In decision making

Decision making

Decision making can be regarded as the mental processes resulting in the selection of a course of action among several alternative scenarios. Every decision making process produces a final choice. The output can be an action or an opinion of choice.- Overview :Human performance in decision terms...

 and psychology

Psychology

Psychology is the study of the mind and behavior. Its immediate goal is to understand individuals and groups by both establishing general principles and researching specific cases. For many, the ultimate goal of psychology is to benefit society...

, decision fatigue refers to the deteriorating quality of decisions made by an individual, after a long session of decision making. It is now understood as one of the causes of irrational trade-offs in decision making. For instance, judges in court have been shown to make poorer decisions later in the day. Decision fatigue may also lead to consumers making poor choices with their purchases.

There is a paradox in that "people who lack choices seem to want them and often will
fight for them"; yet at the same time, "people find that making many choices can be [psychologically] aversive."

Reduced ability to make trade-offs

Trade-offs, where either of two choices have positive and negative elements, are an advanced and energy-consuming form of decision making. A person who is mentally depleted becomes reluctant to make trade-offs, or makes very poor choices. Jonathan Levav at Stanford University

Stanford University

The Leland Stanford Junior University, commonly referred to as Stanford University or Stanford, is a private research university on an campus located near Palo Alto, California. It is situated in the northwestern Santa Clara Valley on the San Francisco Peninsula, approximately northwest of San...

 designed experiments showing how decision fatigue can leave a person vulnerable to sales and marketing strategies designed to time the sale. "Decision fatigue helps explain why ordinarily sensible people...can't resist the dealer's offer to rustproof their new car."
Dean Spears of Princeton University

Princeton University

Princeton University is a private research university located in Princeton, New Jersey, United States. The school is one of the eight universities of the Ivy League, and is one of the nine Colonial Colleges founded before the American Revolution....

 has argued that decision fatigue caused by the constant need to make financial trade-offs is a major factor in trapping people in poverty. Given that financial situations force the poor to make so many trade-offs, they are left with less mental energy for other activities.

Decision paralysis

Decision fatigue can result not only in fast and careless decisions but even in decision paralysis, where no decision is made at all. Research by Iyengar and Lepper
(2000) "found that people who had more choices were often less willing to decide to buy anything at all, and their subsequent satisfaction was lower when they had been confronted with 24 or 30 options than when they faced six options"; which "suggest[s] that choice, to the extent that it requires greater decision-making among options, can become burdensome and ultimately counterproductive." In the formal approach to decision quality management, specific techniques have been devised to help managers cope with decision fatigue.

Impulse purchasing

Decision fatigue can influence irrational impulse purchase

Impulse purchase

An impulse purchase or impulse buy is an unplanned decision to buy a product or service, made just before a purchase. One who tends to make such purchases is referred to as an impulse purchaser or impulse buyer...

s at supermarkets. During a trip to the supermarket, trade-off decisions regarding prices and promotions can produce decision fatigue, hence by the time the shopper reaches the cash register, less willpower remains to resist impulse purchases of candy and sugared items. Sweet snacks are usually featured at the cash register because many shoppers have decision fatigue by the time they get there. Florida State University

Florida State University

The Florida State University is a space-grant and sea-grant public university located in Tallahassee, Florida, United States. It is a comprehensive doctoral research university with medical programs and significant research activity as determined by the Carnegie Foundation...

 social psychologist Roy Baumeister

Roy Baumeister

Roy F. Baumeister is Francis Eppes Professor of Psychology at Florida State University in Tallahassee, Florida. He is a social psychologist who is known for his work on the self, social rejection, belongingness, sexuality, self-control, self-esteem, self-defeating behaviors, motivation, and...

 has also found that it is directly tied to low glucose

Glucose

Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...

 levels, and that replenishing them restores the ability to make effective decisions. This has been offered as an explanation for why poor shoppers are more likely to eat during their trips.

Researcher Carol Dweck found "that while decision fatigue does occur, it primarily affects those who believe that willpower runs out quickly." She states that "people get fatigued or depleted after a taxing task only when they believe that willpower is a limited resource, but not when they believe it's not so limited". She notes that "in some cases, the people who believe that willpower is not so limited actually perform better after a taxing task."

Impaired self-regulation

The "process of choosing may itself drain some of the self’s precious resources, thereby leaving the executive function less capable of carrying out its other activities. Decision fatigue can therefore impair self-regulation". "[S]ome degree of failure at self regulation" is at the root of "[m]ost major personal and social problems", such as debt, "underachievement at work and school" and lack of exercise.

Experiments have shown the interrelationship between decision fatigue and ego depletion

Ego depletion

Ego depletion refers to the idea that self-control or willpower is an exhaustible resource that can be used up. When that energy is low, mental activity that requires self-control is impaired. In other words, using one's self-control impairs the ability to control one's self later on. In this...

, whereby a person's ability for self-control against impulses decreases in the face of decision fatigue.

George Loewenstein has suggested that the disastrous failure of men in high office to control impulses in their private lives may at times be attributed to decision fatigue stemming from the burden of day-to-day decision making. Similarly, Tierney notes that "C.F.O.'s [are] prone to disastrous dalliances late in the evening", after a long day of decision-making.

Research shows the decisions judges make are extremely influenced by how long in the day it has been since their last break.