Psychological mechanisms for individual recognition- and anonymous-societies in humans and other animals

To understand the nature and evolution of different kinds of societies, we must characterize the psychological mechanisms members use to identify who belongs. Across both individual recognition- and anonymous-societies, these range from physiological responses to individuals up to powerful conceptual representations of the group that license generalization and novel predictions. Sketching these mechanisms helps us understand the transition from the individual recognition societies of our ape ancestors to uniquely human forms of anonymous society.