A CAS for Finding the Best Strategy for Prisoner’s Dilemma

Prisoner’s Dilemma (PD) is a typical type of non-zero-sum game in game theory. Since first raised by Merrill Flood and Melvin Dresher in 1950’s, a lot of research has been done in this area, especially after Robert Axelrod introduced the concept of the iterated prisoner’s dilemma in his book “The Evolution of Cooperation” in 1984. In this project, we have explored a complex adaptive system (CAS) designed for finding the “best” strategy for playing PD. The winning strategy depends on the starting conditions. After running the system for a while, an interesting pattern emerges. First, there is an initial consolidation of starting strategies. Second, one (and the same) strategy emerges as the favorite one in the middle of the run. In the end, however, either Tit-for-Tat or “History-Matters” wins the “minds” of the agents. Both of those strategies are of the “cooperate” flavor.