Henri Tajfel's minimal group paradigm experiments in the early 1970s revealed something remarkable: people could be randomly assigned to arbitrary groups , divided by coin flip, or ostensibly by aesthetic preference , and within minutes would show in group favoritism, allocating more resources to fellow group members than to out group members, and evaluating in group members more positively. No history, no shared goals, no meaningful social bond , just a categorical distinction. This finding launched social identity theory, one of the most generative frameworks in social psychology.
From minimal groups to real world dynamics
Social identity theory proposes that social group memberships form part of the self concept, and that people are motivated to maintain positive social identities by ensuring their groups compare favorably to relevant out groups. This motivation , social identity maintenance , helps explain a wide range of intergroup phenomena: in group favoritism in hiring and promotion decisions, the persistence of stereotypes that maintain group status hierarchies, the difficulty of changing attitudes through information alone when attitude change threatens group identity, and the power of identity threats to mobilize collective action. It also explains why intergroup contact reduces prejudice only under specific conditions , conditions that create personalized, equal status interaction rather than encounters that activate and reinforce group categories.
