Figure 2

Shifting weight from individual payoffs to average payoffs of nearest neighbors promotes the evolution of cooperation, but it is important whether the shift entails the average payoffs of neighbors on the host network (α) or the average payoffs of neighbors on the other, interdependent network (β).

Depicted are contour plots showing the stationary fraction of cooperators ρ_C in dependence on both α and β for r/G = 0.4 (left), 0.7 (middle) and 0.8 (right). Increasing α at any given β promotes the evolution of cooperation. The same is true vice versa, only that the positive effect depends much more on α and r/G, thus highlighting the importance of an intact network reciprocity on each individual network for increasing β to work. Details of Monte Carlo simulations are the same as described in Fig. 1.