I recently read this book. I've tried to summarize the main points below -- you can read my notes here (MSWord doc). You might also find Derek Sivers' notes useful, which can be found here.

NOTE: The general model of willpower (as a finite resource consumed with use) used in this book does not seem to represent a scientific consensus -- see the comments for more detail.

General Claims

  • Glucose acts as willpower fuel. As willpower levels drop, so do glucose levels. Willpower can be restored by raising your blood sugar. (pp. 44-48)
  • You have a finite amount of willpower that becomes depleted as you use it, and you use the same stock of willpower for all manner of tasks. (p. 35)
  • Willpower depletion amplifies emotions, desires, and cravings[i]. (pp. 30-31)

Willpower Depletion

  • Controlling emotional reactions depletes willpower. (p. 25)
  • Attempting to control thoughts (say, trying not to think of a white bear) depletes willpower. (pp. 26-27)
  • Chronic pain causes ongoing willpower depletion. (p. 36)
  • Being sick depletes glucose, which negatively affects willpower. Related note: Driving a car with a bad cold has been found to be even more dangerous than driving when mildly intoxicated. (pp. 59-60)
  • Making decisions (even trivial ones) costs willpower, and making decisions for other people costs less than making them for yourself. Making decisions that you enjoy costs less willpower than those which you do not. (pp. 94-95)
  • Uncompleted tasks and unmet goals tend to pop into one’s mind – this is called the Zeigarnik effect. Completing the task (or making a plan to do so, the more specific the better) will cause your unconscious to stop nagging you with reminders.[ii] (p. 81)

Restoring Willpower

  • Eating foods like white bread, potatoes, white rice, and sugary snacks produce boom-and-bust cycles because they are converted into glucose so quickly. Foods which are converted more slowly (providing fuel more steadily) include most veggies, nuts (like peanuts and cashews), many raw fruits (like apples, blueberries, and pears), cheese, fish, meat, and olive oil. (These foods are said to have a low glycemic index.) (pp. 59-60)
  • Sleep helps to restore willpower – in particular, sleep deprivation causes impaired processing of glucose (and, over time, a higher risk of diabetes). (pp. 59-60)
  • Being in a clean room appears to increase self-control, and being in a messy room appears to reduce self-control.[iii] (p. 156)


  • Focusing on a single self-improvement goal increases your chances of success, as each simultaneous goal increases the demands on your willpower. (pp. 37-38)
  • Conflicting goals cause increased worrying/rumination, decreased motivation, greater amount of physical sickness, and more depression and anxiety. (p. 67)
  • Reluctance to give up options increases when willpower is low.[iv](p. 99)
  • Focusing on past achievements seems to increase contentment with one’s current situation, while focusing on the road ahead increases motivation and ambition. (p. 120)
  • People are often not very good at predicting how they will behave in an excited emotional state while in an unexcited state – this is often referred to as the hot-cold empathy gap. (p. 148)
  • Precommitment can make it more likely that you will not succumb to temptation during times of low willpower.[v] (pp. 151-153)

I declare Crocker's Rules.

[i] I didn’t see enough evidence to conclude whether the cravings are actually stronger, or people are simply less able to resist them, or both. The book claims that both are true.

[ii] The book seems to imply this mental nagging costs willpower, but I don’t recall it being explicitly stated. GTD is also mentioned, and the lack of Next Actions which one has the materials to execute being included in plans causing people to procrastinate. (p. 79)

[iii] The relevant experiment was conducted in a laboratory, so there is no possibility of the experimental results being affected by the fact that people with more self-control may keep their house cleaner. Self-control was measured in ways like being willing/unwilling to week for a larger sum of money instead of receiving a smaller sum immediately, and choosing healthier foods over sugary snacks.

[iv] I wonder if this means that people are more likely to ignore opportunity costs.

[v] ‘Conserving willpower’ is also mentioned around here, which seemed to imply that effective precommitment helped reduce the willpower costs of overcoming constant temptation by making the decision easier.


