Why some behaviors spread while others don't: A laboratory simulation of dialect contact.

The question of how behavioral variants compete and propagate is of primary importance to the study of cultural evolution; with respect to language, it is also an important focus of the field of sociolinguistics. Variant propagation can occur by neutral means-akin to drift in biological evolution-or through selection, whereby individuals are biased in what variants they adopt. An important bias concerns social meaning, and sociolinguistic theory distinguishes between variants that are primarily associated with a particular social group (such as working-class people or Texans) and variants primarily associated with a perceived trait of the group (such as toughness). In the former case, variants are hypothesized to propagate neutrally; in the latter case, provided the trait is socially relevant to adopters, variants are hypothesized to be subject to selection and to propagate more readily. To test this hypothesis we conducted an experimental study in which groups of four participants played a game that involved instant messaging in an artificial "alien language" with two dialects. Each player was assigned to one of two alien species, the weaker Wiwos or the tougher Burls. The social meaning of one feature of the Burl dialect was manipulated, and the results strongly supported the hypothesis: Variants from the Burl dialect were used by Wiwos in all conditions, but when associated primarily with "tougher aliens", the rate of adoption was significantly greater than when they were associated primarily with "Burls". When toughness was made irrelevant to the game, the effect of association disappeared, emphasizing the importance of social relevance in the propagation of behavioral variants.