• Joumana Elomar

Decision Fatigue: Why We Make Worse Decisions Later In The Day

Have you ever felt really tired after making a series of decisions? You reach the end of the day after making a big call and all you want to do is switch off. And yet, your dinner date asks "What should we have for dinner tonight?" and you groan internally at the idea of having to make yet another decision. If so, you might have experienced decision fatigue.


Decision fatigue is something we experience after we make many decisions. We see a sharp decrease in the quality of our decision-making. It's also one of the reasons we might feel overwhelmed when we have too many choices to make. Basically, the more decisions we need to make, the worse we are at weighing all the options which makes it harder to make a logical choice.


Mythbusting The Numbers

If we look around, we'll find many sources that say we make 35,000 decisions in a day but this is unsubstantiated. Having checked for the science, it seems the source is nowhere to be found. As there isn't an existing standardised scientific method for measuring and defining "decisions", it's difficult to say how many we make in a day.


The closest research-based statistic is a 2007 study on 'Mindless Eating' by researchers Brian Wansink and Jeffrey Sobal where they studied 150 people about the number of daily decisions they make on food and drinks. From this study, researchers found that the participants made on average 220 daily decisions about what they consumed. Interestingly, they seemed to only be aware of around 20 of them. So where does decision fatigue come from?


A Little History

Coined by social psychologist Roy F. Baumeister, decision fatigue is the mental and emotional strain that comes from making choices. In his words: "Basically, the idea is this... our ability to force ourself to do difficult things—that is, applying self-control or self-discipline—draws upon a certain limited resource within us. And when we’re forced to make tough decisions, it calls upon that same resource. So when our self-control runs low, we start to make poor choices."


Even professional decision-makers are prone to decision fatigue. In one study looking at 1,100 parole hearing decisions made by Israeli judges, the most telling factor of whether individuals were granted parole was surprisingly not their crime or background. It was when the judge last took a break. This shows the uncomfortable consequences of mental fatigue on important decision-makers. And it's not just our ability to choose between options that's impaired. It also impacts us by:

  1. Impairing ability to make trade-offs. We can think of decision-making like a balance or a scale where on each side we add up the pros and the cons. When we're energised, it's easy to do the mental acrobatics to weigh things up. When we're mentally depleted, it's difficult to focus and to think clearly about the positive and negative trade-offs.

  2. Increasing impulsivity. When we're tired, we're much more likely to be impulsive. As decision-fatigue is linked to our self-control, it can show up in our purchases, in our mood or in our behaviour e.g. We're much more likely to buy those last-minute snacks at the supermarket when we're mentally fatigued.

  3. Increasing our decision avoidance. When we're mentally exhausted, our brains look for ways to conserve energy. This includes avoiding decisions! Big or small, it pushes us to steer clear from having to make any more choices.

So what can we do about it?


Practical Strategies

When it comes to reducing decision fatigue, there are a few things we can do.

  • Make important decisions first. Try to schedule critical decision-making in the morning. This gives you the most energy to think through your decisions, reduces the possibility of impulsivity and leads to more logical choices.

  • Never make a decision when hungry: Studies show that glucose levels (the level of sugar in your blood) can impact your ability to make consistent decisions. So if you do need a little boost, have a snack to maintain your blood sugar levels and help prevent decision fatigue.

  • Reduce the number of decisions. Take an inventory of the decisions you make on a daily basis. Assess which ones are important to you and which ones you can reduce. For example, you can plan your meals in advance to reduce the number of times you need to think about cooking. You could wake up at the same time everyday or a schedule a consistent exercise time. You could take inspiration from big decision-makers like Obama and Steve Jobs who famously pared back their wardrobes. Experiment to find what works for you.

  • Change your mindset: Psychologist Carol Dweck found that how you see your willpower impacts how likely you'll be affected by decision fatigue. If you believe that willpower runs out quickly, then you're more likely to feel depleted after a taxing task. In her words, "We find that people get fatigued or depleted after a taxing task only when they believe that willpower is a limited resource, but not when they believe it’s not so limited". In fact, for the group that believed that willpower doesn't run out quickly they were more likely to experience a rush of energy after a taxing task!


Making decisionsbig or smallis a fundamental part of life. When we make lots of decisions, we can sometimes be so mentally fatigued that we lose our ability to make logical choices. Protecting ourselves from decision fatigue is not just important for our health but for the quality of our long-term decisions.

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