A persuasive body of research showing differences in the way men and women thought, responded, communicated and behaved in relationships and groups indicated the differences constituted almost two separate cultures, the annual Merriman Summer School in Lisdoonvarna has been told.
Dr Maureen Gaffney, chairwoman of the National Economic and Social Forum, in a lecture entitled "Ways of Knowing in Personal Relationships", said this was not to suggest men and women were essentially different, but from the same basic repertoire of psychological abilities, they focused on different things.
Dr Gaffney said boys seemed to approach the world aware that the world of other boys was arranged in a hierarchy. Status was measured by carefully tracking who was giving orders and who was taking them.
Independence - freedom from being told what to do - was jealously guarded, and this concern with dominance was believed to underlie men's legendary unwillingness to show weakness in front of other men.
Girls organised themselves differently, tending to form close friendships with a few other girls, readily sharing confidences and opening up feelings. Conversation was a way of binding together rather than just exchanging information.
They also tried to tone down conflicts and rarely challenged each other. Although girls were focused on care and closeness, this did not mean they ignored issues of power. "They, too, like to get their own way. But they do so in a subtle way, rarely challenging each other directly, using instead suggestion and evasion," Dr Gaffney said.
Evolutionary psychology was revealing that such differences might have a biological basis. They traced almost every difference between the sexes from how we talk, relate emotionally, compete with each other - back to the different evolutionary demands of being a female (an egg-maker) or a male (a sperm-maker).
Dr Gaffney said there had been enormous evolutionary pressure on males to fight for the prize of sexual access to females. There had been no such pressure on females to fight to get pregnant. These basic differences meant that males and females had developed different strategies of survival.
"For males, these are primarily the pressures to be competitive, to challenge, be aggressive (to fight off the competitors), to be risk-takers - all for the prize of sexual access," she said.
"Females, on the other hand, surrounded by so many willing mates, are under pressure to be choosy, particularly to choose a partner who will stick around to help her raise the young. These are general behavioural influences, not explanations of specific behaviour."
She warned, however, that before men became too enamoured by the idea that women were attracted by "tough guy stuff", it might be useful to learn that they were more interested in men's ability to produce genes for fighting disease than in their testosterone levels.
"There are links being established between immunology and sexual attraction. We know from animal research that the female, offered a choice between two males, always chooses the one whose immune genes (or basic defence against disease) are different from her own. These are checked out in smell," said Dr Gaffney.