The Rational Optimist_ How Prosperity Evolves - Matt Ridley [45]
Thus, the entire edifice of human cooperation and exchange, upon which prosperity and progress are built, depends on a fortunate biological fact. Human beings are capable of empathy, and are discerning trusters. Is that it, then? That human beings can build complicated societies and experience prosperity is down to the fact that they have a biological instinct that encourages cooperation? If only it were that simple. If only the arguments of Hobbes and Locke, of Rousseau and Voltaire, of Hume and Smith, of Kant and Rawls, could be brought to such a neat and reductionist conclusion. However, the biology is only the start. It is something that makes prosperity possible, but it is not the whole explanation.
Besides, there is still no evidence that any of this biology is uniquely developed in human beings. Capuchin monkeys and chimpanzees are just as resentful of unfair treatment as human beings are and just as capable of helpful acts towards kin or group members. The more you look at altruism and cooperation, the less uniquely human it appears. Oxytocin is common to all mammals, and is used for mother-love in sheep and lover-love in voles, so the chances are that it is available to underpin trust in almost any social mammal. It is necessary, but not sufficient to explain the human propensity to exchange. On the other hand, it is highly likely that during the past 100,000 years human beings have developed peculiarly sensitive oxytocin systems, much more ready to fire with sympathy, as a result of natural selection in a trading species. That is to say, just as the genes for digesting milk as an adult have changed in response to the invention of dairying, so the genes for flushing your brain with oxytocin have probably changed in response to population growth, urbanisation and trading – people have become oxytocin-junkies far more than many other animals.
Moreover, finding the underlying physiology of trust does little to explain why some human societies are much better at generating trust than others. As a broad generalisation, the more people trust each other in a society, the more prosperous that society is, and trust growth seems to precede income growth. This can be measured by a combination of questionnaires and experiments – leaving a wallet on the street and seeing if it is returned, for instance. Or asking people, in their native tongue, ‘generally speaking, would you say that most people can be trusted, or that you cannot be too careful in dealing with people?’ By these measures, Norway is heaving with trust (65 per cent trust each other) and wealthy, while Peru is wallowing in mistrust (5 per cent trust each other) and poor. ‘A 15% increase in the proportion of people in a country who think others are trustworthy,’ says Paul Zak, ‘raises income per person by 1% per year for every year thereafter.’ This is most unlikely to be because Norwegians have more oxytocin receptors in their brains than Peruvians, but it does suggest that Norwegian society is better designed to elicit the trust systems than Peruvian.
It is not at all clear what comes first: the trust instinct or trade. It is most unlikely that the oxytocin system fortuitously mutated into a sensitive form, which then enabled human beings to develop trading. Much more plausibly, human beings began tentatively to trade, capturing the benefits of comparative advantage and collective brains, which in turn encouraged natural selection to favour mutant forms of the human mind that were especially capable of trust and empathy – and even then to do so cautiously and suspiciously. I shall be amazed if the genetics of the oxytocin system do not show evidence of having changed rapidly and recently in response to the invention of trade, by gene-culture co-evolution.
The shadow of the future
A trillion generations of unbroken parental generosity stand behind a bargain with your mother. A