An even more recent study has failed to replicate the glucose effect entirely, too: Lange, F., & Eggert, F. (2014). Sweet delusion. Glucose drinks fail to counteract ego depletion. Appetite, 75, 54-63 <-- This one also has an interesting survey of the methodological flaws in similar studies.

Also, there's some evidence (still preliminary) that ego depletion effects decline with age: http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0026351 <-- free access paper if anyone wants to read it. It basically looks at a meta-analysis by Hagger done about 2010? I think, and shows a significantly higher effect for younger people (which, being psyc and reliant on college students most of the time, is most of them) - then conducted their own study and found the same (using groups of <25 vs. 40-65). Since 25 is approximately when the pre-frontal cortex is fully finished maturing, maybe the effect has something to do with that.

Also, in terms of the 'out of willpower' and giving up thing... several studies have shown that with sufficient incentive (money, being told the research will help develop Alzheimer's therapies) the ego depletion effect goes away (but then comes back triple-fold on a third non-motivated task). Also, people tend to conserve willpower when they expect to need it later. So you don't have to give up, it might just be a bit harder - but if a few dollars (literally what it was) can motivate someone out of it then you can probably motivate yourself out of it for anything important. This is where the muscle analogy comes into play, like an athlete resting for a big match then pushing through discomfort during it.

^Ref for the last paragraph: Muraven, M., Slessareva, E. (2003). Mechanisms of Self-Control Failure: Motivation and Limited Resources. Personality and Social Psychology Bulletin, 29(7), 894-906

All in all, I'm not convinced one of those things is going on, because there's no explanation there as to why they would happen more for a task that requires self-control than one that doesn't. Most ego-depletion studies match up tasks to make them the same domain, often the same length and tediousness. Why would a task requiring more self-control give you more physical discomfort, hunger, thirst or indignation? The anxiety about willpower depletion I can get behind, but that's only for people who know what they're being tested on.

I once asked a room full of about 100 neuroscientists whether willpower depletion was a thing, and there was widespread disagreement with the idea.

In which year did you do the asking?

Related earlier posts: Kurzban et al. on opportunity cost models of mental fatigue and resource-based models of willpower, Deregulating Distraction, Moving Towards the Goal, and Level Hopping , Why Self-Control Seems (but may not be) Limited, also this comment.

From the paper discussed in the first one:

Take, for example, the reaction to our claim that the glucose version of the resource argument is false (Kurzban 2010a ). Inzlicht & Schmeichel, scholars who have published widely in the willpower-as-resource literature, more or less casually bury the model with the remark in their commentary that the “mounting evidence points to the conclusion that blood glucose is not the proximate mechanism of depletion.” ( Malecek & Poldrack express a similar view.) Not a single voice has been raised to defend the glucose model, and, given the evidence that we advanced to support our view that this model is unlikely to be correct, we hope that researchers will take the fact that none of the impressive array of scholars submitting comments defended the view to be a good indication that perhaps the model is, in fact, indefensible. Even if the opportunity cost account of effort turns out not to be correct, we are pleased that the evidence from the commentaries – or the absence of evidence – will stand as an indication to audiences that it might be time to move to more profitable explanations of subjective effort.

While the silence on the glucose model is perhaps most obvious, we are similarly surprised by the remarkably light defense of the resource view more generally. As Kool & Botvinick put it, quite correctly in our perception: “Research on the dynamics of cognitive effort have been dominated, over recent decades, by accounts centering on the notion of a limited and depletable ‘resource’” (italics ours). It would seem to be quite surprising, then, that in the context of our critique of the dominant view, arguably the strongest pertinent remarks come from Carter & McCullough, who imply that the strength of the key phenomenon that underlies the resource model – two-task “ego-depletion” studies – might be considerably less than previously thought or perhaps even nonexistent. Despite the confidence voiced by Inzlicht & Schmeichel about the two-task findings, the strongest voices surrounding the model, then, are raised against it, rather than for it. (See also Monterosso & Luo , who are similarly skeptical of the resource account.)

Indeed, what defenses there are of the resource account are not nearly as adamant as we had expected. Hagger wonders if there is “still room for a ‘resource’ account,” given the evidence that cuts against it, conceding that “[t]he ego-depletion literature is problematic.” Further, he relies largely on the argument that the opportunity cost model we offer might be incomplete, thus “leaving room” for other ideas.

Indeed, willpower and working memory are both strongly mediated by the dorsolateral prefontal cortex, so “distraction” could just be the two functions funging against one another.

If true, this is the most important thing I have read in several months. Thank you.

This article has materially helped me over the past couple of weeks. Before, I believed that ego depletion occurred from physical, mental, or emotional effort, and I viewed it as a depletable resource. This gave me a massive excuse to slag off after I finished a task.

But the idea that willpower gets a boost as soon as the brain perceives a reward gave me a different way to look at it. Now, I focus on the reward/'hit' I get from achieving small goals. As long as I celebrate each finished task, I win, and my willpower should increase rather than decrease!

This makes me feel like a badass. If I can keep the big picture in mind, and see how each small goal advances me toward my ultimate goal, and only get more revved up everytime I finish a task, then I'm a freaking Punisher.

