Hipsters and the cool: A game theoretic analysis of identity expression, trends, and fads.

Abstract

Cultural trends and popularity cycles can be observed all around us, yet our theories of social influence and identity expression do not explain what perpetuates these complex, often unpredictable social dynamics. We propose a theory of social identity expression based on the opposing, but not mutually exclusive, motives to conform and to be unique among one’s neighbors in a social network. We find empirical evidence for both conformity and uniqueness motives in an analysis of the popularity of given names. Generalizing across forms of identity expression, we then model the social dynamics that arise from these motives. We find that the dynamics typically enter random walks or stochastic limit cycles rather than converging to a static equilibrium. The dynamics also exhibit momentum, preserve diversity, and usually produce more conformity between neighbors, in line with empirical stylized facts. We also prove that without social network structure or, alternatively, without the uniqueness motive, reasonable adaptive dynamics would necessarily converge to equilibrium. Thus, we show that nuanced psychological assumptions (recognizing preferences for uniqueness along with conformity) and realistic social network structure are both critical to our account of the emergence of complex, unpredictable cultural trends.