Don’t believe “willpower is like a muscle; use it a while and it’s gone”
Grade AMedium benefitTimeFreeLittle timeNo willpower
The popular claim is: do one self-control task first, then you break more easily afterward, so conserve willpower. Twenty-three labs and 2141 people redid the experiment under the same protocol; the result was almost zero. Stop explaining yourself with “willpower is used up today,” and don’t pay for courses that teach you to stockpile willpower.
- Cost
- No money. All that needs changing is one claim.
- Benefit
- A multi-lab preregistered replication had 23 laboratories and 2141 participants. They redid the sequential-task paradigm under Sripada and colleagues’ standardized protocol: first a depleting self-control task, then a second task that needs self-control. Pooled results showed a very small ego-depletion effect, and the 95% credible interval included 0 (d = 0.04, 95% CI −0.07 to 0.15). The authors discuss whether the “self-control is a limited resource” model still stands. Another similarly preregistered redo, 36 labs and 3531 people, found effect size d = 0.06 — again too small to count.
- Notes
- What to reject is the model “self-control is a resource that can be used up,” not “people get tired.” Too little sleep and working too long lower efficiency — that is separate; handle it with the sleep and hours items in Section 3. What has randomized-trial support is changing the environment and the written plan — see Section 4, Item 10 (move what you should not touch farther away) and Section 4, Item 1 (write “at what time, where, when X happens, do Y”). Fixing what you wear and what you eat is still worth doing because it costs almost nothing. What it saves is those few minutes and a few rounds of indecision, not willpower; don’t expect it to make afternoon judgment better. Other items in this section count money; this one counts time and energy — the two are not converted.
Sources · 2
- Hagger MS, Chatzisarantis NLD, Alberts H, et al. (2016). A Multilab Preregistered Replication of the Ego-Depletion Effect. Perspectives on Psychological Science, 11(4), 546–573. doi.org/10.1177/1745691616652873
- Vohs et al. (2021). A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect. Psychological Science. doi.org/10.1177/0956797621989733