Quantity versus uncertainty: When winning one prize is better than winning two

We predicted that a state of uncertainty would prolong a positive mood, but that people would not anticipate this when making affective forecasts. In Study 1, participants learned that they had won one prize (certain condition), two prizes (two-gift condition), or one of two prizes (uncertain condition). People in the uncertain condition were in a positive mood longer than people in the other two conditions. In Study 2, forecaster participants underestimated the benefits of uncertainty and overestimated the benefits of quantity (getting two gifts instead of one). Under some circumstances, and contrary to people’s predictions, uncertainty can prolong positive mood, and winning one prize under a state of uncertainty can bring more short-term pleasure than winning two prizes.