in: Behavior, Character, Featured

• Last updated: July 5, 2023

Willpower Part II: How Your Willpower Is Depleted

Willpower man with Teddy Roosevelt on shoulder illustration.

In the first post of this three-part series, we offered a general outline of the nature of willpower, noting that it is a real mental energy which regulates your thoughts, emotions, impulses, and performance control by keeping in check desires and behaviors at odds with your values and long-term goals.

We then compared the battle between your willpower and those unwanted desires to Al Bundy and Theodore Roosevelt sitting on your shoulders in the roles of the classic angel and devil.

We ended by saying that the winner of that battle depended on the strength of TR relative to Al at a given moment. And today we will explore what affects that balance and just how your willpower is weakened, a fascinating subject in and of itself, and one that is a necessary precursor for understanding how to then conserve, strengthen, and harness this vital force.

Willpower: A Finite Resource

In addition to the TR/Bundy image, it is also helpful to think of your willpower like a muscle. All of these qualities of your muscles also apply to your willpower:

  • Your muscles become weak and flabby through disuse and a lack of exercise.
  • In order to build the strength of your muscles in the long-term, you must exhaust them in the short-term.
  • While you can build the strength of your muscles over time, on any given day when you walk into the gym, your muscles have a finite amount of strength–there’s an absolute max weight you can lift before your muscles reach failure.
  • If you exhaust your muscles with one exercise, you’ll have less strength and endurance on the next exercise because your muscles will be fatigued. Your muscles need time to recover before they can be fresh again for your next workout.
We’ll come back to the first two points in our final post. Today we’re going to concentrate on those last two, exploring the fact that on any given day you have a finite supply of willpower, and that when you use part of that supply for one thing, you have less of it for others.

How Is Willpower Depleted?

Willpower ego depletion tank getting lower illustration.

Your supply of willpower is depleted in two ways.

First, by exercising self-control.

Every time you have a desire to do something that conflicts with accepted social norms or with your values and goals, and your willpower overrides that desire and keeps you on track, part of your willpower supply gets depleted. The stronger the desire and the harder it is to resist, the more of your willpower fuel is burned up in the struggle.

The need for self-control kicks in more times a day than you probably realize. In one study, participants were given beepers that randomly went off seven times a day and asked to record what they were experiencing when they heard the beep. Researchers found that at any given moment, 50% of the participants were feeling a desire right when the beeper went off–whether to eat, sleep, have sex, or surf the web–and another quarter of them had experienced a desire in the few minutes preceding the beep. All in all, the researchers found that on average people spend four hours a day resisting desires.

If that number seems high, think of all the desires you may have had in the last five minutes:

I want to eat that leftover pizza. But I’m not really hungry, I’m just bored. Bob just posted a ridiculous and false partisan article on Facebook. I really want to leave a comment telling him about all the errors in the piece, but that will just stir things up for no reason. I shouldn’t be on Facebook anyway, I need to get back to work. I really want to put my head down on the desk and take a nap….

The four hours you spend resisting desires each day doesn’t even include the second thing that saps your willpower: making decisions.

As with exercising your self-control, the harder the decision, the more your willpower supply gets drained. But even a back-to-back series of small and enjoyable decisions will eat up some of your willpower.

While simply shopping around and weighing different choices diminishes your willpower, it’s the moment when you lock in that choice and cast the die that gobbles it up the most. When you lock in one choice, you must reject other possibilities, and humans hate narrowing their options.

The diminishment of your willpower supply through the making of decisions and the exercise of self-control has been named “ego depletion” (for Freud’s term for the self) by foremost willpower expert, psychologist Roy F. Baumeister.

Your Brain on Ego Depletion

So what’s going on in your brain when your willpower energy gets depleted?

When you’re suffering from ego depletion, your brain’s anterior cingulate cortex—the part of your brain that detects a mismatch between what you intended to do and what you’re actually doing—slows down. When your willpower tank is full, and you start getting off track, the ACC is quick to jump in with a, “Hey, hey, hey, what do you think you’re doing? Get your hand off that mouse and put your eyes back on the textbook. We have a final in 2 hours!” But when your willpower muscle is fatigued, your anterior cingulate cortex reacts with a delayed and muted alarm.  The more of your willpower that’s been depleted, the slower the ACC responds, and the more likely you are to give into whatever the next temptation is you’re hit with, especially if the temptations come back-to-back. Then you might get no alarm at all, no voice that says, “You really don’t want to do that.”

It’s as if when your willpower gets low, TR falls asleep on watch, and Al has the run of the place. You can also imagine it like those video games where your health meter declines as you get injured—but if you can run around for awhile without being hit again, the health meter starts to climb back up and replenish itself. Crouch behind something and recover and you’re gold, but get hit again before that breather and you’re a dead man.

The Effects and High Cost of Ego Depletion

What happens to you when TR falls asleep and Al takes the wheel? Two things. Both of them bad.

