You would go to the gym tonight — you totally would. It’s just that you spent all day resisting temptation at work, avoiding Gchat and other distractions to focus on getting stuff done. Your stores of willpower have been depleted.
This is the thinking that lies behind the psychological concept of “ego depletion,” a term that was popularized in the 1990s with a hugely influential series of experiments led by Roy F. Baumeister. The theory goes like this: Willpower is a finite resource. If you use too much of it on something in the morning like turning down a doughnut, you’ll have less of it in the afternoon — which means it’s not your fault you ate an entire sleeve of Thin Mints. You’d already used up your supply of willpower, so you couldn’t help it. It’s science.
Ego depletion is even the core reason behind President Barack Obama’s identical suits, or Mark Zuckerberg’s trademark gray T-shirts. “I’m in this really lucky position where I get to wake up every day and help serve more than a billion people,” Zuckerberg said in 2014. “And I’d feel I’m not doing my job if I spent any of my energy on things that are silly or frivolous about my life.”
Again, energy — here, really a stand-in for the idea of willpower, or the capacity to just make yourself do stuff — is characterized as something you “spend,” which means there’s a limited amount of it. And yet newer evidence is questioning this long-held theory of ego depletion — which, in a way, suggests something rather optimistic. If willpower isn’t finite, maybe that means it’s limitless.
The YouTube series Bite Size Psych took on this subject earlier this week, explaining that original experiment from 1998 that inspired much of this research. (That paper, by the way, has been cited more than 3,000 times, according to Google Scholar.) In that study, “participants had to either resist eating radishes — which, presumably, no one had problems with — or resist eating chocolate, a much more draining task,” the video’s narrator explains. “Afterwards, both groups were given an unsolvable problem. Those who had their willpower depleted, by resisting chocolate, gave up twice as fast as those who had to resist radishes.”
And yet in several very recent studies — one published in the fall of 2014 and the other published just last month, both in the journal PLOS ONE — the evidence just didn’t hold up. At this year’s annual meeting of the Society for Personality and Social Psychology, there was an entire session devoted to the potential dismantling of this favored idea.
These are issues for psychologists to sort out among themselves. But for you, it may not even really matter that much whether ego depletion is “real” or not. What matters is how you think about your own amount of willpower. A very intriguing direction of research is finding the power of a person’s own beliefs about willpower may be what makes the difference here. When people believe their willpower is limitless, they’re more likely to go after personal goals, they’re less likely to burn out, and they’re happier. In a sense, when people believe their willpower is limitless, it turns out to be true.