The brain literally loses the energy to think critically over time.
The brain’s energy capacity is not unlimited. Making solid, well-founded decisions comes at a cost of energy. The same thing happens every time we have to engage willpower to do (or not do) something we’d rather default to.
Decision Fatigue is sometimes referred to as “Ego Depletion”. And, unfortunately, we need the most help when we’re the least likely to get it - end of the day, or when weird circumstances pop up.
Repeated decision making drains our energy reserves more quickly. We start to mentally cut corners for all new decisions, and we don’t even realize it. We ignore inputs and signals, start to not make trade offs, and rely on biases.
Examples
- Judges are harsher around midday, just before their break (see also: 5 Principles of Breaks)
- Bill Clinton is ‘prone to making bad decisions when he’s tired”.