Is decision fatigue affecting your work?

Have you ever found yourself getting really irritable in the afternoon?

Maybe making poor decisions, or even worse, putting off making decisions?

Have you ever checked your work from the day before and thought ‘what was I thinking’.

Chances are that if any of these things have happened to you, then you might be experiencing some form of ‘decision fatigue’.

Decision fatigue helps explain why ordinarily sensible people get angry at colleagues and families, splurge on clothes, or head to the local shop around the corner from the office and buy junk food. No matter how rational you try to be, you can’t make decision after decision without paying a biological price. It’s different from ordinary physical fatigue — you’re not consciously aware of being tired — but you’re low on mental energy

So what is decision fatigue?

I want you to imagine for a second that your brain is a vault. Every morning when you wake up the vault is replenished with a stack of shiny gold coins.

Every time you make a decision, or resist an urge (willpower/self-control) then one of the gold coins is taken away. On a particularly demanding day (back to back meetings, or technical projects) then it stands to reason that you run out of gold coins quicker. This process of running out of gold coins is what is known as ‘decision fatigue’.

It’s important to understand that the choices we make during the day have a compound effect on our ability to make decisions later on, especially when involving self-control. The more choices we make throughout the day, the harder each one becomes for our brain, and eventually it looks for shortcuts, in one of two very different ways.

One shortcut is to become reckless: to act impulsively instead of expending the energy to first think through the consequences. The other shortcut is the ultimate energy saver: do nothing. Instead of agonizing over decisions, avoid any choice. Neither of these shortcuts are going to lead to a productive day at the office. It also explains why code-checking or data analysis are tasks best completed earlier on in the day.

Your brain does not stop working when glucose is low. It stops doing some things and starts doing others. It responds more strongly to immediate rewards and pays less attention to long-term prospects.

Can I stop myself from getting decision fatigue?

Research has shown that the brain, like the rest of the body, extracts energy from glucose, the simple sugar manufactured from the majority of foods that we eat. It makes sense that if you top up your brain with some simple sugar then this will enable you to carry out further tasks without experiencing decision fatigue.  

This theory has been corroborated multiple times. In one piece of research, scientists tried refueling the brain in a series of experiments involving lemonade which was mixed with either sugar or with a diet sweetener.

The sugary lemonade provided a burst of glucose, the effects of which could be observed right away in the lab; the sugarless variety tasted quite similar without providing the same burst of glucose. Again and again, the sugar restored willpower (reducing decision fatigue), but the artificial sweetener had no effect. The glucose would at least mitigate the depletion and sometimes completely reverse it.

The restored levels of glucose improved the subject’s ability to make decision, but also had an effect on their self-control. The results showed that those who had consumed the sugary lemonade (rather than the sugarless version with artificial sweetener) were able to resist irrational bias when making choices, and when asked to make financial decisions, they were more likely to choose the better long-term strategy instead of going for a quick payoff.

The discoveries about glucose help explain why dieting is a uniquely difficult test of self-control and impairs our decision making ability. It helps us to understand why people with phenomenally strong willpower in the rest of their lives can have such a hard time losing weight. They start out the day with virtuous intentions, resisting croissants at breakfast and dessert at lunch, but each act of resistance further lowers their willpower and increases their likelihood of decision fatigue.

So if I cancel all my meetings i’ll be ok?

Sadly avoiding mentally intensive aspects of work is not the answer. According to one study, people spend between three and four hours a day resisting temptations brought about by decisions.

We have no way to understand how our ancestors demonstrated self-control in the days before smart phones wifi, but it is more than likely that they were under less willpower-depleting strain. When there were fewer decisions, there was less decision fatigue. Today we feel overwhelmed because there are so many choices that we can make.

Our bodies may have dutifully reported to work on time, but our minds can escape at an instant. A typical computer user looks at more than thirty different websites on any given day and gets fatigued by the continual decision making — whether to keep working on a project, check out the oatmeal, read the orange rag or buy something on eBay.

No one has a gut-level sense of just how tiring it is to decide. Big decisions, small decisions, they all add up. Choosing what to have for breakfast, where to go on vacation, whom to hire, how much to spend — these all deplete willpower and reduce our decision effectiveness. There is no telltale symptom of when we are running low on gold coins in our vault. It is something that sometimes might be gradual over a day, or catch up with us from left field when we least expect it.

Decision fatigue manifests itself not as one feeling but rather as a propensity to experience everything more intensely. When the brain’s regulatory powers weaken, frustrations seem more irritating than usual. Impulses to eat, drink, spend and say stupid things feel more powerful.

What else can I do?

Studies show that people with the best self-control are the ones who structure their lives so as to conserve the amount of important decisions that they need to make. They don’t schedule endless back-to-back meetings. They avoid temptations like all-you-can-eat buffets, and they establish habits that eliminate the mental effort of making choices.

Instead of deciding every morning whether or not to force themselves to exercise, they set up regular appointments to work out with a friend. Instead of counting on willpower to remain robust all day, they conserve it so that it’s available for emergencies and important decisions.

That’s why the truly wise don’t restructure the company at 4 p.m. They don’t make major commitments during happy hour – and if a decision must be made late in the day, they know not to do it on an empty stomach.

In summary

During our working day we are subjected to a continuous barrage of decisions (both conscious and subconscious) that require our attention. Yet this comes at a cost to our mental wellbeing as the day wears on.

It’s also easier to understand what constantly making important decisions has on our bodies, as we deplete glucose stores and seek to replenish them. It makes sense that junk food (in particular sugary sweets and chocolate) become so appealing when we are tired or experiencing decision fatigue.

There are steps we can put in place to limit the effects of decision fatigue, and to improve our workplace activities without sacrificing on quality.  


This article was prompted after reading this article about why Mark Zuckerberg only wears grey t-shirts.

A lot of the studies and research mentioned in this article are referenced from this amazing piece on the  New York Times website about Decision Fatigue. If you find this post interesting i’d strongly recommend taking a look, just be warned it’s nearly 5000 words long!

I found additional information useful for this article contained in this report Decision Fatigue Exhausts Self-Regulatory Resources