Bargaining and fairness.

The idea that human morality might be the product of evolution is not popular. The reason is partly that the moral principles that actually govern our day-to-day behavior have been idealized in a way that makes a natural origin seem impossible. This paper puts the case for a more down-to-earth assessment of human morality by arguing that the evolution of our sense of fairness can be traced to the practicalities of food-sharing. When animals share food, they can be seen as enjoying the fruits of an implicit bargain to ensure each other against hunger. The implications of this observation are explored using the tools of game theory. The arguments lead to a structure for fair bargains that closely resembles the structure proposed by John Rawls, the leading moral philosopher of the last century.