“Do what thou wilt shall be the whole of the Law” – Aiwass
New developments in biological science suggest your willpower is drawn from a limited supply of chemicals which accumulate in the brain over time.
According to Wired willpower is:
a measurable form of mental energy that runs out as you use it, much like the gas in your car.
Roy Baumeister, a psychologist at Florida State University, calls this “ego depletion,” and he proved its existence by sitting students next to a plate of fresh-baked chocolate-chip cookies. Some were allowed to snack away, others ordered to abstain. Afterward, both groups were asked to complete difficult puzzles. The students who’d been forced to resist the cookies had so depleted their reserves of self-control that when faced with this new task, they quickly threw in the towel. The cookie eaters, on the other hand, had conserved their willpower and worked on the puzzles longer.
Further studies have suggested that willpower is fueled by glucose—which helps explain why our determination crumbles when we try to lose weight. When we don’t eat, our glucose drops, and our willpower along with it. “We call it the dieter’s catch-22: In order to not eat, you need willpower. But in order to have willpower you need to eat,” says John Tierney, coauthor with Baumeister of Willpower: Rediscovering the Greatest Human Strength.
Full story here [my emphasis]
If willpower is thought of as a chemical produced by the brain using specific ingredients (such as glucose) it provides a number of insights into its practical use:
As Tierney explains, “People with the best self-control aren’t the ones who use it all day long. They’re people who structure their lives so they conserve it.” That way, you’ll be able to stockpile vast reserves for when you really need it, like hauling your lazy ass to the gym.
For the moment these findings are probably best used as an insightful metaphor as opposed to concrete reality. Many people believe there is an additional “non-physical” element to consciousness and reject theories of the brain which reduce us to an entirely physiological process. Furthermore the BBC reports criticism of Baumeister’s theory from some quarters:
“It’s almost like there is a self-fulfilling process here,” says Greg Walton, part of a team at Stanford University which has found evidence to debunk Baumeister’s theory.
“The more that people believe that willpower is a limited physiological resource, the easier it is to find ostensible evidence that that is the case.”
[...]
Michael Inzlicht, a psychologist at the University of Toronto argues for a more nuanced understanding of the processes behind self-control.
“It’s clear that consuming glucose can improve self-control,” he says. “But we also know that being in a happy mood improves willpower. Being given a choice improves willpower and paying attention can improve willpower.”
“Glucose does seem to improve things, but this does not mean that glucose is the resource that underlies self-control.”
He believes glucose may have a psychological rather than a physical effect. But he doesn’t entirely disagree with Baumeister’s muscle metaphor.
“I think willpower can be improved and exercising it seems like a promising way to do this,” he says.
Full story here [my emphasis]
The focus upon glucose is in my opinion a red herring. What’s important from my perspective is the practical advice we can glean from these two stories. Firstly it appears willpower is limited depending upon how much of it you have used on any particular day. Secondly your available reserves of it increase the more you use it. Furthermore, when your reserves are low, you can make better use of what you have by, “being in a happy mood [...] being given a choice and paying attention” (see above).
In my personal experience willpower really does develop with exercise much like any other part of your physical body. I suspect this is why it’s widely acknowledged in most self-help/life-improvement circles that changes to your lifestyle are usually managed better if taken one at a time.
Ten years ago I was an overweight smoker. For many years I was locked into the habits of over eating and smoking because I did not understand that tackling both problems at once resulted in a higher chance of failure. I’d usually try to manage both as a New Year’s resolution and then fail around March of the same year. However, when broken into seperate managable chunks, I found that the enormous process of losing weight (77lbs in total) was made easier by my previous success in having stopped smoking. It seemed to me at the time that I had improved my ability to exercise willpower.
The debate is clearly far from over and your thoughts are encouraged in the comments section. I’d be particularly interested to hear from anyone who is on a path where they are deliberately trying to cultivate their willpower. What has hindered you and what helps you?