So thanks.

Thanks for writing a post about this!

A thought on akrasia:

I wonder how much "going meta" is a serious hindrance. Attentional and decision resources are then spent at the meta level instead of the base level. Too much in the moment confusion, optimization and consideration of process, and not enough doing.

A new study by Sripada, Kessler, and Jonides (2014) found that Ritalin blocked the willpower depletion effect, and included some evidence that the amount of mindwandering might mediate the effect. I haven't taken a close look at the paper, but here's the abstract:

A recent wave of studies—more than 100 conducted over the last decade—has shown that exerting effort at controlling impulses or behavioral tendencies leaves a person depleted and less able to engage in subsequent rounds of regulation. Regulatory depletion is thought to play an important role in everyday problems (e.g., excessive spending, overeating) as well as psychiatric conditions, but its neurophysiological basis is poorly understood. Using a placebo-controlled, double-blind design, we demonstrated that the psychostimulant methylphenidate (commonly known as Ritalin), a catecholamine reuptake blocker that increases dopamine and norepinephrine at the synaptic cleft, fully blocks effort-induced depletion of regulatory control. Spectral analysis of trial-by-trial reaction times revealed specificity of methylphenidate effects on regulatory depletion in the slow-4 frequency band. This band is associated with the operation of resting-state brain networks that produce mind wandering, which raises potential connections between our results and recent brain-network-based models of control over attention.

willpower depletion" might be nothing more than mental distraction by one of these processes

I view it as competion by different processes for a shared resource.

A robust system would have built in mechanisms for time sharing, so that one want doesn't always override the others. Different wants get allocated only so much, and then has to compete again, but at a handicap; some handicap associated with the want, some handicap associated with the justification/payoff for the want.

I'd guess that cycling different stimuli would be more effective than using the same one again and again, and that timing the reinforcement well prior to a "give up" might be effective as well. Keep "topping up" the motivation, instead of letting it run down entirely.

I suspect boredom to be another thing that can result in willpower depletion: it's hard to stay engaged in something when it's boring. It may be possible on less difficult tasks to keep going longer, but it eventually begins to drain on you (although maybe this is covered by wanting to do some other specific thing, but I suspect it was distinct in that you can be bored without having something you would rather be doing).

Maybe try having a sip of water or a bit of food if your diet permits it.

Why not have enough water so that you aren't thirsty?

I have a relevant blog post on models of willpower.

To add an update from 2016.

Apparently some recent attempts to replicate, making sure to avoid the file drawer effect have not been able to replicate many of the older results.

http://www.slate.com/articles/health_and_science/cover_story/2016/03/ego_depletion_an_influential_theory_in_psychology_may_have_just_been_debunked.single.html

https://osf.io/92dhr/wiki/home/

"The replication team ran that same experiment at 24 different labs, including ones that translated the letter e task into Dutch, German, French, and Indonesian. Just two of the research groups produced a significant, positive effect, says study co-author Michael Inzlicht of the University of Toronto. (One appeared to find a negative effect, a reverse-depletion.) Taken all together, the experiments showed no signs whatsoever of Baumeister and Tice’s original effect."

.

“Meta-analyses are fucked,” Inzlicht warned me. If you analyze 200 lousy studies, you’ll get a lousy answer in the end. It’s garbage in, garbage out.

This is very interesting. When I was dieting I noticed that a taste of food (but not diet coke which I drink tons of) was often enough to give me more physical and mental energy, but that it also made me feel more hungry, possibly because it set off the stomach acids ready for digestion. I wondered at the time if it could be explained by glycogen. Glycogen as I understand it is how the body stores readily available sugars that are not in the blood but where they're a lot more easily broken down than in fat. (It's also heavier than fat per calorie so it explains a lot of high early weight loss effects). I thought that maybe tasting food prompted the body to release some glycogen into blood sugar so it had the energy for digestion.

Of course this doesn't mean that distractibility isn't a Thing too. Will power is almost certainly one of those things that's 'a bit more complicated than that'...

I thought it was called 'ego' depletion because getting the ego out of the way is most of the problem. I.e. the ego is wasting too much time on the 'story of self' narrative.

While these are all interesting empirical findings, there’s a very similar phenomenon that’s much less debated and which could explain many of these observations, but I think gets too little popular attention in these discussions.

But you don't explain the findings!

I once asked a room full of about 100 neuroscientists whether willpower depletion was a thing,

I don't even know what that question is supposed to mean.

You link ego depletion (willpower depletion and decision fatigue alternative terms) to working memory, based on neuroscientists refusal to reify the former. But you neglect that, neuroscientists would deny that working memory is "a thing."

The psychological findings are robust. That the first-proposed physiological explanation is dubious doesn't disqualify the phenomena.

The opponent process theory in mentioned in the wikipedia article is promising.

Who says willpower limitations are a function of limited capacity? This is something of an engineer's favored explanation. A better explanation is probably rooted in evolutionary psychology rather than inherent capacity limitations. We evolved with opponent processes governing control and gratification.

Attributing willpower depletion to "distraction" isn't an explanation. Distraction probably has causal relevance, but it isn't a magic wand to wave away psychological findings.

The OP is amateurish.