How Does In-Group Observation Influence Intergroup Cooperation? Experimental Evidence from Papua New Guinea

Abstract

This paper addresses the key challenge of how to promote intergroup cooperation. Using a lab-in-the-field experiment in Bougainville, Papua New Guinea, we study individuals’ willingness to cooperate with another person in an incentivized social dilemma game. In a between-subjects design, we vary (i) whether individuals interact with a member of their own or another community, and (ii) whether individuals are observed by a key in-group member or not. We find that when individuals are not observed, they are less likely to cooperate with members of other communities. Yet, observation by an in-group member increases the share of people who cooperate with members of other communities from 17 percent to 70 percent, such that there is no in-group bias in cooperation when participants are observed. We relate the results to a shared understanding among the participants that intergroup cooperation is socially desirable. Our findings suggest that communities, organizations, and policymakers may leverage in-group observation to improve intergroup cooperation.