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Here is a skeptical reply to Baumeister on willpower:

This idea has a visceral, compelling feel to it - it does feel like I'm tired and drained after making decisions - and the idea has received a tremendous amount of attention from scientific and lay communities alike, perhaps partially explaining the duo of scientist/journalist on the dust jacket.

There are a number of problems with the model, and in this post, I'll talk about one of them: the model has been falsified a number of times, including by research performed in the lab of the proponents of the model.

Note that one's perception of cognitive resource depletion matters.

It seems to me that the way a task is framed greatly affects how much willpower it requires. If you give a college student tasks of equal cognitive difficulty, one of which is part of the computer game and one of which is a homework assignment, they typically require much more willpower to complete the one that's a homework assignment.

So I don't see how the fact that telling people they have unlimited willpower works falsifies the model. It could just reframe tasks so they require less willpower.

If willpower is the ability to sustain activity in the absence of reinforcers, maybe telling people they have unlimited willpower causes them to see their willpower flagging as a reinforcer ("my willpower's flagging, but I'm so mighty that it will never run out! Heck yes!")

Which is a very nifty scheme if you could make it work: whenever you have been going without a reinforcer for a while, just give yourself a pat on the back for being so awesome and that's your reinforcer, allowing you to go on forever.

This reinforcer bit nicely explains the surprise gift finding mentioned. Maybe willpower depletion rate is proportional to length of time you have been exerting effort without a reinforcer, or something like that.

By the way, this perception of willpower depletion strategy could make a good situation/response spaced repetition card:

Front: You notice you are pushing yourself.

Back: "Bring it on, I could do this all day."

It seems to me that the way a task is framed greatly affects how much willpower it requires.

Yes; I can't remember which overcomingbias posts it was in, but Robin Hanson has floated a theory that willpower is a hack whereby, for social reasons, we override our natural and correct (in the EEA) instinct. Obviously, it doesn't pay to make such an ability infinitely strong; people who go on hunger strikes to make a point have few offspring. So, a task framed as something useful in the EEA would require much less willpower than something framed as socially praiseworthy, but otherwise harmful.

For those interested, that blog post has two follow-up posts which criticize the part of the theory claiming that the resource depleted during ego-depletion is glucose: Glucose Is Not Willpower Fuel and Should You Consume Sugar to Improve Your Self-Control?.

With all that, ego-depletion theory really looks well beyond shaky. The author of these posts also claims we still have no actual working theory of fatigue.

Uncompleted tasks and unmet goals tend to pop into one’s mind – this is called the Zeigarnik effect. Completing the task (or making a plan to do so, the more specific the better) will cause your unconscious to stop nagging you with reminders.

That's the basis of the book Getting Things Done. He recommends doing all things that take two minutes immediately, but otherwise having an organized method off dealing with all issues, where it's all written down and planned, so no nagging is required. Everything is handled, and you know it is handled, so your brain doesn't have to nag you about it.

For me, this was actually the single most striking chapter of the book (as anyone in #lesswrong learned while I was reading it...) The Zeigarnik effect is one of the main reasons I ever meditate - to let the little damn thoughts pop while I'm not doing anything so I can write them down on an index card and deal with them later. That alone makes the first 5-10 minutes of meditation worthwhile.

The information that willpower is a limited resource which must be managed carefully is very useful, and I think it would change how many people make decisions.

It also has the potential to challenge the popular concept of laziness- if willpower isn't an infinite resource that comes out of thin air than it's not morally wrong to refuse to waste it on something, when you have a more important goal to direct it towards.

However, I think the medical information on blood glucose here is wrong. Metabolically healthy people can eat a reasonable quantity of high glycemic index/load foods, and never experience a low enough glucose crash to inhibit willpower later on even if they decide to transition all the way into a long term fast afterwards. Sure, abnormally low blood glucose inhibits willpower but not within the range of normal healthy glucose fluctuations but only in a person with mild reactive hypoglycemia- usually related to mild insulin resistance.

