When Would Intergroup Contact be a Blessing? an Evolutionary Simulation Model

Intergroup contact theory—one of the landmark paradigms of modern social psychology—argues that social contacts across group boundary help mitigate prejudices toward an outgroup person. A meta-study over decades of empirical research recently confirm the hypothesis (Pettigrew and Tropp 2006). Despite a strong empirical support, the underlying mechanisms that facilitate the effect remains unclear. We propose an evolutionary model to fill the theoretical gap. Actors of different social groups play a trust game against one another in the model. They use different strategies to decide whether or not to trust an ingroup or outgroup partner. We incorporate network transitivity is the formation of a strategy: A trusts B because A trusts C and C and B are of the same group. We present an agent-based simulation to show the circumstances under which intergroup contact leads to intergroup trust (or even global trust) that was found in empirical social psychological research.