Cooperation Under Oath : A Case for Context-Dependent Preferences

We examine in an experiment whether a solemn oath to cooperation mediates defection in a prisoners’ dilemma among those making a commitment and those whom the commitment is being made to. We explore which of the two internal drivers of behavior, preferences or beliefs, is activated to promote a change in behavior. We find that (1) oath-takers increase cooperation, but oath-receivers do not, and that (2) strategies of oath-takers significantly change from selfish to reciprocal. Our findings are inconsistent with the hypothesis that an oath acts through beliefs as a coordination device, but consistent with the hypothesis that a statement of intent generates cooperative dispositions. We provide evidence of an instance of context-dependent preferences