And now consider his mate. What does she want? Not just a man who is a good hunter and a good fighter, but a man who has a track record as a hunter and fighter. In other words, an older man. And this is not only true of Stone Age couples. In a survey conducted by David Buss, 10,000 people, in 37 cultures, were polled. 'In all 37 cultures included in the international study on choosing a mate,' writes Buss, 'women prefer men who are older than they are.' (来源：英语杂志 http://www.EnglishCN.com)
Now I'm getting close to understanding why women are so critical of their bodies. Since prehistoric times they have had a hard-wired link to how they look. For tens of thousands of years it was crucial; it could be the difference between having a protector and not having one – between life and death, even.
For men it's not the same at all. The odd wrinkle or grey hair doesn't matter. Hell, it might even be an advantage. As long as you're good at throwing spears and building shelters, you'll be fine.
Twenty thousand years on, what has changed? Well, as David Buss points out, it's unlikely that a Stone Age man would have seen 'hundreds or even dozens of attractive women in that environment'. But now, when he looks at a Playboy centrefold, he is seeing a woman who has competed with thousands of other women for the part – not only that, he's seeing the best picture out of thousands.
And it's not just centrefolds, is it? Just look at newsreaders – mostly, it's a pretty girl and a grey-haired man. Message to men: relax. Message to women: panic! And then there are the girl groups, and the short-skirted girl on Countdown, and even the characters in the Harry Potter films, where the boys are allowed to look like geeks but the girl must look like a model.
As the art critic John Berger wrote: 'Men look at women. Women watch themselves being looked at. This determines not only the relations of men to women, but the relation of women to themselves.' It's a tough one, isn't it?
Surely guys can understand that, at least. If it happened to us, we'd have a meltdown, too.