Decision Fatigue Is a Real Phenomenon

Your brain's capacity for making rational choices is a finite resource, much like a muscle that gets tired after a workout. This concept is closely related to the psychological theory of "ego depletion," which posits that acts of self-control and decision-making draw from a single, limited pool of mental energy. Every choice you make, from what to wear to a major business strategy, chips away at this reserve. As your energy wanes, your brain starts looking for shortcuts. Two common shortcuts are becoming reckless and impulsive, or simply avoiding a decision altogether by sticking with the default option.

This phenomenon was starkly illustrated in a famous study of Israeli judges ruling on parole cases. The researchers discovered a startling pattern linked not to the facts of the cases, but to the time of day. Prisoners who appeared before the judges early in the morning or immediately after a food break received parole about 65% of the time. However, as the day wore on, the approval rate for similar cases steadily dropped, plummeting to nearly zero by the end of a session. The judges weren't becoming intentionally harsher; their depleted minds were defaulting to the safer, easier choice—denying parole and maintaining the status quo. This highlights how crucial timing and mental energy are to the quality of our judgment.