals likes apes and humans, and we believe it deals with emotions more symbolically,'' Professor Gur said. The temporal limbic region deals with more base responses - for instance, like an angry crocodile lashing out in a rage.
``When was the last time you saw a lizard trying to understand the finer points of its attraction or repulsion for another lizard?'' Men are more likely to take the lizard's way out in dealing with emotionally charged situations, he said.
Professor Gur, in common with a growing number of psychologists and behavioural researchers, believes the stereotypical differences between men and women are the result of fundamental biological distinctions laid down at birth, rather than differences inthe way boys and girls are brought up.
Psychological differences between adult men and women are also well known. Women excel in verbal and emotional discrimination tasks whereas men tend to be better with spatial tasks involving co-ordinating brain activity with muscle movement.
The Cantona affair, pages 38, 40