Ego Depletion: Theory and Evidence

Self-control all too often fails. Despite people’s best intentions and considerable negative outcomes, people often find themselves at the losing end of resisting temptation, combating urges, and changing their behavior. One reason for these failures may be that exerting self-control depletes a limited resource (ego depletion) that is necessary for the success of self-control. Hence, after exerting self-control, individuals are less able resist temptations, fight urges, or stop a behavior that results in a loss of self-control. This chapter reviews the evidence for this theory in a wide variety of domains and examines what behaviors appear to deplete ego strength and how depletion affects behavior. A comprehensive theory that examines how depletion operates is put forth and used to examine some factors that might moderate the depletion effect.