The Folk Theorems in the Framework of Evolution and Cooperation.

Proceeding from the latest version of the Folk Theorems, the present paper shows that "natural" evolution of behavior in repeated games in human populations is a very unstable process which may be easily manipulated by outside forces. Any feasible and individually rational payoff of the game may be converted in the globally stable outcome by arbitrary small perturbation of the payoff functions in the repeated game. We show that this result also holds for a trembling-hand perturbation of the game, and prove a new version of the Folk theorem for this case. This conclusion is in contrast to Axelrod (1984), Sigmund and Nowak (1992) and some other researches of evolution of behavior in the repeated Prisoner's dilemma. We discuss the reasons of the difference in the results.