Ego Depletion

Ego Depletion Definition

Ego depletion refers to the loss of a personal resource (and associated breakdown in performance) due to the previous exertion of self-control or other effortful and willful acts of the self. Ego depletion may be especially important in understanding why self-control fails and what the processes are that underlie self-control.

Ego DepletionThe model of ego depletion suggests that individuals have a fixed amount of resource to exert self-control or perform other effortful and willful acts of the self. This resource, called ego strength, is required for any and all self-directed efforts (in particular, self-control and making choices that are relevant to the self). This ego strength is consumed or depleted in the process of self-control, however. In addition, this ego strength is recovered slowly, so that it remains depleted for some time after the exertion itself. Thus, the process of exerting self-control or making choices reduces the amount of ego strength available for future self-control efforts. Moreover, the success of self-control depends on ego strength: When ego strength is depleted, self-control is more likely to fail. Hence, individuals whose ego strength has been depleted through the previous exertion of the self’s will are more likely to suffer a loss of self-control, because the success of self-control depends on having enough strength to fight off the temptation. In short, the exertion of self-control can lead to poorer self-control subsequently, through the exhaustion of self-control strength, a process known as ego depletion.

Evidence for Ego Depletion

Although a direct measurement of individual’s ego strength is not yet possible, scientists can investigate the effects of ego depletion by examining self-control performance. In particular, researchers have focused on how exerting self-control affects subsequent self-control performance. Consistent with the process outlined in the previous section, individuals perform more poorly on a task that requires self-control after exerting self-control, as compared to individuals who worked on an equally frustrating, arousing, and unpleasant task that did not require self-control. For instance, in one experiment, individuals who were asked not to eat freshly made chocolate chip cookies (a highly tempting food that requires a great deal of self-control not to eat) subsequently quit working on a difficult puzzle sooner than individuals who were asked not to eat radishes (a less tempting food that requires only a little self-control not to eat). Despite the differences in final self-control performance, the groups did not differ in mood or arousal; the differences in persistence on the frustrating puzzle appeared to be the result of how much self-control was required by the initial task.

Subsequent research illustrates the importance of ego strength in self-control. Underage drinkers were asked to record their alcohol intake on a palm-top computer for more than 2 weeks. They also reported their moods, urge to drink, and self-control demands on this computer. On days that they reported greater self-control demands than average (and hence were more ego depleted), they were more likely to drink alcohol, consumed more alcohol when they did drink, and became more intoxicated. Most important, when they were ego depleted, these drinkers reported consuming more alcohol than they intended. In other words, they had trouble controlling their alcohol intake when ego depleted. Additional analyses indicated that self-control demands did not increase the urge to drink, but instead undermined their ability to self-regulate.

Ego Depletion Importance and Implications

Ego depletion may help explain why self-control breaks down, despite a person’s best intentions. If a person’s level of ego strength is depleted, he or she may find it difficult to resist temptations, as demonstrated in the research on underage drinkers. Because many important behaviors require self-control, the process of ego depletion can have broad ranging effects, from increased criminal behavior and prejudice to picking fights with significant others and even a decline in intellectual performance. Likewise, everyone has many demands on his or her ego strength throughout the day. Besides resisting temptations, research has found that making personally difficult choices, controlling moods and thoughts, trying to make a good impression, and even ignoring someone depletes ego strength. Indeed, there is evidence that individuals are more likely to suffer a breakdown in self-control in the evening as compared to the morning because of the amount of self-control that everyone has to exert throughout the day.

Because of the many demands on our ego strength and the importance of self-control, self-management of ego strength is key. Individuals may decide what self-control tasks are important (and hence will deplete ego strength on) and which are less important. Both external and internal motivators likely shape this decision. This means that the conservation of ego strength is critical and can help explain the difference between individuals and situations in self-control outcomes.

It is also important to realize that exerting self-control may lead to eventual increases in ego strength. In the same way that lifting a heavy weight fatigues a muscle and leads to weakness until the person has had a chance to rest, exerting self-control appears to deplete ego strength. However, much as lifting weights leads to greater strength and increased resistance to fatigue with rest and proper training, the judicious regular exertion of self-control may lead to better self-control performance in the long run.


  1. Baumeister, R. F., Bratslavsky, E., Muraven, M., & Tice, D. M. (1998). Ego-depletion: Is the active self a limited resource? Journal of Personality and Social Psychology, 74, 1252-1265.
  2. Muraven, M., & Baumeister, R. F. (2000). Self-regulation and depletion of limited resources: Does self-control resemble a muscle? Psychological Bulletin, 126, 247-259.
  3. Muraven, M., Collins, R. L., Shiftman, S., & Paty, J. A. (2005). Daily fluctuations in self-control demands and alcohol intake. Psychology of Addictive Behaviors, 19, 140-147.