Even explicitly random group assignment produces discrimination stronger than interpersonal similarity

Evidence

Billig and Tajfel (1973) have found the same results even when the assignment to groups was made explicitly random. This eliminated the similarity on the performance criterion within the in-group as an alternative explanation of the results. An explicitly random classification into groups proved in this study to be a more potent determinant of discrimination than perceived interpersonal similarities and dissimilarities not associated with categorization into groups. Billig (1973), Brewer and Silver (1978), Locksley, Ortiz and Hepburn (1980), and Turner, Sachder and Hogg (1983) have all replicated this finding that even explicitly arbitrary social categorizations are sufficient for discrimination, and Allen and Wilder (1975) have provided additional evidence for the importance of group classification compared to similarities between people without such classification. — John T. Jost and Jim Sidanius, Political Psychology, 2707

Categorization

• XREF: connects to: Anticipatory loss of group standing drives outgroup discrimination — Brenda Major and Alison Blodorn and Gregory Major Blascovich, The threat of increasing diversity: Why…, 14; Identity alignment requires perceived sufficiency of similarity rather than actual sameness — Mary Bucholtz and Kira Hall, Identity and Interaction: A…, 75