Читать книгу Nature via Nurture: Genes, experience and what makes us human - Matt Ridley, Matt Ridley - Страница 12

Defining ‘instinct’ has baffled so many scientists that some refuse to use the word altogether. It need not be present from birth: some instincts only develop in adult animals (as wisdom teeth do). It need not be inflexible: digger wasps will alter their behaviour according to how many caterpillars they find already in the burrow they are provisioning. It need not be automatic: unless it meets a red-bellied fish, the stickleback male will not fight. And the boundaries between instinctive and learned behaviour are blurred.

But imprecision does not necessarily render a word useless. The boundaries of Europe are uncertain – how far east does it stretch? Are Turkey and Ukraine in it? – and there are many different meanings of the word ‘European’, but it is still a useful word. The word ‘learn’ covers a multitude of virtues, but it is still a useful word. Likewise, I believe that to call behaviour instinctive can still be useful. It implies that the behaviour is at least partially inherited, hard-wired and automatic, given the expected environment. A characteristic feature of an instinct is that it is universal. That is, if something is primarily instinctive, then it must be approximately the same in all people. Anthropology has always been torn between an interest in human similarities and human differences, with the advocates of nature emphasising the former and the advocates of nurture stressing the latter. The fact that people smile, frown, grimace and laugh in much the same way all over the world struck Darwin and would later strike the ethologists Irenaeus Eibl-Eibesfeldt and Paul Ekman as astonishing. Even among those inhabitants of New Guinea and the Amazon till then uncontacted by ‘civilisation’, these emotional expressions have the same form and the same meaning.²⁷ At the same time, the astonishing variety of rituals and habits expressed by the human race testifies to its capacity for difference. As usual in science, each side of the argument pushed the other to extreme positions.

Perhaps it would satisfy both (or neither) to focus on the paradox of human differences that are universally similar all over the world. After all, similarity is the shadow of difference. The prime candidate is sex and gender difference. Nobody now denies that men and women are different not just in anatomy but also in behaviour. From best-selling books about them being from different planets to the increasing polarisation of films into those that appeal to men (action) or to women (relationships), it is surely no longer controversial to assert that – despite exceptions – there are consistent mental as well as physical differences between the sexes. As the comedian Dave Barry puts it, ‘If a woman has to choose between catching a fly ball and saving an infant’s life, she will choose to save the infant’s life without even considering if there are men on base.’ Are such differences nature, nurture, or both?

Of all the sex differences, the best studied are the ones to do with mating. In the 1930s, psychologists first started asking men and women what they sought in a mate, and they have been asking them ever since. The answer seems so obvious that only a laboratory nerd or a Martian would bother to ask the question. But sometimes the most obvious things are the ones that most need demonstrating.

They found many similarities. Both sexes wanted intelligent, dependable, cooperative, trustworthy and loyal partners. But they also found differences. Women rated good financial prospects in their partners twice as highly as men. Hardly surprising, since men were breadwinners in the 1930s. Come back in the 1980s and you would surely find such a patently cultural difference vanishing. No: in every survey conducted since then, right up to the present day, the same preference emerges just as strongly. To this day, American women rate financial prospects twice as highly as men do when seeking mates. In personal advertisements, women mention wealth as a desirable feature of a partner 11 times as often as men do. The psychology establishment dismissed this result: it merely reflected the importance of money in American culture, not a universal sex difference. So the psychologist David Buss went and asked foreigners, and got the same answer from Dutch and German men and women. Don’t be absurd, he was told, Western Europeans are just like Americans. So Buss asked 10,047 people from 37 different cultures on six continents and five islands, ranging from Alaska to Zululand. In every culture, bar none, women rated financial prospects more highly than men. The difference was highest in Japan and lowest in Holland but it was always there.²⁸

This was not the only difference he found. In all 37 cultures, women wanted men older than them. In nearly all cultures, social status, ambition and industriousness in a mate mattered more to women than to men. Men by contrast placed more emphasis on youth (in all cultures, men wanted younger women) and physical appearance (in all cultures, men wanted beautiful women more than women wanted beautiful men). In most cultures, men also placed slightly more emphasis on chastity and fidelity in their partners, while (of course) being much more likely to seek extramarital sex themselves.²⁹

Well, what a surprise! Men like pretty, young, faithful women, while women like rich, ambitious, older men. A casual glance through films, novels or the newspaper could have revealed this to Buss, or any passing Martian. Yet the fact remains that many psychologists had firmly told Buss he would not be able to find such trends repeated outside the countries of the West, let alone all over the world. Buss proved something which was – at least to the social science establishment – very surprising.

Many social scientists argue that the reason women seek wealthy men is that men have most of the wealth. But now you know this is universal to the human race, you could easily turn it around. Men seek wealth because they know it attracts women – just as women pay more attention to appearing youthful because they know it attracts men. This direction of causality was never less plausible than the other, and given the evidence of universality, it is now more plausible. Aristotle Onassis, who knew a bit about both money and beautiful women, reputedly once said: ‘If women did not exist, all the money in the world would have no meaning.’³⁰

By proving how universal so many sex differences in mating preferences are, Buss has thrown the burden of proof on to those who would see a cultural habit rather than an instinct. But the two explanations are not mutually exclusive. They are probably both true. Men seek wealth to attract women, therefore women seek wealth because men have it, therefore men seek wealth to attract women. And so on. If men have an instinct to seek the baubles that lead to success with women, then they are likely to learn that within their culture money is one such bauble. Nurture is reinforcing nature, not opposing it.

With the human species, as Dan Dennett observed, you can never be sure that what you see is instinct, because you might be looking at the result of a reasoned argument, a copied ritual or a learned lesson. But the same applies in reverse. When you see a man chasing a woman just because she is pretty, or a girl playing with a doll while her brother plays with a sword, you can never be sure that what you are seeing is just cultural, because it might have an element of instinct. Polarising the issue is entirely mistaken. It is not a zero-sum game, where culture displaces instinct or vice versa. There might be all sorts of cultural aspects to a behaviour that is grounded in instinct. Culture will often reflect human nature rather than affect it.