Discrimination in the minimal group paradigm: Social identity or self-interest?

Social identity theory (SIT) proposes that discrimination reflects competition for a positive social identity. In contrast, the behavioral interaction model (BIM) proposes that self-interest and interdependence of fate are at the root of discrimination. Using the minimal group paradigm, 94 undergraduates were randomly categorized as group members in a 2 (Interdependence: autonomous/interdependent) x 2 (In-group Identification: low/high) factorial design. Before distributing resources, autonomous participants were told they would personally receive the maximum number of points in the experiment independently of others' allocations. Interdependent participants received points depending on allocations made by in-group and out-group others. Contrary to BIM, autonomous individuals discriminated as much as interdependent respondents, and discrimination was unrelated to expectation of in-group reciprocity. In line with SIT, high in-group identifiers discriminated more than low in-group identifiers.