While a pathological condition, insulin resistance has become almost ubiquitous in the United States in the past few decades (the metabolic syndrome epidemic). Metabolic syndrome/insulin resistance is not actually caused by high glycemic index foods, it's symptoms are simply exasperated by them in the short term. Also, glycemic index of isolated foods is somewhat irrelevant because food combinations have very different combined properties. For example, a baked potato with butter causes glucose levels to rise much slower than a plain baked potato.

I would need to give a lot more information here to fully clarify the evidence behind this position, however it's somewhat tangential to this thread.

I don't think anyone would object if you gave us links and studies to follow up on...

Excellent summary! I wish all link posters were as thorough.

A couple typos:

Eating foods like white bread, potatoes, white rise

=> "rice"

Conflicting goals cause increased worrying/rumination, decreased rumination

=> probably "motivation"

Fixed, thanks.

What are Glucose levels like in someone either a) fasting or b) in a state of Ketosis? I imagine, but haven't seen any data, that they are more stable since you are relying on internal stores which can be converted at a steady rate vs. variable timing of intake and quality of food sources.

I'm also curious if there is more detail that could be shared about attempting to control thoughts depleting willpower. For example, a strategy I have adopted for Meditation is to relax thoughts rather than attempting to use "force" to control them. I imagine the question is too specific, but aside from the one example (trying not to think of a white bear) do they offer any other examples of what is considered attempting to control your thoughts?

I was actually looking for an errata page for the minor mistake on page 119, where it says "three billion" for "three million". The notes are clear, but it still stuck a thumb in my eye.

For what it's worth, I rate the book as good, though a bit drier than The Willpower Instinct. Also, this book seemed less focused on specific things to do.

I've read this book in the past and am looking at "The Willpower Instinct" right now. Since you seem to have read both, I'd love to hear any other thoughts you might have on the comparative pros/cons of each of them.

Not even sure this comment is directed at me, but quite sure my reply is quite late. (In terms of deciding to reply, it would be helpful if LW revealed something about your recent activity in the flyover.)

At this point I don't recall the books in sufficient detail to address your question properly. I do fit them into the general scheme of compulsive behavior. My general take on habitual behaviors (including compulsions) is that certain parts of the lower brain are the mechanical keys to the compulsions, but there's a scale before things get into extremes like OCD. The complicated part is that there are many paths into the lower brain. On that foundation, my basic theory is that some people are more subject to compulsive behaviors (which can be roughly mapped to having less willpower), but the trigger for a compulsive behavior is a point of attack to change that behavior. Some triggers are definitely worse than others, so switching to a less troublesome trigger is an improvement.

Supplemental reading? I am a Strange Loop by Hofstadter is relevant, though my interpretation is different from his. I think all of us run various mental programs, and his recursive loops are only a relatively minor subset. (But I think his Godel, Escher, Bach is still a must read, especially the chapter on translation.) Quite recently I read Descartes' Error by Damasio, which is relevant. He's approaching these problems from a more mechanical level, but with heavy consideration of how emotions are involved in decision making. Also the books from Malcolm Gladwell and Dan Ariely are excellent.

So after I read Baumeister & Tierney's book, I began wondering whether one could run a little self-experiment to test it. The obvious approach: randomize consumption of some peanut butter crackers (low glycemic index). But then I saw the criticisms of it and failed replications, and I became less enthusiastic: I'm already primed for depletability, so non-blind consumption is predicted by the skeptics to show an effect. So blinding seems necessary.

How do I blind it? I have a few hundred 00 capsules left, but I would blow through them fast filling them up with peanut butter.

The study I heard about in another pop-sci book mentioned subjects drinking lemonade which either had added glucose or splenda. Fill two glasses, then shuffle them around and grab one blindly in the dark?

Baumeister & Tierney do discuss how to use the sugar theory practically, and they discourage people from swilling sugar rather than snacking on healthier low-glycemic index stuff (such as nuts). On the other hand, now that I think about it, they weren't talking about self-experimentation so much as long-term habits, so maybe that's not a bad suggestion after all...

