You Don't Actually Run Out Of Willpower, But Here's Why You Think You Do

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If you like reading about pop psychology, you've probably heard about the phenomenon of "ego depletion": that is, if you exert willpower early in the day, like fighting the urge to yell at a rude client, you won't have any left over later for, say, resisting the temptation to have ice cream for dinner. It turns out that all of that is one big myth. Willpower is not a finite resource.


What The Science Says

In 1998, husband-and-wife psychologists Roy Baumeister and Dianne Tice performed a study into self-control. They placed fresh-baked cookies next to a bowl of radishes, then asked half of a group of volunteers to sit in the room unattended. Half of the volunteers were told to eat only the radishes, and half were allowed to eat the cookies. Next, they were given a (secretly unsolvable) puzzle to solve. The people who ate the radishes quit faster than those who ate cookies, suggesting that the willpower it took to not eat the cookies was no longer available to stick it out on the puzzle task.

More than a decade and a half later, a meta-analysis (that is, a study that uses data from multiple studies to come to one big conclusion) published in the Journal of Experimental Psychology found something worrying. Most of the studies of ego depletion with small sample sizes showed huge effects, when you should expect to find at least a few with no effects. That pointed to publication bias, or the tendency for journals to only publish studies that show a relationship between two things—few people want to read a study that says two things don't have anything to do with each other, even if that study is important. So psychologist Martin Hagger spearheaded an effort to re-do the original study in a bunch of different labs. The results? "We found that the ego-depletion effect was roughly zero," Hagger told LiveScience.

What's Really Going On

If willpower isn't finite, then why is it so hard to exert it when you're staring down a bowl of candy in the Curiosity kitchen after writing an article on willpower at 6:15 in the evening? (Asking for a friend). Experts have a few theories.

Michael Inzlict at the University of Toronto says that you can think of self-control more as something driven by motivation than by something that runs out — that is, it's the foot on the gas pedal, not the fuel in the tank. Just like you might lose the motivation to put your dirty clothes in the hamper on Thursday when you were fastidious about it on Monday, you might just not feel motivated to use willpower if you've done it a lot already — all that writing earned you that candy, right?

Another theory deals with the way people frame willpower. A Stanford study showed that if people thought willpower was a limited resource, they showed signs of so-called ego depletion. But if they didn't think willpower was finite, they showed no such effect. So technically, by reading about how willpower isn't finite, you're freeing yourself from the effects of ego depletion. You're welcome!

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