Willpower sounds cryptic. We’re either disciplined or we’re not. Some people seem to ‘just have it’ while others don’t. Yet, modern science has dissected the phenomenon of willpower carefully. In essence, willpower functions like a muscle and can be both trained and depleted. There are certain factors that determine how much willpower you have, factors which you can understand and leverage.

The importance of willpower is often highlighted by the Stanford Marshmallow Experiment, which I highly recommend you watch before continuing reading this article. In the video, little children are confronted with a choice: They either get one marshmallow now, or two marshmallows later. Yet, the task comes with a difficulty: The children had the marshmallow placed on a plate in front of them during the entire waiting time. Only if they did not eat that marshmallow within the first ten minutes did they get the second one. You can find the paper here.

Most interestingly though, this experiment was part of a long-term study. The kids that made the entire 10 minutes were not only adorable to watch, they were much more accomplished in their later lives. That is, those that were able to delay gratification were described as much more competent individuals by their parents. Moreover, in a later follow-up study, a correlation between SAT scores (an intelligence test for college entry in the US) and delaying gratification was found. Another study found differences in the brains of those people that delayed gratification. High delayers had more active prefrontal cortexes, which orchestrate goals, thoughts and actions, i.e. define people’s ability to plan and be disciplined. Studies even found correlations between delaying gratification and body mass index (BMI). 

The scientific workings of willpower were discovered later by Roy F. Baumeister. In one of his experiments, he led people into a room that smelled like chocolate and showcased a variety of cookies and other sweets. One group of participants was allowed to taste the chocolate, while the other group of participants was given radishes instead. Baumeister even notes in his research paper that people from the latter group starred at the displayed chocolate or even grabbed the cookies to smell them. Yet, this evil experiment didn’t end there. Baumeister had his participants solve a seemingly unrelated task afterwards: Solving a persistence-puzzle. Most interestingly, the group which had to try radishes made far less attempts in trying to solve the puzzle.

With this experiment, Baumeister laid the foundation for over 1200 subsequent studies on will-power and discovered one of the most important phenomena around the subject: ego-depletion. He explains: Willpower behaves like a muscle. Once it’s exercised, it depletes and needs time to regenerate. The group that had to eat radishes instead of chocolate used up their willpower as they had to exercise self-control to not eat the radishes. Afterwards, there was less willpower left when they tried solving the puzzle.

This finding triggered another alternative explanation of the marshmallow experiment. As you could see in the video, many of the children that made it used tricks that helped them to distract themselves. These tricks allowed them to circumvent the usage and thus the depletion of willpower. Many more studies afterwards, which focused on self-control, demonstrated this effect further, for instance by applying tricks to dieting. Tricking yourself into dieting is much more effective than doing it wilfully. The reason: ego-depletion. Baumeister’s book gives you a great introduction if you want to dig deeper.

The Science of Increasing Willpower

Now, what can we do to stop ego depletion, i.e. increase our willpower or let it last longer? A study conducted by two Australian psychologists Oaten and Cheng demonstrated that when students had to exercise more willpower, i.e. during exam period, they performed worse in laboratory willpower tests. Most interestingly though, the consequences reached far beyond ordinary laboratory experiments. Students started wearing dirtier clothes, stopped exercising, smoked more cigarettes. Even junk food was consumed up to 50% more times. These students weren’t doing all of this to save time. In fact, they reported they felt more eager to go out with friends. Some students even reported worse studying habits during the exam period — exactly the opposite of what one would expect. Moreover, students overslept and spent money more impulsively. 

In short, depleted ego amplifies feelings — and consequently, cravings will feel stronger than ever. How does this stop? Muraven found out that money does the trick: Subjects performed bad in his perseverance exercises that evolved strong elements of ego depletion. However, when people could win money, willpower suddenly seemed to spark again. More generally, incentives work wonders, even if they were set by ourselves. 

Other studies show that you should focus on one project at a time. Focussing on multiple ones depletes your willpower quicker and additionally makes you less productive. Focussing on one goal at a time may help you to preserve willpower longer. And enjoying making decisions does so, too. However, only in the short term, a study finds. People who enjoyed making decisions didn’t deplete their egos as fast in the short term — for approximately 4 minutes — but just as much in the long term — after approximately 12 minutes. 

The last trick stems from one of the most famous and thought provoking experiments around willpower. In a striking study, judges were investigated on their likeliness to make courageous decisions, such as acquitting former prisoners. In the morning, they made courageous decisions in approximately 65% of cases. The number dropped to 0 (!) until lunch and averaged 65% afterwards. Why the sudden change? As you might have guessed already after consuming so many experiments on ego depletion, their willpower exhausted after making several hard decisions. Interestingly, they restored their willpower by eating a sandwich. Indeed, glucose supply seems to help the brain to regenerate willpower. This also explains why you crave sugary food during difficult, stressful periods in your life. Moreover, taking time off does the same trick. After one to two hours of having a break, your willpower should be restored.

The main takeaways from this section are

Rethink your daily structure. Are you performing tasks that deplete your willpower but could be avoided? Are you performing tasks in the evening that require willpower and should instead be done in the morning? Adjust your day so that it makes sense considering ego-depletion. A good rule of thumb is: Start with the most challenging task in the morning. And: If it’s late in the evening or you know your willpower is depleted, don’t start any challenging task at all. The effects might be much more detrimental than simply postponing it. This is also how Google X operates and identifies the most important tasks to start with. Usually, but not always, the tasks that cost you more willpower are also more important. Postponing them until later during the day weakens the quality of your delivery. You do not want to do this with your most important tasks.

Motivate yourself by setting yourself goals and giving yourself proper rewards in case you reach those goals. Those can reach from you allowing yourself to take the evening off with your partner to allowing yourself to eat some tasty ice cream. Reaching goals has another great advantage on the side: It triggers dopamine, which helps your brain form neurons ten times as fast and thus considerably amplifies your learning output. 

Focus on one thing at a time. Focus doesn’t only help you to preserve willpower longer, it also makes you happier, healthier and more productive.

Enjoy what you are doing. There is fun to be found in everything, as daunting or irrelevant as the task might seem. Mihály Csíkszentmihályi describes in his book how people found enjoyment in assembly line work, gardening and intellectually stimulating tasks. It’s about the story you tell yourself, the lens through which you look at things and the attitude with which you tackle your tasks. 

Have a break. After a challenging task or a series of challenging tasks, take some time out. In the short term, this might look like being less disciplined, but it renders your system of productivity more sustainable. In the long term, you will benefit from being able to stay always disciplined when you need to. If this should not be the case, do longer breaks.