The evolution of generosity: Welcome, stranger | The Economist
THE extraordinary success of Homo sapiens is a result of four things: intelligence, language, an ability to manipulate objects dexterously in order to make tools, and co-operation. Over the decades the anthropological spotlight has shifted from one to another of these as the prime mover of the package, and thus the fundament of the human condition. At the moment co-operation is the most fashionable subject of investigation. In particular, why are humans so willing to collaborate with unrelated strangers, even to the point of risking being cheated by people whose characters they cannot possibly know?