Mechanisms of self-control failure: motivation and limited resources.

Research has found that individuals who are lower in self-control strength because of previous self-control exertions perform more poorly on subsequent tests of self-control. The present studies suggest that this effect may be moderated by motivation. In particular, depletion and motivation jointly determine self-control performance. Individuals who were depleted and believed that the task would help others (Experiment 1) or believed that their efforts could benefit them (Experiment 2) performed better on a subsequent test of self-control than individuals who were depleted and lower in motivation. The results of Experiment 3 replicated these findings and suggested that depletion only affects performance on tasks that require self-control; tasks that are difficult but do not require self-control are immune to the effects of depletion. Hence, depleted individuals may compensate for their lack of self-control resources when sufficiently motivated. The results may help explain the nature of self-control strength.