Theory about willpower and self-control has changed


Sarah Berry (Stuff) calls it self-control. New Scientist calls it willpower. Whatever you name the drive to carry on ignoring distractions, we see in both articles a recent change in how we regard self-control/will-power.

An older theory held that you “charge up” – say with glucose – ?and then run this down as the day goes by.

According to the idea that willpower is limited ? known as ego-depletion theory ? the difference in people?s ability to stay strong in the face of temptation can be explained by the amount of fuel in our mental reserves. Social psychologist Roy Baumeister, then at Case Western Reserve University in Cleveland, Ohio, came up with the idea in 1998 after a series of experiments. When people were asked to concentrate on solving a difficult maze, say, or a series of anagrams, their performance on a second mentally taxing task dropped compared with control volunteers whose initial task was easy. He concluded that willpower is like a muscle that gets fatigued with overuse.


Sarah’s take is:

The stereotype is that we suddenly capitulate to our chocolate craving once 3pm hits, struggle to work well in the afternoon or evening, and smash the chardies after work because our will has been weakened from exercising self-control all day.

(Love that “smash the chardies”). Sarah goes on to report:

The researchers tracked what times the students (Uni of Toronto) logged into the program, how long they spent in the program and how they performed on memory tests.[…]

“Users’ login patterns were steady throughout the day and increased substantially towards the evening, while their session lengths were longest later in the day relative to earlier,” they wrote. “This is the exact opposite of what we would have expected from our predictions derived from the resource model of self-control, where a mentally effortful task should be unappealing later in the day.”


Back to the New Scientist article where it says that the ego-depletion model came under attack as other labs found almost no evidence for this effect.

Seeing willpower and motivation as being more about mindset than blood sugar level might help clear the confusion. In 2010, Dweck and her colleagues Veronika Job at the University of Zurich and Gregory Walton, also at Stanford, repeated Baumeister?s experiments, but this time asked volunteers beforehand whether they considered willpower to be a limited resource depleted by effort. They found that those who believed that willpower is finite showed the usual ego-depletion effect, whereas those who believed that willpower is potentially unlimited showed no signs of running out of steam in the second task.

Further studies have discovered that you can improve willpower just by telling people that such a thing is possible. When people were shown statements such as ?it is energising to be fully absorbed with a demanding mental task?, they continued to improve through a tough 20-minute memory challenge. Another group that was told willpower is limited stopped improving about halfway through the task.

This has been convincing enough for a change of theory.

Baumeister recently revised his theory to take this into account. In a book chapter published last year with his colleague Kathleen Vohs at the University of Minnesota, he argues that while there is a limited resource behind self-control, it rarely, if ever, runs dry. According to the revised theory, whether we are able to maintain self-control comes down to our judgement about how much willpower juice we have left and how we choose to allocate these reserves. As with physical effort, in which our muscles feel tired long before they are close to collapse, how long we can keep going is all about how much energy we think is left.


It is really nice to know that, providing we are feeding ourselves well enough, we probably have more willpower reserves than we think. Simply by “motoring along” our “batteries” will maintain their charge ready to be called on to get that mental job done as long as the motor keeps running.

Of course, top athletes have known this all along…

This post was written by Intern Staff