Decision fatigue
Decision fatigue and the state of the person deciding
By Dermot Rock
Osteopath and doctoral researcher in Human Performance and Innovation, University of Limerick
Updated
Decision fatigue is the drop in decision quality that follows a long run of demanding choices. People start to defer, default or decide on impulse.
The idea became famous through a study of parole rulings and a theory that willpower runs out like fuel. Both have since been challenged.
What holds up better is narrower and more useful. How well you decide depends partly on the physical state you decide in, and that state can be measured.
This guide covers the signs and causes, what the research does and does not show, and what founders can do about it.
What decision fatigue looks like
Cleveland Clinic describes decision fatigue as a phenomenon rather than a diagnosable condition. The more decisions a person makes in a day, the more depleted they become, and their judgement suffers.
Common signs
- Putting decisions off, or avoiding them altogether
- Impulsive choices made with less care than usual
- Physical, mental and emotional exhaustion
- Brain fog and losing the thread of conversations
- Irritability over small questions
- Feeling overwhelmed by what is still to decide
- Regret or rumination after a decision is made
- Physical symptoms such as tension headaches
Cleveland Clinic notes that decision fatigue is usually short-lived. If these signs appear every day, something more chronic may be going on, and it is worth raising with a clinician.
What causes decision fatigue
Cleveland Clinic lists five conditions that make decision fatigue more likely. Most of them describe an ordinary week for a founder. Physical state is a sixth, covered in more detail below.
Frequent decisions
Many choices in a single day, large and small, with little time between them.
Decisions that affect other people
Choices that land on a team, investors or family, where the cost of getting it wrong is shared.
Uncertainty
Deciding without enough information, or when no option is clearly right.
Difficult circumstances
Periods of strain such as a crisis, a fundraise or a major life event.
Perfectionism
Treating every choice as one that has to be exactly right.
Physical state
Short sleep and sustained stress change how well demanding decisions are made, as the physiology section below explains.
Researchers are still defining the concept. A 2018 review of 17 studies in the Journal of Health Psychology grouped its causes into three themes: the decisions themselves, the effort of self-regulation, and the situation the person is in.
What the evidence shows, and what it does not
The best-known study, published in PNAS in 2011, tracked parole rulings through the day. Favourable rulings fell from about 65% to nearly zero within each session, then returned to about 65% after a food break.
It became the standard illustration of decision fatigue. It is also contested.
Later that year, researchers who examined the same data reported that case order was not random. Prisoners without lawyers usually came last in each session, and they succeeded 15% of the time, against 35% for prisoners with counsel. Order, rather than hunger, may explain much of the pattern.
The theory behind it holds that self-control draws on a limited resource that runs down with use. In its largest test, a preregistered replication across 23 laboratories and 2,141 participants, the effect was close to zero.
None of this means tired people decide as well as rested ones. It means the popular explanation is weaker than its reputation, and a better one is needed.
What the willpower story leaves out
The willpower story treats decision fatigue as a mental fuel tank. A more grounded view looks at the body doing the deciding.
Sleep is the clearest case. A 2010 review of sleep deprivation research found the most consistent effects were slower, more variable attention. Rule-based reasoning held up relatively well. Flexible, creative and innovative thinking, and decisions that draw on emotion, were more likely to suffer.
Those are the decisions founders are paid to make.
Stress physiology matters too. A widely cited 2009 review linked higher heart rate variability, a measure of how the nervous system regulates the heart, with better performance on tasks that depend on the prefrontal cortex. It proposed that both reflect the same system of self-regulation.
Heart rate variability is not a measure of judgement, and a wearable score is not a diagnosis. Tracked over time and read alongside sleep, workload and how decisions actually turned out, these signals can show when the person deciding is likely to be at their best, and when they are not.
What to do about it
Most advice says to make fewer decisions. That helps, but it treats the decision as the problem and leaves the decider out.
Schedule the consequential decisions
Put the choices that matter most where your state is best, rather than wherever a gap appears in the calendar.
Remove trivial choices
Defaults, routines and delegation cut the number of small decisions competing for the same attention.
Protect sleep before big calls
Treat a short night before a board meeting, a hire or a negotiation as a risk to the decision.
Learn your own signs
Notice when you start deferring, defaulting or snapping. Those are signals that the next decision may be worse than it should be.
Measure instead of guessing
Sleep, recovery and stress load can be tracked. Over months, the data can show patterns that are hard to see from the inside.
Common questions
Is decision fatigue real?
The experience is widely reported, and Cleveland Clinic describes it as a phenomenon, though not a medical diagnosis. The mechanism is less settled. The best-known evidence, the parole study and the ego depletion theory, has been challenged, so it is best treated as a real experience with an uncertain explanation.
What causes decision fatigue?
Cleveland Clinic lists frequent decisions, decisions that affect other people, difficult life situations, uncertainty and perfectionism. Physical state plays a part too. Research on sleep loss shows it degrades flexible thinking and emotionally loaded decisions more than rule-based ones.
What are the symptoms of decision fatigue?
Common signs include putting decisions off, impulsive choices, exhaustion, brain fog, irritability, feeling overwhelmed, regret after deciding and physical symptoms such as tension headaches.
How do you recover from decision fatigue?
Cleveland Clinic notes that true decision fatigue usually passes within a day or so. Rest, sleep and fewer low-value choices help. If the signs persist every day, speak to a healthcare provider, because something more chronic may be involved.
Everything gets diligence except the person doing the diligence
Decision Athlete is a private clinical practice for founders. I measure, monitor and manage the physiology behind your decisions, so the person making the company's largest calls is maintained like any other critical asset.
About the author
Dermot Rock qualified as an osteopath in 2011 and has worked in strength and conditioning since becoming a certified strength coach in 2007. He served as an army officer and studied innovation at the University of Galway.
He is undertaking doctoral research in Human Performance and Innovation at the University of Limerick, asking to what extent decision-making readiness can be determined as a physiological construct. Decision Athlete is where he investigates that question in practice.
Sources
- Danziger S, Levav J, Avnaim-Pesso L. Extraneous factors in judicial decisions. PNAS, 2011.
- Weinshall-Margel K, Shapard J. Overlooked factors in the analysis of parole decisions. PNAS, 2011.
- Hagger MS, Chatzisarantis NLD, et al. A multilab preregistered replication of the ego-depletion effect. Perspectives on Psychological Science, 2016.
- Killgore WDS. Effects of sleep deprivation on cognition. Progress in Brain Research, 2010.
- Thayer JF, et al. Heart rate variability, prefrontal neural function, and cognitive performance. Annals of Behavioral Medicine, 2009.
- Pignatiello GA, Martin RJ, Hickman RL. Decision fatigue: a conceptual analysis. Journal of Health Psychology, 2018.
- Cleveland Clinic. 8 signs of decision fatigue and how to cope. 2023.
This guide is general information, not medical advice. Read the medical disclaimer.