Three men serving time in an Israeli prison appear before a parole board. The three prisoners have completed most of their sentence, but the parole board grants freedom to only one of them. Can you guess which one?
- Case 1 (heard at 8:00 a.m.): An Arab Israeli serving a 36-month sentence for fraud
- Case 2 (heard at 2:30 p.m.): A Jewish Israeli serving a 12-month sentence for theft
- Case 3 (heard at 4:40 p.m.): An Arab Israeli serving a 32-month sentence for fraud
Researchers analyzing more than 1,100 such cases over the course of a year discovered a troubling pattern to these decisions—and it wasn’t related to the prisoners’ crimes or sentences. On average, judges approved parole in about a third of the cases—but the probability of being paroled early in the morning or directly after a break was nearly seven times greater than late in the day or just prior to a break. (Danziger, 2010). This phenomenon is known as “decision fatigue,” and it negatively affects the judgment of just about everyone regardless of occupation or demographic (Tierney, 2011, para. 1–4).
In essence, the more decisions you make throughout the day, the harder each one becomes for the Slow Brain to process. Eventually, the Fast Brain takes over to conserve energy. In its quest for shortcuts, the Fast Brain either becomes reckless (acting impulsively instead of expending the energy to think through the consequences) or ducks a decision all together (Tierney, 2011, para. 5).
In the course of a day, project managers make thousands of decisions. Should I read check this email? How should I respond to this request? What should I work on next? As the brain depletes, we become more susceptible to impulsive decisions. We may abandon a difficult but important task to attend to an easier one. We may stop to chat with a co-worker rather than tackle a looming deadline. In some people, mental fatigue manifests itself as a crippling inability to do anything at all.