Components of reward in social dilemmas.

A social dilemma (Dawes, 1980) may be defined as a situation in which a collection of individuals is faced with a conflict between maximizing selfish interests and maximizing collective interests. The dilemma is based on the fact that if all choose to maximize selfish interests, all are worse off than if all choose to maximize collective interests. In a decomposed social dilemma (Pruitt, 1967), the outcomes are divided into two components: one component is based on one's own choice and the second component is based on the choices made by the others. Using 3-person decomposed games, two types of incentives were contrasted: a positive incentive (bonus) for cooperative choices and a negative incentive (penalty) for noncooperative choices. Two experiments were conducted using male college students. The results of both experiments showed that the positive incentive evoked a higher level of cooperation than the negative incentive. The results are discussed in terms of nonadditive utility components, Pruitt's motivational interpretation, and Kelley and Thibaut's (1978) theory of interdependence.