Reacting differently to adverse ties promotes cooperation in social networks

Cooperation is essential in every society, but puzzling from an evolutionary perspective. Here, we address the role of behavioral differences - ubiquitous among Humans - on the evolution of cooperation. We study a model in which individuals can either cooperate or defect. They engage in a social dilemma of cooperation, interacting along the edges of a complex network. The structure of the network changes in time, as individuals regularly engage in new interactions while abandoning old ones. Social interactions may be long or brief, depending on the individuals involved. When dissatisfied, some individuals will try to break contact as soon as possible, whereas others will remain in touch. We show that cooperation blooms - and society as a whole benefits - the larger the behavioral diversity in responding to unwanted interactions. These results support the idea that diversity, on a grand scale, is instrumental in shaping us as the most sophisticated cooperating entities on this planet. Mathematically, we show that taking explicitly into account the feedback between co-evolving mechanisms - here network topology and individual strategy and behavior - profoundly affects the outcome of those processes, a result which has widespread consequences in many problems of natural and social sciences.