The emergence of segregation: from observable markers to group specific norms

Abstract

Observable social traits determine how we interact in society and remain pervasive even in our globalized world. While a popular hypothesis states that they may help promote cooperation, the alternative explanation that they facilitate coordination has gained ground in recent years. Here we explore this framework and present a model that investigates the role of ethnic markers in coordination games. We consider fixed markers characterizing agents that use reinforcement learning to update their strategies in the game. For a wide range of parameters, we observe the emergence of a collective equilibrium in which markers play an assorting role. However, if individuals are too conformists or greedy, markers fail to shape social interactions. These results extend and complement previous work focused on agent imitation and show that reinforcement learning is a good candidate to explain many instances of ethnic markers.