Abstract

The debate over group selection shows no signs of abating. If existent, group selection is likely to have significantly reinforced prosocial and altruistic behavior. This article is theoretical and argues that there have been some major lacunae in the debate as concerns humans. The traits that are most uniquely and universally human—such as prolonged rearing of dependent offspring, the family, large-scale, tribal networks, and cultural-linguistic diversity and exclusivity—have been largely overlooked. These most salient and mutually reinforcing human specifics vastly increased individuals' stake in and commitment to ancestral tribal groups. Tribal members were in the same boat, and risked massive fitness loss if it were sunk. This suggests that group selection existed and was much stronger among humans than among any other animal species.