The Evolution of Anxiety and Social Exclusion

To support the hypothesis that anxiety is a species-typical adaptation to prevent social exclusion, several facts about group living must be explicated: (1) groups provide unusual concentrations of particular social resources, some of which aid survival (e.g., protection from nonspecific aggressors) but many of which aid reproduction (e.g., pool of potential mates); (2) it is not groups in general that people want to be members of but particular groups such as kin groups, those that have power, and those that are similar to oneself; (3) the events that lead to group exclusion (e.g., mate poaching, stealing, cheating, murder) are particular and nonarbitrary, and they typically decrease the reproductive success of particular group members who instigate exclusion; and (4) in addition to reproductive benefits, group living carries costs—an intensification of conflict and competition. Discussion focuses on the standards that must be met before considering anxiety a species-typical adaptation to prevent social exclusion.