Willpower depletion seems to depend (at least to some extent) on whether you believe willpower is a finite resource or not. What that means for people who are aware of that fact, I haven't the slightest idea, but it's probably like what happens to people who have a thorough understanding of the placebo effect and are aware they may be experiencing it.

Your willpower gets depleted only if you think it does? So...why do that then?

If you read in a reputable-looking book that your willpower is depletable, and you hadn't heard any good evidence to the contrary before, you might end up believing that. That's what happened to me for the span of a couple of years, in fact.

Ah, well, on general grounds I have a rather low expectation of all work on experimental psychology.

FWIW, though, one of the findings of the biases literature is priming. If one takes that one seriously, it should lead one to take less personally seriously any of the rest.

Good food for thought. I'd like to hypothesize that willpower is not limited in a fixed sense, but also not unlimited. (This might be obvious, but worth thinking through.)

Willpower seems to be increased by practice. People who are disciplined seem to have more willpower to apply to a given problem.

Hmm... alternative hypothesis: is it that they have more willpower, or does their discipline - their daily habits of work and self-improvement - mean that they're wasting much less energy on deciding whether to do something, many times each day? It's probably much more energy-efficient to just do something than to keep procrastinating - i.e. to decide to put it off another 5 min, hour or day, again and again.

[I just noticed I'm conflating energy and willpower... and that I don't have a clear definition of willpower.]

Re John Maxwell IV's point, earlier in this discussion, that willpower being seen unlimited could be a useful reinforcer - I can see that it would be a useful thought to psyche myself up, but I'd bet that it's a false belief. An optimally useful belief might be to have an accurate estimate of my own willpower, and to work on the basis that it might be at the high end of the estimated range - so I push myself, but also recognize my need for recovery, and don't exhaust myself.

Why don't I think willpower is unlimited? I heard of a study* where people who have have been making decisions are less able to resist unhealthy snacks. This fits with my experience and that of others I've talked with. (To try and be thorough, an alternative hypothesis of the study could be that making decisions increases the body's desire or need for glucose - a related but not identical claim. I know which hypothesis makes more sense in my own experience, but I'd like to know if there's more solid evidence.)

Please point out errors & help reduce the fuzziness of this argument.

  • "I heard of a study" should trigger your weasel words detector. Take this claim with a grain of salt since I'm being too lazy and/or time-efficient to go and find information about the study or studies.

** I just noticed the formatting here - writing John Maxwell IV with the underscores instead of spaces turns out as John_Maxwell_IV

I think this whole reasoning about willpower as a energy (whether renewable or not) is horribly confused. It is just a surface analogy taken too far. For physical work we have muscles that burn calories -- that is a scientific fact. Mental work can also make us kind of "tired", but that is not enough to conclude that we have some analogical mental muscles that burn mana points or whatever.

A big difference is that unlike physical work, mental work does not make us literally tired, but more like frustrated. One can think about pleasant things all day long, one can do their hobby, even when it is difficult, all day long, without getting tired. But a work that does not make sense, makes one burn out quickly. When one solves a problem, the mere information that the problem is easy to solve, gives one a lot of "energy"; on the other hand, a suspicion that there is a mistake in a problem which makes it unsolvable, takes the "energy" away. I guess in a similar way, belief in one's "unlimited willpower" makes the task easier, while belief in a "limited willpower, already largely spent" makes the task more difficult.

I propose a completely different point of view that includes what happens inside the human mind. Human brain is basicly a problem-solving machine, by nature focused on problems of survival and reproduction, and all related stuff (like status, human relations, etc.). All other goals must be somehow connected to this basic goals, even if the connection is only imaginary. This is what the word motivation means: you connect solving of problem X with something that given person already cares about; for example you say "solving problem X will make you rich" or "solving problem X will make people like / admire you". Thus the brain includes solving problem X in its collection of problems worth solving, and that makes a human willing to do it.

