Turns out it's not you it's crazy about. It's all of us. Psychologist Roy F. Baumeister's research reveals that there are limits to how many good decisions we can make in the course of a day. The more decisions, big or small, we have to make, the worse they get. And at the end of the day, we've all typically made an endless amount of decisions, all of which drain our willpower.

Your willpower muscle gets tired

According to research, our willpower and self-control come from a limited reservoir. And the more you use it, the more it weakens. It is according to Baumeister, that's why you put chocolate in the shopping cart at the end of a long shopping trip, that's why judges grant fewer paroles late in the day and therefore subjects can hold a hand in ice water for a shorter time if they have just before had to resist a cookie rather than a radish. And not least that is why your frequency of visits to Facebook, YouTube, Twitter or [insert your favorite skipping action] becomes more frequent in the afternoon. Your willpower muscle has simply tired.

It's not even just making decisions that drains your self-control and willpower. Eg. taper regulating attention, regulating emotional responses, considering a choice, overcoming muscle fatigue, resisting temptation (eg the cake mentioned earlier), accepting risk and breaking a habit energy from the same reservoir.

Baumeister, who pioneered research in this area, named the phenomenon "decision fatigue", which can probably be translated as something like decision fatigue. His test of the phenomenon involved e.g. asking subjects to refrain from showing emotion while watching a tearjerker of a film. Subjects who had suppressed their emotions gave up more quickly in willpower tests, where they, for example, had to solve geometric puzzles than people who had given their emotions free rein.

How to combat decision fatigue

As a manager, this phenomenon is perhaps extra frustrating because in your job you depend on the decisions you make being of the highest quality. Fortunately, there are things you can do yourself to reduce your decision fatigue and make more of the good, sensible kind of decisions.

Tips to avoid decision fatigue:

1. Avoid temptations. If you are not exposed to temptation, you use less of your willpower reservoir. A classic example of an experiment that illustrates this was conducted with children. They were placed in front of a marshmallow and told that if they left it, they would later get two marshmallows. Here, the children who looked away from the marshmallow or closed their eyes did better than the children who stared directly at it. The same mechanism applies to adults.
2. Be prepared. Make sure you have a solution ready for when you get into situations where you know you will be tempted and your willpower put to the test. Eg. if you're trying to drink less alcohol, make a plan a la: "Next time I'm offered a drink, I'll ask for a sparkling water".
3. High motivation can strengthen your willpower. If you really want something or can see that what you're doing (or not doing) is helping a cause you're passionate about, your willpower seems to increase.
4. Train your willpower. Some experts compare your willpower to a muscle that gets tired with use. The comparison also holds when looking at how you respond to training. Just like your muscles, your willpower gets stronger through exercise. As a side benefit, there is research that suggests that if you train your willpower in one area, it will be strengthened in other, unrelated, areas. If you e.g. goes to the gym three times a week (an action that requires willpower until it becomes a habit), then research shows that you e.g. while making better food choices.
5. An even blood sugar level. Your willpower is affected by your brain's blood sugar level. When the level is low, which i.a. becomes of making decisions, your willpower weakens. To give your willpower the optimal conditions, you should therefore frequently eat small, healthy and filling meals.
6. Focus on one area at a time. If there are several areas where you e.g. want to change habits, it is best to focus on one area at a time, rather than on a whole list. This means a lower consumption of willpower and thus a greater chance of success.

Source: American Psychological Association: What You Need to Know About Willpower, The Psychological Science of Self-Control