 Note that, in the new coordination game (which was created by the existence of the cooperative norm), the payoffs are quite different from those of the original prisoner’s dilemma. Thus there are two equilibria: if both players follow the cooperative norm they will play an optimal equilibrium and get (B,B), whereas if they both choose to defect they will get the suboptimal outcome (S,S). Players’ payoffs in the new coordination game differ from the original payoffs because their preferences and beliefs will reflect the existence of the norm. More specifically, if a player knows that a cooperative norm exists and has the right kind of expectations, then she will have a preference to conform to the norm in a situation in which she can choose to cooperate or to defect. In the new game generated by the norm’s existence, choosing to defect when others cooperate is not a good choice anymore (T,W). To understand why, let us look more closely to the preferences and expectations that underlie the conditional choice to conform to a social norm.