Effects of Degree on Cooperation in Evolutionary Prisoner's Dilemma Games on Structured Populations

We focus on the effects of individuals' degrees on spontaneous cooperation. By investigating evolutionary PDGs on random networks with two distinct degrees, we find some resonance-type behaviors of the cooperator frequency with the variation of degree. We also find that increasing hub's degree actually disfavors the cooperation though the heterogeneity in degree can enhance cooperation in the population.