Indirect Reciprocity for Mitigating Intergroup Hostility: A Vignette Experiment and an Agent-based Model on Intergroup Relations between Mainland Chinese and Taiwanese.

Social scientists have proposed myriad solutions for mitigating intergroup conflicts. While the literature, such as studies on intergroup contact theory, focuses on intergroup relations, we argue that it is important not to ignore intragroup relations that may benefit or undermine the improvement of intergroup relations at the same time. In this paper, we investigate a typology of eight mechanisms for the behavior of intergroup and intragroup relations. Specifically, we focused on interactions in a triad consisting of an actor paired up with two alters—one ingroup and one outgroup. The triadic network enabled us to theorize and test how intergroup and intragroup relations coevolve. We conducted a vignette experiment to test the intergroup relationship between mainland Chinese and Taiwanese. We found strong evidence for one mechanism for improving intergroup hostility: indirect reciprocity—people rewarded the outgroup for behaving friendly to their ingroup peers. Using agent-based simulation, we predicted that the triadic effect found in the one-shot experiment can continuously improve and stabilize intergroup relations over time. [ABSTRACT FROM AUTHOR]