Age-related vitality of players promotes the evolution of cooperation in the spatial prisoner’s dilemma game

Within most real biological or social systems, age plays an important role in the vitality of individuals. For instance, individuals become more and more weak with age, while young individuals may prosper even under poor living conditions. In this paper, we find that aging as a coevolutionary process promotes cooperation more effectively than quenched heterogeneous distributions of age. By studying the average age of defectors and cooperators along the boundaries separating the domains of the two strategies, we reveal the significance of coevolutionary rules for the successful evolution of cooperation amongst selfish and unrelated individuals.