The opposite of this process should be called demotivation; it is usually not done explicitly, but it just happens under some circumstances. If motivation is seeing a link between X and one's natural goals, demotivation is weakening of this link; a person becoming suspicious that maybe X does not really contribute to one's goals, or at least that X is so difficult that a completely different way to achieve one's goals would be more efficient. Simply said, my model is something like "the brain chooses a rational solution, but it may have completely wrong data on its inputs". For example a little problem on the way towards X may create an exaggerated thought "X is impossible", which is followed by a rational conclusion "I don't want to do X anymore" -- and the person reports being too tired to do X. Next day the little problem is forgotten or put in a correct perspective, and the person is ready to work on X again.

If this model is good, the the "unlimited willpower" is simply a strong conviction that X is possible and efficient to achieve one's goals; a convinction so strong that it can't be even temporarily unbalanced by little problems.

Where exactly is the glucose in this picture? Perhaps consuming glucose is a chemical reinforcement which gives the organism a signal "whatever you were doing, it is good for your survival". Simply said, you are doing X because you believe "doing X is good for me". Then you have some problems and switch to "doing X does not work". Then you eat glucose and your body says "you are on the right path". And in some situations the brain interprets it that perhaps X is actually good (as if X somehow made you eat the glucose), so it is worth doing X again.

I agree with you for some of your opinions here. The fact of humans having limited willpower rather confusing. It provide one with no option instead settle down believing so. This is where the claim relevant for point of:

1) Uncomplete task will pop up in one's mind rather often then not when the task is completed. The author imply sometimes we have to settle down something with less than perfect eg: the one mention in the book about finding perfect mate. So here maybe the author purposely or not-of course out of my reach to know author's state of mind- want us to settle down with less than perfect fact that willpower indeed finite.

Here, I am not sure I follow your reasoning on glucose on willpower. This is just of my opinion, so please correct me if anything wrong with that. For long, medical community has accepeted the fact that glucose indeed a fuel for your brain. Deprive of glucose will not only distorted your perception, concious but can cause death indeed.

Thus, author simply want us to know that unhealthy diet and eating habit indeed do more harm on your precious brain. For most century, humans are believing with those three great Greek-think-tanker of Socrates, Plato and Aristotle that our centre of thinking and feeling is at the heart! That's why for most of them discipline and willpower is indefenite, simply be because they dont even know there is brain, let alone glucose.

Nowadays, scientific and meta analysis research has proven glucose is the only fuel for our brain. The fact that glucose is so important that when our body deprive of it, our muscle and fat will be mobilized and catabolized becoming glucose! Without glucose, your brain will be chaotic and function improperly. This is where all your willpower, cognitive, judgement and concious perish!

Nonetheless, this book is very an eye-opening in the sense it give an insight and possible new dimension of looking for willpower. For some, willpower is indefinite, the rest will commit to agree that it is finite. Feel free to do so and say it loud because both are not wrong. Between those two, it is only a very fine and thin line dividing them. You will definitely loss your soul and life, let alone willpower if you are not eating well.

Anyway, thank you for the summary here. I enjoy reading it and it serve me well to understand what this book all about. I agree for most of the proposition put forward in this book, the rest maybe worth to be considered for future improvement. Thank you.

Certainly, energy in some form (glucose) is necessary for brain to work. This part is obvious. The question is, how much energy do different brain tasks require. By the way, the brain is doing some work even when I am not thinking, even when I am not using willpower. So the question is, does the brain need more glucose for tasks that require willpower, as opposed to tasks that do not require willpower?

Only if the willpower-related brain tasks need more glucose than willpower-unrelated tasks, only then we can treat the willpower as a limited resource. But if it would happen to be the opposite, if willpower-related and willpower-unrelated tasks need the same energy, then we could take the willpower as unlimited resource (and the glucose as simply the fixed cost of living).

Glucose acts as willpower fuel. As willpower levels drop, so do glucose levels. Willpower can be restored by raising your blood sugar.

How strong do they claim this effect is? Does it work for higher-than-normal BG (to raise willpower) or only lower-than-normal (to lower it)?

I'm a type-1 diabetic and have been in both situations a lot. More generally, type 2 diabetes is so widespread today that there's a huge amount of (unreliable) data about diabetics. If this claim is true, I'd expect it to show up in metabolism research.