The idea is that willpower is depleted through use ("ego depletion"), but the research seems to be divided on whether this is actually true. Some recent studies

The idea is that willpower is depleted through use ("ego depletion"), but the research seems to be divided on whether this is actually true. Some recent studies have found "a growing body of evidence suggesting ego-depletion is not a reliable phenomenon." http://nymag.com/scienceofus/2016/03/psychologys-favorite-theory-about-willpower-may-be-totally-wrong.html http://nymag.com/scienceofus/2016/03/psychologys-favorite-th...