 The story may unfold somewhat differently in what Skyrms calls an “attenuated” PD, where the payoffs are, let us say, 2.01, 2, 1.98, and 0. (We might think of this as the “Just Don't Be a Sucker” game.) Here, as before, the cooperators quickly learn not to choose defectors as partners. The defectors get roughly the same payoffs whether they choose cooperators or defectors as partners. Since they rapidly cease being chosen by cooperators, however, their returns from interactions with cooperators will be less than returns from defectors and they will soon limit their choices to other defectors. (It is important to understand here that the learning algorithm that determines the probability I will interact with agent \(\ba\) depends on total returns from interacting with \(\ba\)(or total recent returns from interacting with \(\ba\)) rather than average returns from interacting with \(\ba\).) So in the attenuated game we end up with perfect association: defectors play defectors and cooperators play cooperators. Since the reward payoff slightly exceeds the punishment payoff, the cooperators again do better than the defectors.