How the Distribution of Member Expectations Influences Cooperation and Competition in Groups: A Social Relations Model Analysis of Social Dilemmas

Group outcomes are difficult to model and predict using individual-level metrics. We use shared cognition concepts and the social relations model to predict cooperative group outcomes in two social dilemmas to test whether social projection or consensus among group members would best predict cooperation. Group-level variance components derived from the social relations model were used as indices of social projection and consensus. Groups played five rounds of two social dilemmas and predicted their partners’ behavior on the following round. Results demonstrate that participants expect other group members to respond to the situation like the participant will and that shared expectations predict less competitive group behavior, but only when group members’ expectations have little to no variance. This article demonstrates the utility of the social relations model in predicting group-level outcomes from individual inputs, as well as providing novel findings regarding the complex effects of shared expectations on collective outcomes.