"In-Group Love" and "Out-Group Hate" in Repeated Interaction Between Groups

Costly individual participation in intergroup conflict can be motivated by "in-group love"-a cooperative motivation to help the in-group, by "out-group hate"-an aggressive or competitive motivation to hurt the out-group, or both. This study employed a recently developed game paradigm (Halevy, Bornstein, & Sagiv, 2008) designed specifically to distinguish between these two motives. The game was played repeatedly between two groups with three players in each group. In addition, we manipulated the payoff structure of the interaction that preceded the game such that half of the groups experienced peaceful coexistence and the other half experienced heightened conflict prior to the game. Enabling group members to express in-group love independently of out-group hate significantly reduced intergroup conflict. Group members strongly preferred to cooperate within their group, rather than to compete against the out-group for relative standing, even in the condition in which the repeated game was preceded by conflict. Although both "in-group love" and "out-group hate" somewhat diminished as the game continued (as players became more selfish), choices indicative of the former motivation were significantly more frequent than choices indicative of the latter throughout the interaction. We discuss the implications of these findings for conflict resolution.