Evolution of emotions on networks leads to the evolution of cooperation in social dilemmas

摘要

We show that the resolution of social dilemmas in random graphs and scale-free networks is facilitated bynimitating not the strategy of better-performing players but, rather, their emotions. We assume sympathy andnenvy to be the two emotions that determine the strategy of each player in any given interaction, and we definenthem as the probabilities of cooperating with players having a lower and a higher payoff, respectively. Startingnwith a population where all possible combinations of the two emotions are available, the evolutionary processnleads to a spontaneous fixation to a single emotional profile that is eventually adopted by all players. However,nthis emotional profile depends not only on the payoffs but also on the heterogeneity of the interaction network.nHomogeneous networks, such as lattices and regular random graphs, lead to fixations that are characterized bynhigh sympathy and high envy, while heterogeneous networks lead to low or modest sympathy but also low envy.nOur results thus suggest that public emotions and the propensity to cooperate at large depend, and are in factndetermined by, the properties of the interaction network.