THE SUCCESS OF COOPERATIVE STRATEGIES IN THE ITERATED PRISONER'S DILEMMA AND THE CHICKEN GAME

Abstra t. The prisoner's dilemma has evolved into a standard game for analyzing the su ess of ooperative strategies in repeated games. With the aim of investigating the behavior of strategies in some alternative games we analyzed the out ome of iterated games for both the prisoner's dilemma and the hi ken game. In the hi ken game, mutual defe tion is punished more strongly than in the prisoner's dilemma, and yields the lowest tness. We also ran our analyses under dierent levels of noise. The results reveal a striking dieren e in the out ome between the games. Iterated hi ken game needed more generations to nd a winning strategy. It also favored ni e, forgiving strategies able to forgive a defe tion from an opponent. In parti ular the well-known strategy tit-for-tat has a poor su essrate under noisy onditions. The hi ken game onditions may be relatively ommon in other s ien es, and therefore we suggest that this game should re eive more interest as a ooperative game from resear hers within omputer s ien e. Key words. Game theory, prisoner's dilemma, hi ken game, noise, tit-for-tat 1. Introdu tion. Within omputer s ien e, biology, so ial and e onomi s ien es the issue of ooperation between individuals in an evolutionary ontext is widely dis ussed. An evolutionary ontext means some oni t of interest between the parti ipants preferrably modeled in a game theoreti al ontext using oni ting games. A simple, but frequently used, game model is between two parti ipants ea h with two hoi es, either to ooperate or to defe t (a 2 ∗ 2 matrix game) played on e or repeated. In multi agent systems iterated games have be om