The Rational Optimist (P.S.)

by Matt Ridley

The lesson of the ultimatum game and hundreds like it is that again and again people emerge from such experiments as nicer than you think. But the even more surprising lesson is that the more people are immersed in the collective brain of the modern commercial world, the more generous they are. As the economist Herb Gintis puts it, ‘societies that use markets extensively develop a culture of co-operation, fairness and respect for the individual’. His evidence comes from a fascinating study in which people in fifteen mostly small-scale tribal societies were enticed to play the Ultimatum Game. Those societies with the least experience of dealing with outsiders were the most hard-hearted, ungenerous and narrowly ‘rational’. Machiguenga slash-and-burn farmers from the Amazon most often offered just 15 per cent of the sum to their co-subjects, and in all but one cases, the second player accepted. Likewise, a Hadza hunter-gatherer from Tanzania usually makes a very small offer and experiences few rejections. On the other hand, players from those societies that are most integrated into modern markets, such as the Orma nomads of Kenya or the Achuar subsistence gardeners of Ecuador, will usually offer half the money just as a Western undergraduate would. The whale-hunting Lamalera of the island of Lembata in Indonesia, who need to coordinate large teams of strangers on hunts, offer on average 58 per cent – as if investing the windfall in acquiring new obligations. Much the same hap...