Baumeister's experiments and the strength model
In Baumeister and colleagues' (1998) experiment, participants who had to resist freshly baked cookies and eat radishes instead gave up sooner on unsolvable puzzles than those who did not. The researchers interpreted this as reduced persistence because the strength used to resist temptation had been depleted, and called it ego depletion. Muraven and Baumeister (2000) set out the strength model, in which self-control, like a muscle, tires with use but grows stronger with practice. The idea spread to research on self-control theory in other fields and to studies of dieting, spending and learning.
The role of beliefs and motivation
Hagger and colleagues (2010) reported a moderate effect in a meta-analysis of dozens of early studies. Yet doubts grew about whether the effect was really due to resource loss. Job and colleagues (2010) showed that the effect was weak among people who believed willpower is not easily exhausted. Inzlicht and Schmeichel (2012) proposed an alternative model in which, rather than resources running out, motivation and attention shift from what one has to do to what one wants to do after an initial task. This connects to motivation-centered perspectives such as self-determination theory.
The replication debate
Carter and McCullough (2014) found that correcting for publication bias, the tendency for null results to go unpublished, could make the ego depletion effect largely disappear. Hagger and colleagues (2016) then ran a preregistered protocol across 23 laboratories and found an overall effect close to zero. The result became an emblematic case of psychology's replication crisis and spurred the spread of preregistration and large collaborative studies. Some argue that the tasks used failed to induce depletion, and follow-up studies with stronger manipulations mean the debate continues.
FAQ
- What is ego depletion in simple terms?
- The idea that after you have to hold yourself back once, you have less self-control for the next task, as though willpower were a limited fuel.
- Has ego depletion been confirmed?
- Many early studies reported the effect, but a large 2016 preregistered replication found almost none, so it is now regarded as highly contested.
Sources reviewed: 2026-10-26
References
- 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(5), 1252–1265. The original ego depletion experiments.
- Muraven, M., & Baumeister, R. F. (2000). Self-regulation and depletion of limited resources: Does self-control resemble a muscle? Psychological Bulletin, 126(2), 247–259. Sets out the strength (muscle) model of self-control.
- Hagger, M. S., Wood, C., Stiff, C., & Chatzisarantis, N. L. D. (2010). Ego depletion and the strength model of self-control: A meta-analysis. Psychological Bulletin, 136(4), 495–525. An early meta-analysis reporting a moderate effect.
- Job, V., Dweck, C. S., & Walton, G. M. (2010). Ego depletion—Is it all in your head? Implicit theories about willpower affect self-regulation. Psychological Science, 21(11), 1686–1693. Shows beliefs about willpower moderate depletion.
- Inzlicht, M., & Schmeichel, B. J. (2012). What is ego depletion? Toward a mechanistic revision of the resource model of self-control. Perspectives on Psychological Science, 7(5), 450–463. Proposes a motivation-and-attention alternative to the resource model.
- Carter, E. C., & McCullough, M. E. (2014). Publication bias and the limited strength model of self-control: Has the evidence for ego depletion been overestimated? Frontiers in Psychology, 5, 823. Shows the effect shrinks after correcting for publication bias.
- Hagger, M. S., Chatzisarantis, N. L. D., Alberts, H., Anggono, C. O., Batailler, C., Birt, A. R., ... Zwienenberg, M. (2016). A multilab preregistered replication of the ego-depletion effect. Perspectives on Psychological Science, 11(4), 546–573. A 23-lab preregistered replication finding a near-zero effect.