Not Enough Slices of the Pie to Go Around

The biggest effect of ego depletion is what we mentioned in the beginning when we compared willpower to a muscle–when your willpower gets used up on one task, decision, or goal, you have less it for working on other tasks, decisions, and goals. Basically, the more ego depletion you experience, the less willpower you have to control your thoughts, emotions, and actions. There’s only so much willpower pie to go around.

This can be seen in a study that was conducted with two groups of college students. Both groups fasted before being brought into the laboratory. At the lab, the students were taken into a room and sat at a table on top of which two platters of food had been placed—one filled with warm, freshly baked chocolate chip cookies and the other with raw radishes.

One group was told they could eat all the cookies they wanted–the other that they could only nosh on the radishes. The researchers left the students alone in the room, but watched them secretly through a window. The cookie eaters happily enjoyed their repast. The radish-eaters, on the other hand, were seen valiantly trying to resist eating a cookie while glumly biting into the raw roots.

After their snack, both groups were given puzzles to work on that were actually impossible to solve (they were not told this). The students who had eaten the cookies worked on the puzzles for an average of 20 minutes before giving up. But the radish-eaters threw in the towel after an average of only 8 minutes.

Why did the radish-eaters give up so quickly? They had already used up some of their willpower supply on resisting the cookies, and thus had less of it available for working on the puzzles.

Similar studies confirmed this result; once people use up their willpower on one self-control-requiring task, they struggle and do more poorly on the subsequent one.

This phenomenon is something you probably already intuitively understand and have experienced in your own life.

Take your college finals for example. As you focused your willpower energy on studying, you had less of it for other things, and your hygiene and diet went in the crapper. Wearing jeans and eating chicken breasts was replaced by donning pajama pants, scarfing pizza, and guzzling beer (researchers have found that as counterintuitive as it may sound—at least to those who haven’t been in college for awhile—drinking goes up during finals not down, because of ego depletion). You probably chalked those changes up to stress, but ego depletion is also playing a role—you simply don’t have enough willpower to keep all your impulses in check.

Or you may have noticed that on a day you had to make a lot of tough decisions at work, you found yourself short-tempered with your wife and kids when you got home. Because you had used up your willpower earlier in the day, it was harder to control your impulses later on.

In my own life I can track my state of ego depletion on whether or not I respond to negative feedback on the blog. Being a blogger is of course an awesome job, but one of its drawbacks is that you are constantly barraged with baseless criticism, petty complaints, and inane comments from people who miss the point of an article by such a wide margin, it makes you worried about the future of mankind. In the real world, it would be like having a constant stream of people march by your desk saying, “You’re doing that wrong.” “You misspelled that.” “You’re a idiot.” You’ll invariably feel a very strong urge to confront these critics on why they’re wrong or how they really, seriously need to get a life. But I’ve found that responding is a huge waste of time–the naysayer never changes his mind, which only raises your blood pressure further. So I’ve tried to make it a policy to never respond to pointless criticism, and am generally successful…except when I’m suffering ego depletion. A couple of months ago the launch of our new book fell on the same date we were moving into our first house, and since I was putting my willpower towards those and other important things, I found myself lashing out to any unfavorable comment. I just didn’t have enough willpower left to control that angry urge.

This is why you start smoking again when you get stressed. And why they put the candy by the checkout line in grocery stores; after making all those choices on what to buy, your willpower guard is down. This is why it makes sense that ascetic monks stay single and celibate as well; children are specially-patented willpower-sucking machines (“Do not throw crying baby out window, do not throw crying baby out window”) who would consume the willpower needed to wholly focus on one’s spirituality.

This is also one of the elements that makes rising out of poverty so difficult; the downtrodden have a ton of tough decisions to make every day, leaving them more prone to giving into short-term impulses, even if those choices conflict with their long-term goals.

Risk Aversion

In addition to making it more difficult for you to control your emotions, impulses, and behavior, ego depletion also makes you risk-averse in your decision-making. When your willpower starts running dry, you begin to default to the easiest, safest, status quo option, the one that least locks you into a set path, in order to avoid expending any more mental energy. Your brain gets tired and starts to seek the path of least resistance. You become what author John Tierney calls a “cognitive miser” and will focus on just one factor of a decision instead of looking at the whole picture…”Give me whatever one is cheapest.” “Whatever you think is best.” But these “whatever” decisions may not be in your best interest or in line with your long-term goals. It’s like being tired after a day of shopping for a big ticket item, and when the salesman presents you with the store’s suggested package, you sign off on it, even though it’s more expensive and includes features you don’t actually need.


The bottom line is this: Your willpower is a finite resource and when the tank runs dry, you become much more prone to making decisions that distance you from your goals, torpedo your progress as a man, and hurt other people in your life. But as with any force in the world, once you understand how it works, you can become the master of it and learn how to minimize its destructive potential and then strengthen, conserve, and harness the energy for your own purposes. And that is where we will turn next time.

Be sure to listen to our podcast on willpower with Kelly McGonigal:

Willpower Series:
The Force of Greatness
How Your Willpower is Depleted
How to Strengthen Your Willpower and 20 Ways to Conserve It



Willpower: Rediscovering the Greatest Human Strength by Roy F. Baumeister and John Tierney

 Illustrations by Ted Slampyak

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