Can You Boost Your Self-Control?

Scientists debate whether we lose the ability to resist temptation over time, or just no longer want to.

As far as examples of willpower go, one of the most impressive you’ll
ever find is the “incredible Buddha boy“chronicled in GQ a few years back by George Saunders. The boy had been meditating under a tree for seven months, evidently without food or water. It was a display of self-control so haunting that readers couldn’t help but wonder how such a person could exist while the rest of us find it so hard–really, impossible–to rise from the couch and go to the gym, or read a book, or in some cases just reach the remote.


The prevailing scientific wisdom says that people operate with a finite supply of self-control. In an insta-classic study from the 1990s, psychologists found that test participants who pushed themselves to suppress a thought for six minutes subsequently gave up more quickly on an unsolvable anagram than those who came into the puzzle fresh. Exerting self-control on an initial task evidently drained people of persistence for a second one. Willpower seemed to tire a bit every time we use it, a little like a muscle.

The idea that self-control might be a limited resource is tremendously appealing. It simultaneously suggests why our willpower often fails us (we’ve used too much of it recently) and how we can conserve it (strengthen the muscle with self-control tasks). Little surprise that a 2011 book on this science–Willpower, co-authored by psychologist Roy Baumeister and journalist John Tierney–became a bestseller. The practical implications for people in both their professional and personal lives are as obvious as they are endless.

But Newton’s apple aside, few scientific insights emerge on the scene in perfect form. While the depletion model of self-control has been validated by more than a hundred empirical studies, it remains rife with limitations and rough edges. In an upcoming paper for Trends in Cognitive Science, a research team led by Michael Inzlicht of the University of Toronto not only points out some of the theory’s shortcomings but proposes an alternative: iIt’s not that our willpower weakens, it’s that our motivations change.

“From this standpoint, self-control failure is less about resource depletion and more about the motivated switching of task priorities from ‘have-to’ to ‘want-to’ goals,” write Inzlicht and company. Put another way: Perhaps flipping on the television after a long day of work isn’t a sign that we’ve used up all our willpower for the day. Perhaps it reflects a natural desire to balance the grueling labor of life with gratifying leisure.

Let’s step back a bit and look at a couple problems with the resource theory. A big one is that it’s difficult to measure our “supply” of willpower in any direct way. Behavioral scientists have identified glucose as a potential physiological marker of self-control, and in some cases, willpower does appear to ebb and flow with glucose levels. In one test, for instance, people who consumed a glucose drink found their self-control replenished. But other similar studies have tried to confirm glucose as the source of our willpower, and failed.

There’s also the basic observation that sometimes people can sustain high levels of self-control over extended periods of time–all energy drinks aside. If self-control is truly a limited physiological resource, our varying psychic states should have little to do with it, yet in test after test, it does. One study found that people who believed willpower was unlimited showed no depletion on self-control tasks; another found the same persistence in people who had simply prayed beforehand. Perhaps such examples are the exception to the resource rule, or perhaps they’re a sign that it should be rewritten.


Inzlicht and his collaborators suggest revising the theory to focus more on motivation. It’s not that we lose the ability to resist temptation after a long stretch of willful exertion, they argue. It’s that we no longer want to. The difference may seem semantic, but it carries empirical weight. A 2003 study depleted test participants of willpower with a tough initial task, then measured how they did on a second one. Those who believed the task would help others or themselves–in other words, those who were motivated to do it–performed better than those who did not.

So maybe self-control can’t be explained by physiological resources alone. Sure, we sink into the couch after a long day of work. Is that because we’re no longer capable of labor, or rather because we much prefer by that point to bask in leisure? Inzlicht and company argue for the latter, largely on the strength of adaptive reasoning: any human need to attain rewards through work must be partnered with the equally powerful need to enjoy those rewards.

“Although self-control does seem to have a refractory period”–that low point on the willpower meter–“it is caused by shifting priorities and the increasing averseness of cognitive work,” the researchers conclude. “It is not caused by some hard cap on control.”

The motivation theory has flaws of its own. Reverse engineered, it suggests that people who flip their days, beginning with leisure and ending with labor, will be equally productive. That’s a tough sell. Still, if it’s true that self-control hinges more on motivation than on resources, the practical implications shift, too. Businesses might invest more in motivational tactics, or perhaps be inclined to grant more breaks and vacations. We’ll be watching eagerly as the science of self-control sorts itself out–from the couch, of course.


About the author

Eric Jaffe is an editor at CityLab, where he writes about transportation, history, and behavioral science, among other topics, through the lens of urban life. He's also the author of The King's Best Highway (2010) and A Curious Madness (2014)