Evolutionary Prisoner’s Dilemma Game in Flocks

Abstract

We investigate the effect of mobility on the evolution of cooperation in a flock model, where each player moves on the two-dimensional plane with the same absolute velocity. At each time step every player plays the prisoner’s dilemma game and aligns moving direction with its neighbors, who are chosen according to distances between them in the two-dimensional space. Experimental results have shown that with unconditional cooperation or defection, cooperation can be maintained in mobile players even for high velocities, as local interactions among players are enhanced by the expansion of neighborhood. However, the movement of players can only be offset within a certain range of temptation b, while outside this range a rapid decrease of cooperators will appear in the population because too many neighbors are involved.