Search

Making a promise involves a fairly fast yet complicated assessment of potential outcomes. Outside of the immediate consideration of the benefit of keeping the promise versus the cost of breaking it, one also needs to assess whether to pay a cost for keeping it or obtaining a gain for breaking it. Often this decision is compounded with the interpersonal relations and social closeness of the interaction. However, the impact of social closeness on our decisions in the context of keeping promises has not been explored. As our interactions occur with people with whom we share differing degrees of social closeness, it is fundamental to understand how these different social contexts can impact our decisions. We investigated whether the decision to keep or break a promise can be modulated by the degree of social closeness between the promisor and promisee. The participants in the experiment played a trust game with three partners: a computer, a stranger, or a friend. The game consisted of making a promise to their partners and subsequently deciding between paying a cost to keep it or obtaining a benefit for breaking it. The experiment allowed us to independently evaluate the effect that promises and social closeness have on the decision to cooperate. Using Bayesian Hierarchical Modeling, we found that, in accordance to our prediction, as social closeness increases, the probability of breaking the promise decreases. We also found that participants could not be assigned into honest or dishonest categories, as the decision to keep promises was modulated by latent commitment. Our findings suggest that the benefits of breaking a promise are evaluated depending on the familiarity of the affected person and that high social closeness might add more utility to follow through on a promise.