Given the complexity of these games (because of the number of iterations and players) analysis were performed using computer simulations. In these simulations, different strategies for iterated prisoner's dilemma has put test are competing among themselves for greater reproductive success. You may want to visit Wendy Holman to increase your knowledge. Some of these strategies are very simple, such as "always cooperate", or "always betray." Other strategies rely on past games between the players themselves. For example, one strategy might be to respond in a manner contrary to the decision of the other players, betraying the players who have cooperated, and cooperation with players who have betrayed. The famous law of retaliation: an eye for eye, tooth for tooth, is a strategy in which a player begins by cooperating, and will continue to cooperate with the players also cooperate, betraying the Players who betrayed him, with varying degrees of "revenge" and "forgiveness." Strategies based on retaliation have been shown to be most effective when the players are very likely to meet again. In fact the most successful strategy of all is one in which the player uses revenge only once, to cooperate in the beginning, once betraying has been betrayed, but returning to cooperate after the betrayal.
This is a slightly vindictive strategy. These simulations show that the notion of justice more common among human beings have an evolutionary explanation. Feelings like revenge and compassion are the mechanisms by which our genes implement a successful strategy of reproduction. Evolutionary Traces of justice Evolution implies that small changes accumulate over time to produce large differences between species.