Money, depletion, and prosociality in the dictator game.

We study the effects of ego depletion, a manipulation which consumes self-control resources, on social preferences in a dictator game. Depleted dictators give considerably less than non-depleted dictators and hence exhibit strong preferences for selfish allocation. In contrast to earlier studies, participants were explicitly paid for completing the egodepletion task (with either a flat rate or strictly performance-based payment). We studied the dynamics of decisions by repeating the dictator game 12 times (anonymously). Depleted dictators start with much lower offers than non-depleted ones, but, strikingly, offers decrease in time for both groups, and more rapidly so for non-depleted dictators. We conclude that, while depleted dictators neglect fairness motives from the very first decision on, non-depleted dictators initially resist the tendency to act selfishly, but eventually become depleted or learn to act selfishly. Hence, prosocial behavior may be short-lived, and ego depletion uncovers the default tendencies for selfishness earlier.