We often joke about being tired and hungry, or how we can’t function without our daily (or often twice daily) coffee. But fatigue is no laughing matter – being tired and hungry can deplete our cognitive resources and significantly affect our decision-making.

A well-known and disconcerting studying on the effects of fatigue on decision-making examined the factors that most influenced whether eight Israeli judges granted or denied parole requests. Researchers identified that, immediately following meals, about 65% of parole requests were granted, but that rate dropped steadily between meals, nearly reaching zero when the judges were most hungry. A second study recently identified a related effect – doctors are more likely to prescribe unnecessary antibiotics (commonly considered an “easy treatment option”) later in the day, when they are fatigued.

In order to combat the ubiquitous and pervasive effects of cognitive depletion, we must be aware of the extent of its effect on our decision-making and also design institutional structures so that decision-makers avoid making major choices when they are fatigued. Simple solutions like taking breaks and providing snacks to replenish decision-makers’ mental capacity can be effective ways to mitigate cognitive depletion.

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