Strong leaders don’t cheat: an evolutionary appraisal of population heterogeneity and leadership

Coordination and cooperation are crucial features of many natural and artificial systems. Among the many mechanisms that have been proposed to support their emergence, leadership can play an important role. In human and other animal groups, inter-individual differences can lead to the emergence of successful leaders, who assume their role thanks to their physical or cognitive capabilities that grant them some influence over the behavior of their peers. Hence, heterogeneity in a population appears as a key element for successful leaders. Here, we present an evolutionary game theoretic model to study the effect of leadership and heterogeneity on cooperative behavior and examine the relationships between the two. We show that the presence of a leader can promote the evolution of cooperation. Moreover, we find that, when there is the possibility for a leader to emerge in the group, heterogeneity benefits cooperation. In our model, players cooperate when they are more likely to become leaders, and defect otherwise. In other words, strong leaders do not defect, but act as exemplar of prosocial behavior that, when followed, lead to full cooperation.