Don’t believe that “willpower is like a muscle that runs out after use”

No cost at all. All that needs changing is the way we talk about it.

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.

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. https://doi.org/10.1177/1745691616652873；Vohs et al. (2021). A Multisite Preregistered Paradigmatic Test of the Ego-Depletion Effect. Psychological Science. https://doi.org/10.1177/0956797621989733

What’s being refuted is the notion that self‑control is a consumable resource, not that people can become fatigued. Lack of sleep or prolonged effort does reduce performance, but that falls under the guidelines on sleep and working hours in Section 3. The only evidence‑based actions are environmental tweaks and simple wording changes, as described in Section 4, items 10 (“move unwanted items out of reach”) and 1 (“write down exactly when, where and what you’ll do”). Fixing routine choices such as clothing and diet is still worthwhile because it costs almost nothing. It saves minutes and mental effort, not “willpower”; don’t expect it to improve your judgment later in the day. While other items in this section deal with monetary costs, this one concerns time and mental energy, which aren’t interchangeable.