Self-regulation Failure (Part 2): Willpower is Like a Muscle
Procrastination: Why willpower fails us.
Posted Feb 23, 2009
Roy Baumeister, his colleagues (e.g., Matthew Gailliot, Todd Heatherton, Mark Muraven, Kathleen Vohs) and his students have been focused on the investigation of self-regulation strength for the past 10 years, and their research has spawned related projects such as the one conducted by my colleague Dr. Joseph Ferrari (DePaul University). Although there have been many studies done, they share a common design.
In the typical experiment, research participants are randomly assigned to two groups. Both groups expect that they will participate in two tasks, but there is an important difference between the groups in terms of the self-regulation demanded of them.
The experimental group is required to exercise a great deal of self-control in the first task, whereas the control group is simply asked to do the task. For example, both groups may be asked to watch a funny film, but the experimental group is required to suppress their emotional expression while the control group is given no specific instructions about how to react. In another case, the experimental group may be required to persist at a very boring task (e.g., doing a very long sequence of simple arithmetic problems), whereas the control group does a task of equal length but does not require self-regulation to overcome boredom. A final example of this design is one where both groups arrive hungry, but the experimental group is instructed to eat radishes while resisting a tempting plate of cookies, whereas the control group is allowed to eat the cookies or the radishes (you guess which is more popular). In each of these experiments, the experimental group exercises self-regulation, while the control group does not.
Once this first task is completed, both groups are then asked to complete a second task that involves self-regulation. Both groups need to self-regulate their behavior to achieve success, and the key outcome measure is how persistent each group is. For example, typical second tasks include things like: complex figure tracing, solving complex anagrams, drinking an unpleasant (but not harmful) "sports drink," and, my favorite, resisting drinking free beer (even though a driving test is expected to follow). The main idea is that this second task requires self-regulation, and the hypothesis is that the experimental group will perform more poorly (not persist as long) because they have already exhausted their ability to self-regulate.
The findings of these studies consistently demonstrate that the experimental group performs at a lower level than the control group. Given the difference in the self-regulatory demands on Task 1, the researchers conclude that the experimental group has exhausted self-regulatory strength, at least temporarily, and therefore are unable to muster the self-regulation required for the second task. In one practical example of this, one study showed that after coping with a stressful day at work, people were less likely to exercise and more likely to do something more passive like watching television.
Willpower is like a muscle
Based on these studies, Baumeister and colleagues have concluded that willpower is like a muscle. It can be fatigued with use, so that it can not perform indefinitely.
Actual physical depletion
Some very recent research has indicated that one of the physical correlates of this self-regulatory depletion is the depletion of blood glucose, and a drink of juice replenishes both the glucose levels and the ability to self-regulate. These are interesting findings that have clear implications for our self-regulatory goals.
Self-regulation comes with a cost, and we can only self-regulate so much at any one time. Although willpower is one of those "invisible" sorts of concepts (unlike muscles which seem to reveal strength more visibly by size), it still has limits.
Of course, drawing on this metaphor that willpower is like a muscle, it would make sense that we should be able to develop this muscle's strength. There are a number of studies that indicate just that. For example, as Matthew Gailloit has summarized (see reference below), there is evidence that even 2-weeks of self-regulation through continuously maintaining good posture improved performance in the kind of experiments discussed above. This little bit of self-regulatory exercise seems to strengthen the willpower muscle.
In fact, other studies provided evidence that physical exercise programs led to decreased smoking, alcohol, caffeine and junk food consumption, and even reduced impulsive spending, watching television and the tendency to leave dishes dirty in the sink! You can learn more about strengthening willpower by listening to this archived NPR broadcast (and if you look at the bottom of the list you'll find an older interview with me about procrastination as well).
What interests me most are the studies that show how simple things like getting better sleep or boosting positive emotions reduced the effects of self-regulation depletion. In addition, heightening motivation to self-regulate has also been shown to be effective.
Next time, I'll reflect a little more about what this motivation issue might mean.
Ferrari, J. R., & Pychyl, T. A. (2007). Regulating speed, accuracy and judgments by Indecisives: Effects of frequent choices on self-regulation depletion. Personality and Individual Differences, 42, 777-787.
A recent summary of self-regulation from a personality perspective and covers all of the topics discussed above is provided in:
Gailliot, M.T., Mead, N.L., & Baumeister, R.F. (2008). Self-Regulation, In O.P. John, R.W. Robbins & L.A. Pervin (Eds.), Handbook of Personality: Theory and Research (pp. 472-491). New York: The Guilford Press.
Something available at the click of your mouse is:
Baumeister, R.F., & Vohs, K.D. Willpower, choice and self control. In George Loewenstein, Daniel Read, Roy F. Baumeister (Eds.) Time and Decision.