When it's fair to share

Abstract

A striking feature of human societies, compared with those of other primates, is the egalitarian sharing of resources in many situations. However, both children and chimpanzees share resources less equitably after receiving a 'windfall'. A behavioural study of reactions to windfall payments, in which children received toys and chimps food, reveals a tendency for children as young as three to share windfalls more fairly if they were earned by a team member through a collaborative effort. This contradicts the common assumption that egalitarian tendencies emerge during the school years, at six or seven, when children learn social norms of equality. Chimps do not favour equity, whether or not windfalls were received through collaboration. The modern human tendency to distribute resources more equitably among the larger group may have roots in the sharing of spoils after joint efforts.