Figure 2.
Stationary density of cooperators ρC in dependence of T2 = T, as obtained on the square lattice using S2 = 0.5 (left panel, cutting across the harmony and the snowdrift game) and S2 = −0.5 (right panel, cutting across the stag-hunt and the prisoner’s dilemma game). The curves represent results obtained for different values of τ, as indicated in the legend. For comparison, the evolutionary outcome obtained with the classical version of the game is also shown (uniform). It can be observed that in the snowdrift game longer periods results in a higher average cooperation level, while in the stag-hunt game more frequent seasonal changes have a similarly positive effect (the same holds for the prisoner’s dilemma game, not shown).