Is Decision Fatigue Real?

One of Barack Obama’s self-proclaimed secrets to success is a fine-tuned routine of daily habits. He avoids making trivial decisions to preserve mental energy and decision power. During his presidency, Obama followed strict workout schedules and instead of agonising over outfit choices, he only ever wore two different kinds of suit: blue or grey. By cutting down on unimportant decisions, he made a conscious effort to preserve his energy for the important ones, like how to reform the U.S. healthcare system or whether to send additional troops to Afghanistan.

Obama isn’t the only person who swears by this strategy. Facebook co-founder Mark Zuckerberg famously wears the same grey t-shirt to work every day, stating he doesn’t want to waste his energy on “things that are silly or frivolous." He believes that by cutting down unnecessary choices, he can maximise personal efficiency.

What Is Decision Fatigue?

Obama and Zuckerberg created professional decision strategies to combat a phenomenon commonly referred to as decision fatigue, which is based on the idea that decision power is a limited resource that becomes depleted over time. It’s assumed that, similar to a muscle that tires with exercise, the human mind tires with repeated decision making—especially if the decisions in question are challenging. Consequences of decision fatigue are thought to include poorer choices that are susceptible to bias and lack self-control. In some cases, it might lead to decision-makers avoiding to make a choice or struggling to reach a decision even after a period of deliberation.

A large body of research has provided evidence for decision fatigue and highlighted areas of decision making in which the phenomenon might be particularly problematic. One such area is the healthcare sector, where doctors’ decision-making quality can have life-changing consequences for their patients. For example, a study investigating nurses’ choices at a medical helpline found that decisions became more conservative and less efficient the more time elapsed since their last break. Similarly, a study of surgeons’ decisions to operate found that patients with appointments toward the end of a long work shift were less likely to be scheduled for surgery compared to those at the beginning of a shift.

Is Decision Power a Limited Resource?

Did reading the last paragraph tempt you to reschedule your next medical appointment from evening to morning? If so, hold your fire for a moment and read on.

Previous evidence on decision fatigue has recently been re-examined and challenged. Indeed, a rigorous meta-analysis of 116 experiments using various different decision tasks found no evidence for depletion of self-control. This finding questions the notion that decision power or self-control are limited resources that can be used up over time. One reason for the previous over-estimation of decision fatigue may be the so-called publication bias. This describes the well-established fact that it’s easier to publish research studies in support of interesting phenomena as opposed to those which offer inconclusive or negative results.

Instead of being an objective, universal phenomenon, what's referred to as decision fatigue might be confounded by other contextual factors. For example, if healthcare providers make poorer choices as the day goes by, this could simply be explained by delays in their appointment schedules, leading them to rush decisions with the aim of finishing work on time. While this is bad news for affected patients, we might be able to address the issue by spacing out appointments more efficiently.

Some researchers have even suggested the existence of a self-fulling prophecy: Those individuals who believe in a limited capacity for good decision making and willpower may be the only ones to experience it.

How to Interpret the Evidence?

With mixed research findings on decision fatigue, it’s hard to know how to adapt your personal behaviour. Should you avoid making important decisions later in the day? Is it necessary to replace your beautifully multi-coloured wardrobe with 20 plain old t-shirts of the same make?

Just as with clothing choices, a one-size-fits-all approach is unlikely to work in decision making. While limiting trivial choices may undoubtedly save you time and thus increase efficiency, strict routines may feel boring, restrictive, or impossible to some. (As a working mum of two, I can vouch for that.)

Instead, why not pay attention to your personal decision-making habits and address issues as they arise? You might notice more impulsive choices at a certain time of day. Perhaps you struggle with your self-control when you’re tired, rushed, or just a little grumpy? If so, it could help to re-design your choice environment or postpone decisions for when you’re feeling up to them.

Self-Control Essential Reads

On Hold or in Overdrive: Decoding Inaction and Impulsivity

Does Performing Rituals Build Character?

In any case, believing in a limited amount of decisiveness or willpower is hardly going to be helpful. If you’re convinced that you’ve used up all your self-control, how are you meant to resist any further temptation? Let’s re-think the muscle metaphor from the beginning. Instead of picturing the mind as tiring with repeated choice, let’s imagine a muscle that grows stronger with each challenge and each opportunity for exercise.