At the end of a tiring day, you come home alone (or with your spouse/partner). You don’t even have the energy to set the table, let alone prepare dinner. Around your home, there are three restaurants that fit your budget and standards and deliver to your door. One is a Chinese restaurant with salty and greasy dishes that make your mouth water just thinking about them; another is an Italian restaurant that tempts you with cheesy, fully loaded pizzas; and the third is a small bistro with a healthy eating concept, offering freshly prepared salads and whole-grain sandwiches. Which one would you choose?
Now, here’s another question you might wonder “what does this have to do with anything?”—Would this choice be the same as the one you’d make on a calm afternoon spent reading a book on your balcony during the weekend?
Most people, after a tiring day, tend to choose the tempting foods with fat and flavor rather than healthy ones. As a result of evolution, human genes are programmed to enjoy sugary and fatty foods. This trait, which was essential for survival in a world where food was scarce, has become a threat to human health today, where high-fat and sugary foods are easily accessible. Even though our conscious self (rational-thinking brain) tries to resist the appeal of fat and sugar, our impulsive side (emotional-feeling brain) dominates during times of fatigue or stress, leading us to consume unhealthy foods (junk food). This is why many diets fail after a stressful experience or a tiring day.
Ego Depletion
The concept of “ego depletion” can be compared to the “brake failure” term used for cars from the previous generation of the automotive industry. Ego depletion describes the state in which the thinking brain (ego), which tries to restrain impulses from the emotional brain, loses its resistance against pleasurable stimuli. We can compare human willpower to muscles: just as lifting weights continuously tires muscles until they can no longer lift, resisting tempting stimuli consumes significant energy, eventually leaving the person unable to resist.
A group of scientists from Stanford University studied whether people’s rational and willful brain (thinking brain) becomes more easily tempted when mentally occupied. To do this, they mentally engaged the brain and measured its resistance to tempting stimuli. Researchers Baba Shiv and Sasha Fedorikhin divided participants into two groups: one was asked to memorize a two-digit number, and the other a seven-digit number, and repeat it to a research assistant in a room at the end of the corridor. While walking and trying to remember the numbers, participants passed two sets of snacks on a table: chocolate cream cakes in the first row, and colorful, healthy fruit cups in the second. They were told they would earn the snack after correctly recalling the number but had to choose beforehand.
Those memorizing the two-digit number were much more likely to choose the healthy fruit cup compared to those memorizing the seven-digit number. Those who had to use higher brain functions more intensely to remember the seven-digit number found it harder to resist their impulses and opted for high-calorie foods. This clearly explains why this is called ego depletion. This study shows that when the human mind is consciously and intensely engaged, the system controlling impulses has a greater impact on behavior (1).
Another interesting study on ego depletion relates to the justice system (2). When examining cases involving parole decisions in the U.S., it was found that judges were more likely to grant parole at the beginning of the day and right after breaks, while denials increased as fatigue set in and lunchtime approached. Similarly, a study of 1,112 parole decisions by eight Israeli judges over ten months showed that the probability of granting parole was around 65% at the beginning of the day or right after lunch breaks but dropped to almost zero as fatigue increased and lunchtime neared (3).
Normally, judges should carefully examine details before granting parole. However, after a series of back-to-back cases that tire them, they tend to take the easier route and deny parole. These findings may also apply to various competition juries and academic panels. Perhaps this is why, unknowingly, candidates in academic exams often offer juries snacks of sweet and savory foods.
Willpower is a Depleting Resource
Self-control is a fundamental skill that keeps one’s heart, body, and mind away from immediately gratifying temptations. In everyday language, self-control is referred to as willpower. Willpower is a uniquely human capacity that guides one’s thoughts, emotions, and behaviors.
Willpower relies on a limited internal resource. The longer one exerts self-control, the more likely ego depletion becomes (3). Therefore, in environments rich with emotionally triggering stimuli, constantly trying to control oneself eventually exhausts this resource.
In another study (4), participants were told they would undergo a taste test. In the test room, one plate contained appetizing, steaming chocolate cookies, and another plate contained radishes. One group was asked to eat only the cookies, the other only the radishes, avoiding the other plate. The real aim was to test their willpower by leaving them alone in the room. Observations showed none broke the rules. Later, participants were told they would complete a second task measuring problem-solving skills. They were given an unsolvable maze. The cookie-eating group, whose willpower had not been tested, worked on the maze for an average of 19 minutes and made 34 attempts. In contrast, the radish-eating group, whose willpower had been strained by resisting the cookies, worked only 8 minutes on average and made 19 attempts. This experiment demonstrates that even simple tests of self-control deplete the thinking brain’s energy. Different parts of our brain control the “go” and “stop” commands. People we describe as having “strong willpower” often have a well-functioning “stop” mechanism. This enables control and regulation of primal impulses, allowing the individual to focus energy and attention on long-term and more valuable goals.
Conclusion
When our willpower weakens, we struggle more to restrain our desires. This also leads to backsliding on rule-following and keeping promises, and lowers honesty levels. In other words, mental and physical fatigue makes it easier for a person to distort reality to suit themselves and stray from the right path. Therefore, ensure that new activities added to your daily routine do not deplete your willpower quota. Avoid making important decisions when tired or stressed, and if possible, postpone decision-making to a time when you feel more relaxed.
(*) This article has been adapted from the book “Decisions Bear the Penalty of Foolish Emotions.”
Source
- Ariely D. The (honest) truth about dishonesty. HarperCollins Publishers; 2012.
- Danziger S. Levav J, Avnaim – Pesso L. Extraneous factors in judicial decisions. Proceedings of the National Academy of Sciences of the USA 2011.
- Inzlicht M, Schmeichel BJ. What is ego depletion? Perspectives on Psychological Science 2012; 7(5): 450-463.
- Baumeister RF ve ark. Ego depletion: is the active self a limited resource. Journal of Personality and Social Physiology 1998; 74(5): 1252-1265.
