Competitiveness mediates the link between personality and group performance.

The performance of individuals within groups, and of groups as units, is the product of immediate goal structures and personality differences pertinent to those goals among group members. A level-of-analysis approach linked the dimension of agreeableness to situated competitiveness and task performance in group settings. Hypotheses were (a) individual differences in self-rated and other-rated competitiveness are related (inversely) to the Big Five dimension of agreeableness, (b) immediately situated promotive and contrient goal structures influence self-ratings of competitiveness, (c) immediate goal structures differentially activate competitiveness to affect task performance in groups, and (d) agreeableness effects on task performance are partially mediated by competitiveness. Structural equation modeling corroborated hypotheses about the links among agreeableness, competitiveness, and task performance.