Jun 15, 2011
This is a question researchers are addressing at this very moment. We have a few answers right now, and a few more hypotheses we are working on, so there may well be more answers a month or a year from now than we have at this point in time.
Currently, there are a few things that have been shown to improve willpower once it gets depleted. First of all is rest or sleep. Rested, well-slept people have more willpower than tired people. In fact, people’s willpower is often highest in the morning, and lowest late at night. Very few people break their diets first thing in the morning, or go on an impulsive crime spree right after waking up. Instead, these self-control failures are more likely to occur at the end of the day, leading many researchers to conclude that sleep and rest can replenish our willpower. This suggests that if you have to do something that is going to take a lot of willpower, such as working on a difficult project or making yourself exercise when you don’t want to, you may have the most willpower to do so in the morning, when you have recently rested and slept. In addition, it suggests that getting enough sleep each night may improve your willpower during the day. If you are trying to get through each day in a state of sleep deprivation, you may not have enough willpower to resist the daily temptations you are confronted with.
Another mechanism that has been shown to replenish depleted willpower is eating. Exerting willpower takes energy, quite literally, and energy in the form of food that gets converted into blood glucose can improve willpower. Studies have shown that people’s blood glucose levels drop after exerting willpower (such as by resisting some temptation), and raising glucose levels by eating increases willpower. Recent studies have shown that when recovering addicts are hungry, they are more likely to relapse and give into their urges for the addictive substance. Hungry people are more likely to be crabby and impatient rather than using their willpower to resist such urges. When people are already depleted, giving them calories, such as those found in a glass of lemonade, can help them overcome the depletion effects and exert more willpower. Of course, if you are using your willpower to diet, then consuming sugary beverages all day isn’t really the answer to your willpower problems. But it does suggest that fasting might be a counterproductive strategy. Many sensible diet plans require you to eat small, healthy meals frequently so that you never get too hungry, and the willpower research supports this. Hungry people are more likely to give in to their urges of all kinds. Some intriguing studies also suggest that poor nutrition (rather than just being hungry) can lead to self-control problems, and improving nutrition can improve willpower.
Because willpower takes energy, we have recently begun to look at whether caffeine can improve willpower, but the results have been mixed. Caffeine does seem to improve people’s feelings of energy, but that doesn’t always translate into better self-control. Caffeine improves our willpower for some things, such as concentrating on a boring and detailed task, but it has no effect or actually impairs our willpower for other things, such as being polite under trying circumstances.
A good mood is another way to increase willpower after it has been depleted. Positive mood experiences have been shown to overcome the effects of depletion and lead to improved willpower. In several studies, people were put into good moods in a variety of ways, such as watching a humorous video, getting a surprise gift, or interacting with someone they liked. The studies suggested that being in a good mood, for whatever reason, helped improve willpower after people had been depleted.
In addition to trying to get your willpower back once it has been depleted, you can also consider strengthening your willpower in advance. Studies have shown that willpower is like a muscle, and although it can get tired (depleted) with use, it can also get stronger with exercise. Exercising your willpower over the long run seems to give you more willpower to work with, just like exercising your muscles will strengthen them over time. Here’s an example of how to start. Let’s say you usually watch the evening news for half an hour every night. Make a plan to do something that takes a mild amount of willpower during that time, like squeezing a handgrip while you watch the news. After sticking to your plan for several weeks, squeezing the handgrip while you watch the news becomes a (good) habit, and it hardly takes any willpower any more. But your willpower is actually stronger now than it was before you started, so now you can tackle a bigger project that takes more willpower, like giving up cigarettes or making yourself get to bed on time. By exercising your willpower frequently, you can actually end up with more willpower in the long run.
Dianne Tice is a professor of social psychology at The Florida State University.