Heterogeneity of link weight and the evolution of cooperation

• We confirm that the heterogeneity of link weight promotes evolution of cooperation.
• We identify two key mechanisms whereby heterogeneity enhances cooperation.
• The identified mechanisms are those for the spread/maintenance of cooperation.
• We derive the conditions under which the above-mentioned mechanisms can work.

In this paper, we investigate the effect of heterogeneity of link weight, heterogeneity of the frequency or amount of interactions among individuals, on the evolution of cooperation. Based on an analysis of the evolutionary prisoner’s dilemma game on a weighted one-dimensional lattice network with intra-individual heterogeneity, we confirm that moderate level of link-weight heterogeneity can facilitate cooperation. Furthermore, we identify two key mechanisms by which link-weight heterogeneity promotes the evolution of cooperation: mechanisms for spread and maintenance of cooperation. We also derive the corresponding conditions under which the mechanisms can work through evolutionary dynamics.