Blurred Lines: How the Collectivism Norm Operates Through Perceived Group Diversity to Boost or Harm Group Performance in Himalayan Mountain Climbing

We develop and test a theory that reconciles contradictions in how collectivistic norms influence group performance. We draw on the perceived diversity literature to hypothesize that collectivistic norms cause group members to “blur” demographic differences, resulting in a shared perception that group members are more similar to one another than they actually are. Whether this benefits or harms group performance depends on the level of objective diversity in the group and the relevance of the perceived diversity attribute for accomplishing the group’s task. For conjunctive tasks, the group’s performance is determined by its weakest member, and high levels of cohesion are needed. Our theory suggests that collectivism benefits group conjunctive performance when objective national diversity is high by blurring divisive relational differences but has no effect in groups with low objective national diversity. In contrast, for disjunctive tasks, the group’s performance is determined by its best member, and we predict that collectivism harms group disjunctive performance when objective expertness diversity is high by blurring differences in task-relevant expertness, but has no effect in groups with low objective expertness diversity. We find support for our theory in two studies, including an archival study of 5,214 Himalayan climbing groups and a laboratory experiment assessing 356 groups. Our results show that collectivism has benefits and detriments for diverse groups, and that these contradictory effects can be understood by identifying how the collectivistic blurring of perceived group diversity helps or hurts groups based on the type of tasks on which they are working