Raisin Bran or Honey Nut Cheerios? Standing in front of the pantry, faced with five boxes of cereal, I was paralyzed with indecision. I could not for the life of me choose which one to have when I got home from my overnight shift. It was completely ridiculous: I had just spent nine hours effortlessly making, in some cases, literally life-and-death decisions in the ER, and now I pathetically could not pick among a few not-terribly-different, nutritiously marginal, food-like products.
It turns out, I was suffering from what has been termed “decision fatigue.” Some really innovative and fascinating behavioral and neuroscience research in recent years has shed light on what is a common phenomenon, and one with widespread implications. Perhaps the most famous study is one of parole decisions by Israeli judges: investigators analyzed over 1100 cases in a ten month period. One of the strongest predictors of granting parole was when in the day the case was reviewed. Prisoners whose cases were heard at the start of a session had a roughly 65% chance of being granted parole, whereas parole was almost never granted to the last cases reviewed. Parole was far more likely at the start than the end of a session even after controlling for severity of the crime, length of time served, prior criminal history, and ethnicity.
Other research has demonstrated that after a period of repeated decision-making, subsequent decisions become harder. This is manifest as either indecisiveness (e.g., Raisin Bran or Cheerios), or deferring a decision by defaulting to the fall-back position (e.g., not granting parole). Not only do people with decision fatigue find it hard to make choices, they also show decrease in willpower, leading to bad choices. It’s why we often eat or drink too much at the end of a tough day. These findings are consistent with a theory first proposed by Freud, known as “ego depletion.” In essence, voluntary mental effort, including making choices and resisting urges, draw on a pool of mental energy. When that pool is drained, quality of mental efforts is diminished. Intriguingly, food plays a role; decision fatigue is ameliorated by glucose. (It’s not just the act of eating – artificial sweeteners do not have the same effect.) For example, parole rates for the Israeli prisoners went up after a morning snack, then drifted down again before lunch. And back up again after lunch!
The notion of decision fatigue has numerous implications. Most obvious is for the way we do our work. Intellectual performance falls off after a period of time. Potential remedies include frequent breaks; spreading meetings requiring decision-making over the course of a day rather than stacking them back-to-back; not trying to make critical decisions when you are mentally tired or hungry.
Another implication is a societal one. Self-control is at a low point when ego depletion sets in. Poor people, who frequently have to make trade-offs that those with more means don’t have to worry about, may be more prone to this. They make more, and more challenging, decisions in a given day than others. Choices that may seem trivial or irrelevant to me are depleting to someone who is counting every dollar. Studies suggest that poverty is not caused by bad choices; rather, bad choices are a consequence of living in poverty. But we are all potential victims. It’s one of the reasons supermarkets put all that candy at the checkout line. It turns out, shoppers who have just spent a half hour choosing among a dazzling array of products are much more prone to give in to the temptation. (It’s also why, for example, car salesman offer the ridiculous undercoat protection after you’ve had to select the model, color, interior décor, sound system, and various other options.)
Well, picking a cereal for breakfast this morning was easy. But deciding on dinner is going to be a challenge.