ABSTRACT
Social sciences analyse cooperation based on a static and simultaneous game: the prisoner's dilemma (PD). This chapter presents the problems related to the PD. It analyses the properties of cooperative behaviour and the process that is at its origin. An analytical representation of reciprocity under the angle of the Tit For Tat strategy confirms, under certain conditions, the stabilizing properties of cooperation. The chapter introduces "reciprocity" in order to study its characteristics in the context of the rational choice model. It discusses two methodological concepts: the rational choice model, where agents are supposed to be rational, and an alternative framework where the assumption of rationality is relaxed: the evolutionary game theory approach. The evolutionary approach is probabilistic and induces, in certain cases, nonlinearity. Therefore, it is sometimes impossible to use deductive mathematics to determine the consequences of a given model.
