The Success of Cooperative Strategies in the Iterated Prisoner's Dilemma and the Chicken Game


Bengt Carlsson
K. Ingemar Jönsson


The prisoner's dilemma has evolved into a standard game for analyzing
the success of cooperative strategies in repeated games. With the
aim of investigating the behavior of strategies in some alternative
games we analyzed the outcome of iterated games for both the prisoner's
dilemma and the chicken game. In the chicken game, mutual defection
is punished more strongly than in the prisoner's dilemma, and yields
the lowest fitness. We also ran our analyses under different levels
of noise. The results reveal a striking difference in the outcome
between the games. Iterated chicken game needed more generations to
find a winning strategy. It also favored nice, forgiving strategies
able to forgive a defection from an opponent. In particular the well-known
strategy tit-for-tat has a poor successrate under noisy conditions.
The chicken game conditions may be relatively common in other sciences,
and therefore we suggest that this game should receive more interest
as a cooperative game from researchers within computer science.


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