Non-human primates forage mostly to feed themselves. Since this is not true of human foragers, a sexual division of labour and regular food-sharing have been nominated as the evolutionary keys to a distinctively human way of life (e.g. Washburn and Lancaster 1968). The evident economic co-operation among men and women is used to justify the view that families or larger social groups are units of common interest with members deployed to meet group needs. Here I provide theoretical and empirical justification for the contrary view that the interests of individuals, and the way these vary with sex, age and ecology, can better explain human foraging patterns and the social strategies of which they are part.