The social psychologist Roy F. Baumeister coined the term ego depletion in the 1990s to describe this phenomenon. He contended that we possess a limited conceptual resource called ego strength, which is depleted through the day by our various efforts at self-regulation—resisting temptations, making trade-offs, inhibiting our desires, controlling our thoughts and statements, adhering to other people’s rules. People in this state, said Baumeister, are ego depleted.
