Justice and discrimination between minimal groups: the limits of equity.

Intergroup discrimination in the minimal group paradigm (MGP), which is usually invoked in support of social identity theory (SIT), seems to contradict every principle of social justice. A contradiction to equity theory (ET), however, exists only if one is committed to the transferability of ET from intragroup to intergroup relations. But even in that case one could explain intergroup discrimination in the MGP as a reaction to anticipated discrimination by out-group members and as therefore being in accordance with ET. Two experiments were devised to test SIT against ET as an explanation of intergroup discrimination in the MGP. In the first experiment the introduction of 'interindividual mutuality' into the experimental condition was found to significantly reduce intergroup discrimination almost down to equality as compared with a control condition which resembles the usual MGP procedure. In a second experiment first assumed distribution behaviour of out-group members as well as subjects' own intended distribution behaviour were assessed and second anticipation of fairness and discrimination was manipulated. Although most of the subjects assumed that they would be treated fairly by out-group members and likewise intended to be fair themselves, manipulation of anticipated out-group behaviour was found to lead to significant intergroup discrimination regardless of whether discrimination or fairness was anticipated. Implications of these findings for SIT and ET are discussed.