A Theoretical Analysis of How Multiple Leadership and Flattened Status Structures Affect Cooperation in Task Groups

Status hierarchies have been shown to emerge in small, collectively-oriented task groups and to structure cooperative social interaction in them. In sociology, the argument that status hierarchies can facilitate cooperation in small groups has been theoretically validated by evolutionary models and empirically confirmed by laboratory/field experiments. Although there is a robust tendency toward the emergence of status hierarchies in small task groups, we can consider the rare cases in which a status structure emerges (i.e., status differences emerge) within a task group but no single member of the group is ranked higher in status than every other group member. In other words, we can consider groups with two or more leaders who are higher in status than others in the group but who are equal in status to each other. We conduct an evolutionary game-theoretic analysis to determine the capacity of status behavior to promote cooperation in these uncommon cases. Our analytical results, corroborated by agent-based simulations, reveal that while multi-leadership structures can sustain cooperation, they do so less effectively than single-leader hierarchies. Factors such as group size and assortative mixing significantly influence the emergence of cooperation in multi-leader groups. We also identify the trade-offs between single-leader and multi-leader hierarchies in fostering cooperation, demonstrating how hierarchical clarity impacts the willingness to cooperate. Put together, our model offers a generalized framework for understanding how status hierarchies influence the emergence of cooperation in collectively oriented task groups.