Effects of punishment in a mobile population playing the prisoner's dilemma game.
We deal with a system of prisoner's dilemma players undergoing continuous motion in a two-dimensional plane. In contrast to previous work, we introduce altruistic punishment after the game. We find punishing only a few of the cooperator-defector interactions is enough to lead the system to a cooperative state in environments where otherwise defection would take over the population. This happens even with soft nonsocial punishment (where both cooperators and defectors punish other players, a behavior observed in many human populations). For high enough mobilities or temptations to defect, low rates of social punishment can no longer avoid the breakdown of cooperation.
Complex Systems Lab, Departament de Física, Universitat de Girona, E-17071 Girona, Catalonia, Spain. daniel.rodriguez@udg.edu
Daniel R
DR
Amor
Joaquim
J
Fort
D000533:Altruism; D005075:Biological Evolution; D003299:Cooperative Behavior; D005716:Game Theory; D006801:Humans; D011678:Punishment