Man or woman, same difference
Valentine's Day looms. The usual rows of cards, fluffy pink for girls and laddish blue for boys, are in the shops. But are men and women really so very different when it comes to romance - or anything else?
Evolutionary psychologists, nearly all of them male and American, would argue that back in the primordial swamp the most successful hunter-gatherers attracted the prettiest wives. In this picture, prettiness is a genetic indicator of fecundity and of good "feminine" homemaking and mothering skills.
Never mind that there is no evidence that looking like Keira Knightly and being a good mum correlate or have ever correlated. But then, fascinating though its speculations may be, evolutionary psychology's urge to universalise often makes it run the risk of being ideology, not science.
The evolutionary ideologist's woman looks after the children, sweeps the cave and keeps the home fires burning to cook the sabre-toothed tiger stew for when Daddy gets home from his hunter-gathering.
They also base their claims about the universal, genetic nature of gender differences on surveys of patterns of attraction around the world.
One survey has shown that in the matter of sexual jealousy, whereas men worry about sexual infidelity, women are more anxious that their man will become emotionally attached to another partner.
Another (of 52 nations) shows that men are more driven by a search for sexual variety than women. Most important of all was a 37-nation survey showing that women are attracted by dominant, wealthy, high-status, older men, whereas men everywhere seek youthful nubility and do not care about the status or wealth of women.
The trouble with these studies is that they blithely assume that genes explain these patterns without testing the social alternative. When that is investigated, the genetic foundations look rather shaky.
Two re-analyses of the 37-nation study, for example, have shown that in societies where women can gain access to wealth and status through education and a career rather than marriage to a man, they are less likely to be attracted by those characteristics in a potential mate. Denmark would seem to be a prime example of this: the women do not aspire to nubility; if anything, it is the men who have to use appearance to attract women.
Most recently, a meta-analysis of the 46 analyses that have surveyed this issue challenged the notion that men and women are all that different psychologically. In the majority of traits (78 per cent), the differences between men and women are either non-existent or small.
According to this meta-analysis, it turns out that the near-universal belief that boys are better than girls at maths is not true. In fact, there is no overall difference.
Nor do girls in general have lower self-esteem than boys. It is widely believed they have because their self-esteem nosedives on entering puberty: in fact, boys' self-esteem falls just as much. In most respects, the genders communicate in the same way: forget about men interrupting much more than women and being much less self-revealing.
Only a handful of the cherished nostra of evolutionary psychology survive this analysis.
It is true that women do not masturbate nearly as much and they are not up for casual sex to anything like the same degree. They physically attack others dramatically less often. But I am still far from convinced that these differences are genetic, although I concede that others may well be.
My three-year-old son's fascination with large farming machinery, for instance, is hard to explain in any way other than genes - it is certainly not something copied from me, my wife or his older sister.
Overall, however, my impression is that nearly all of the differences between our offspring are clearly traceable to differences in the care they have received - some of it provoked by the feelings that their gender provokes in us.
The evidence suggests that, to a very large degree, we almost do start as blank slates when it comes to gender difference. Don't believe the evolutionary hype. Most of the "differences" are not inborn - they're just a convenient excuse for flogging things like pink and blue Valentine's cards.
Oliver James is a child clinical psychologist and author of The Selfish Capitalist - Origins of Affluenza and of Affluenza - How to be successful and stay sane
Sexual jealousy study: Buss, DM, 2000, The Dangerous Passion, Bloomsbury
Study of 52 nations: Schmitt, DP et al, 2003, Journal of Personality and Social Psychology, 85, 85-104; Schmitt, DP et al, 2005, Behavioral and Brain Science, 28, 247-311
Thirty-seven nation study: Buss, DM, 1989, Behavioral and Brain Science, 12, 1-49
Re-analyses of 37-nation study: Eagly, AH et al, 1999, American Psychologist, 54, 408-23; Kasser, TM et al, Psychological Science, 10, 374-7
Meta-analysis of 46 analyses: Shibley-Hyde, J, 2005, American Psychologist, 60, 581-92.