Group Conflict and Cooperation: Their Social Psychology

Sherif argues that intergroup conflict and cooperation are determined by the functional relationship between groups—specifically, whether their goals are mutually exclusive or mutually dependent. When groups compete for goals that only one can attain, in-group solidarity and out-group hostility rise together. When they face superordinate goals that require joint effort, hostility can be reversed. This rejects explanations that locate the causes of conflict in individual aggressiveness, authoritarian personalities, or inherent ethnocentrism. Sherif's framework treats group formation, norm emergence, and intergroup attitudes as one interconnected process, with the Robbers Cave experiments serving as the central empirical demonstration of the full cycle from group formation through conflict to cooperation.

Group Conflict and Cooperation (1966) is the theoretical synthesis that the 1961 Robbers Cave monograph empirically grounded. The 1961 book, published by University Book Exchange, reported the summer camp study in detail; the 1966 volume steps back to place those findings within a general account of group formation, norms, and intergroup relations. It also draws on earlier research programs, including the autokinetic norm-formation studies and the 1949 and 1953 precursor camp studies. Readers who want the data should consult the 1961 book; readers who want the framework should consult the 1966 volume. The two are complementary, and neither is a substitute for the other.

The book consolidates realistic group conflict theory and the concept of superordinate goals, along with Sherif's earlier constructs of group norms, reference groups, and ego-involvements. Realistic conflict theory holds that intergroup prejudice and discrimination arise from perceived competition over scarce resources, status, or power. Superordinate goals are objectives that groups cannot achieve alone and that therefore require cooperation. These concepts are used today in conflict-resolution practice, peace-building interventions, organizational behavior, and research on ethnic and political conflict. The framework also directly influenced social identity theory, though Tajfel and Turner extended it by showing that mere categorization can produce in-group bias without resource competition—a claim Sherif's theory would not predict.

Social identity theory, developed by Henri Tajfel and John Turner in the 1970s, argues that mere categorization into groups is sufficient to produce in-group favoritism, even without competition for resources. Sherif's realistic conflict theory holds that competition over scarce goals is necessary for hostility to emerge; categorization alone, in his framework, produces group formation but not necessarily hostility. The two frameworks are often taught as complementary rather than rivalrous: Sherif explains competition-driven conflict and its resolution through superordinate goals, while social identity theory explains the cognitive and motivational roots of group preference. The distinction matters because it predicts different conditions for intervention—Sherif points to restructuring goal relationships, social identity theory to managing categorization and status.

A frequent misreading treats the book as claiming that contact between hostile groups is sufficient to reduce conflict. Sherif found the opposite in the Robbers Cave study: bringing the groups together for shared meals and entertainment intensified hostility rather than reducing it. Only superordinate goals requiring cooperative effort improved relations. The book therefore rejects the simplest version of the contact hypothesis, according to which proximity and interaction breed tolerance. What matters is the goal structure—whether groups must depend on each other to achieve outcomes neither can reach alone. This distinction is often lost when the book is cited only for its demonstration of conflict rather than for its equal emphasis on the conditions under which cooperation can be restored.

The Robbers Cave study and its precursors have been criticized on several grounds. The participant sample was homogeneous—white, middle-class, Protestant boys—limiting generalizability to diverse real-world conflicts. Researchers actively manipulated events, including staging provocations and supplying materials for vandalism, which complicates claims that hostility emerged spontaneously. Participants and parents were not fully informed and were deceived about the study's purpose. Gina Perry's archival investigation, published in The Lost Boys (2018), found that two earlier iterations of the experiment had failed to produce the desired conflict and were not reported in the published account. These issues reflect mid-century norms but raise questions about the study's ecological validity.