The Effects of Cooperation and Competition on Ingroup‐Outgroup Bias¹

A matrix game format was employed in a 2 × 2 design to study the effects of within group cooperation and competition under conditions of success and failure on subjects' subsequent treatment of own group and outgroup persons. Subjects in two‐person groups either succeeded or failed at a cooperative or competitive game and then awarded points (worth money) to themselves, their partner, and two other people. A review of the relevant literature suggested that ingroup‐outgroup bias would be greater after successful competition than after unsuccessful competition. The results supported this hypothesis. It was also found that subjects in the Cooperation‐Failure condition displayed greater ingroup‐outgroup bias than subjects in the Cooperation‐Success condition. A qualification of the previous research supporting a positive relationship between group cohesiveness and ingroup‐outgroup bias was suggested on the basis of the results.