Ego depletion

Ego depletion is the controversial idea that self-control or willpower draws upon a limited pool of mental resources that can be used up (with the word "ego" used in the psychoanalytic sense rather than the colloquial sense). When the energy for mental activity is low, self-control is typically impaired, which would be considered a state of ego depletion. In particular, experiencing a state of ego depletion impairs the ability to control oneself later on. A depleting task requiring self-control can have a hindering effect on a subsequent self-control task, even if the tasks are seemingly unrelated. Self-control plays a valuable role in the functioning of the self on both individualistic and interpersonal levels. Ego depletion is therefore a critical topic in experimental psychology, specifically social psychology, because it is a mechanism that contributes to the understanding of the processes of human self-control. There have both been studies to support and to question the validity of ego-depletion as a theory.

Some meta analyses and studies have questioned the size and existence of the ego depletion effect. The ultimate validity and conclusions of those later studies is not universally agreed upon. Martin Hagger and Nikos Chatzisrantis, whose 2010 meta-analysis seemed to support the existence of the ego depletion effect, subsequently performed a pre-registered 23 lab replication study which did not find an ego-depletion effect.