Henri Tajfel's minimal group paradigm experiments in the early 1970s revealed something remarkable about the human tendency to form social groups. Participants who were randomly assigned to arbitrary categories, divided ostensibly by aesthetic preference between paintings by Klee or Kandinsky, or literally by coin flip, showed reliable in-group favoritism within minutes. They allocated more resources to members of their own category than to members of the other category, even when this was economically irrational, even when they did not know who the individual recipients were, and even when their own allocations did not benefit themselves. No shared history, no interaction, no common fate, just a categorical label, was sufficient to produce discriminatory behavior.
The Theory and Its Mechanisms
Tajfel and Turner developed social identity theory to explain these findings. The theory proposes that social group memberships form part of the self-concept, the social identity, and that people are motivated to maintain a positive social identity by ensuring that their groups compare favorably to relevant out-groups. This motivation, social identity maintenance, produces a characteristic set of cognitive and behavioral responses. In-group members are evaluated more favorably. Out-group members are evaluated less favorably and perceived as more homogeneous. Comparisons with out-groups are constructed or selected to favor the in-group. And when unfavorable comparisons are unavoidable, people may leave the group psychologically by disidentifying from it, enhance the group's status through collective action, or reframe the dimension of comparison to favor their group.
Social identity theory generated a second theoretical development, self-categorization theory, which specifies the cognitive processes through which people categorize themselves and others into groups and describes how the salience of different identities shifts across contexts. The same person may identify primarily as a professional, a parent, a member of an ethnic group, a political partisan, or a sports fan depending on which contextual features make which identity relevant. The identity that is currently salient shapes perception, judgment, and behavior in predictable ways that the theory specifies.
Real-World Applications
Social identity theory illuminates an extensive range of real-world phenomena. Organizational identity affects employee behavior and organizational commitment in ways that management research has extensively documented. Political identity shapes information processing in ways that make factual correction ineffective when facts challenge group-associated beliefs, a finding with significant implications for public communication and democratic deliberation. Ethnic and racial identity dynamics explain patterns of intergroup discrimination, prejudice, and conflict that rational self-interest models cannot adequately account for, and they point toward the specific conditions under which intergroup contact reduces prejudice.
The contact hypothesis, the proposition that intergroup contact reduces prejudice, was extended and qualified by Pettigrew and Tropp's meta-analysis showing that contact works best when it occurs under conditions of equal status, common goals, institutional support, and opportunities for personal acquaintance. Social identity theory explains why: contact under these conditions reduces the salience of group categories and facilitates the personalized, cross-cutting relationships that undermine the categorical thinking on which prejudice depends. Contact under conditions that activate and reinforce group distinctiveness, in which group membership is highly salient and groups interact as groups rather than as individuals, can reinforce prejudice rather than reduce it.
Identity in Educational Settings
The implications of social identity theory for educational settings are substantial. Stereotype threat, the performance impairment that occurs when individuals from groups subject to negative stereotypes are aware that their performance may confirm the stereotype, is a direct consequence of social identity processes. The awareness that one's performance might reflect on one's group activates identity-protective responses that consume cognitive resources and disrupt performance. Interventions that reduce stereotype threat, by affirming a valued identity before a challenging task, by normalizing difficulty as a common experience rather than evidence of group membership, or by explicitly disconfirming the stereotype's relevance to the task, produce meaningful performance improvements in well-designed experimental studies.
