Coevolution of Cultural Groups and Ingroup Favoritism

• Published in: Science (American Association for the Advancement of Science) Vol. 321; no. 5897; pp. 1844 - 1849
• Main Authors: Efferson, Charles, Lalive, Rafael, Fehr, Ernst
• Format: Journal Article
• Language: English
• Published: Washington, DC American Association for the Advancement of Science 26.09.2008; The American Association for the Advancement of Science
• Subjects: Biological and medical sciences; Causal covariation; coevolution; Coordinate systems; Coordination games; Cultural Evolution; Cultural groups; Cultural identity; Death; Evolution; Favoritism; Fundamental and applied biological sciences. Psychology; Games, Experimental; Group dynamics; Group Processes; Humans; Prejudice; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Social Behavior; Social Environment; Social Identification; Social interaction; Social interactions. Communication. Group processes; Social psychology; T tests; taste; Unobservables; We they distinction; Social environment; Human; Social preference; Social interaction; Social group; Biological evolution; Cultural environment; Ingroup; Coevolution; Experimental study; Intergroup relation
• ISSN: 0036-8075; 1095-9203; 1095-9203
• DOI: 10.1126/science.1155805

Cultural boundaries have often been the basis for discrimination, nationalism, religious wars, and genocide. Little is known, however, about how cultural groups form or the evolutionary forces behind group affiliation and ingroup favoritism. Hence, we examine these forces experimentally and show that arbitrary symbolic markers, though initially meaningless, evolve to play a key role in cultural group formation and ingroup favoritism because they enable a population of heterogeneous individuals to solve important coordination problems. This process requires that individuals differ in some critical but unobservable way and that their markers be freely and flexibly chosen. If these conditions are met, markers become accurate predictors of behavior. The resulting social environment includes strong incentives to bias interactions toward others with the same marker, and subjects accordingly show strong ingroup favoritism. When markers do not acquire meaning as accurate predictors of behavior, players show a markedly reduced taste for ingroup favoritism. Our results support the prominent evolutionary hypothesis that cultural processes can reshape the selective pressures facing individuals and so favor the evolution of behavioral traits not previously advantaged.