Ethnocentric biases arise even from trivial or random group assignments

Evidence

Allport’s ideas about social categorization and recategorization at higher levels of inclusiveness foreshadowed many of the theoretical and empirical developments of importance to contemporary thinking about prejudice and prejudice reduction. … In the process of categorizing people into groups, people typically classify themselves into one of the social categories and out of the others. Because of the centrality of the self in social perception, this distinction has a profound influence on evaluations, cognitions, and behavior. Perhaps one reason why ethnocentrism is so prevalent is because these biases operate even when the basis for the categorization is quite trivial, as when group identity is assigned randomly in laboratory experiments. — , Rudman, Laurie A - On the Nature of…, 545

Categorization

• XREF: Connects to classic minimal group paradigm results (Tajfel) and the vault’s existing claims about ingroup favoritism and contact theory’s categorization basis.
• corroborated: 3 independent passages support this claim — , Rudman, Laurie A - On the Nature of…, 545