The Red Queen_ Sex and the Evolution of Human Nature - Matt Ridley [125]
It is hard for a non-scientist to realize how revolutionary were the implications of these ideas when men like Don Symons first began to sketch them out in the late 1970s.11 What Symons was saying – that men and women have different minds because they have had different evolutionary ambitions and rewards – accords easily with common sense. But the overwhelming majority of the research that social scientists had done on human sexuality was infused with the assumption that there are no mental differences. To this day, many social scientists assume – not conclude, assume – that all differences are learnt from parents and peers by identical brains. Listen, for instance, to Liam Hudson and Bernadine Jacot, authors of a book called The Way Men Think:
At the heart of men’s psychology is a ‘wound’, a developmental crisis experienced by infant boys as they distance themselves from mother’s love and establish themselves as male. This makes men adept at abstract reasoning but vulnerable to insensitivity, misogyny and perversion.12
Through their assumption that the cause must lie in a childhood experience, the authors are condemning forty-nine per cent of the human race as ‘wounded’ perverts. How much more generous it would be if, instead of writing parables about childhood wounds, psychologists were to accept that some differences between the sexes just are, that they are in the nature of the beasts, because each sex has an evolved tendency to develop that way in response to experience. Deborah Tannen, author of a fascinating book about men’s and women’s styles of conversation called You Just Don’t Understand, while not considering the possibility that men’s and women’s natures are on average innately different, at least has the courage to argue that the differences are better recognized and lived with than condemned and blamed on personality:
When sincere attempts to communicate end in stalemate, and a beloved partner seems irrational and obstinate, the different languages men and women speak can shake the foundations of our lives. Understanding the other’s ways of talking is a giant leap across the communication gap between women and men, and a giant step toward opening lines of communication.13
Hormones and Brains
There is, none the less, a sense in which sexual differences cannot be strictly left to the genes. If a gene appeared in a Pleistocene man for, say, better sense of direction at the expense of poorer social intuition, it might have been of benefit to him. But, as well as his sons, his daughters would have inherited it from him. In them the gene might have been positively disadvantageous because it left them less socially intuitive. So its net effect, over time, would be neutral and it would not spread.14
The genes that would spread would therefore be ones that responded to signals of gender: if in a male, improve the sense of direction; if in a female, improve the social intuition. And this is precisely what we find. There is no evidence for genes for different brains, but there is ample evidence for genes for altering brains in response to male hormones (for reasons of historical accident, the ‘normal brain’ is female unless masculinized). So the mental differences between men and women are caused by genes that respond to testosterone.
We last met the steroid hormone, testosterone, in fish and birds, where it was rendering them more vulnerable to parasites by exaggerating their sexual ornaments. In recent years more and more evidence has been found that testosterone affects not just ornaments and bodies, but also brains. Testosterone is an ancient chemical, found in much the same form throughout the vertebrates. Its