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If you’ve ever done a renovation then you know that the best laid plans become more like rough road maps with unexpected detours. Contingencies always arise that knock you off course. You might discover a pipe in a wall where you had planned to put a recessed medicine cabinet or after you knocked down a wall you might discover a 3 foot-wide column that you thought would be only 10 inches wide. For every contingency that arises we have to make a decision on what to do. Sometimes there’s a clear winner among the options. But how often does that happen? Decisions can be tough, and they have consequences. How can we possibly know if we made the best decision?
So now, while doing a renovation, I have been having to make a series of difficult choices. Despite a tremendous amount of planning, a series of surprises happened. Decisions are needed by the contractor, suppliers, my husband, and others. On a recent day I started at 9 am and was pummeled by one decision after another. By noon I was already quite weary. By 4 pm, I was completely exhausted and the day wasn’t over yet.
Making a lot of decisions throughout the day is what knowledge workers experience on a daily basis.Knowledge workers typically are confronted with a slew of decisions: through email, in face-to-face decisions with colleagues, from admins, in meetings, in calls, in proposals, and in personal life. And of course, knowledge workers do much more than make decisions, which adds to their cognitive load.
When we’re exhausted, it changes the decision outcome
When we make decisions, we utilize mental resources: evaluating information and considering alternatives. When we do this process over and over again, it can wear down a person’s executive function and limited pool of cognitive resources. We have fewer mental resources to use in reasoning about the decision, and we’re mentally fatigued. It’s like climbing uphill when we’re already tired.
Researchers at the Sorbonne and Université Pierre et Marie Curie demonstrated how we become more impulsive in our decisions when we’re tired. They brought people to a psychology laboratory and gave them a series of hard tasks. The tasks that the subjects performed was called an “n-back” task. In the task, subjects were told to listen to a stream of numbers and then were asked to recall the third number back from the one they just heard. The numbers kept coming and the person had to say out loud the third number back from the number they just heard. For example, say you listen to a stream of numbers: 8..5..3..7..9..1, etc. (‘8’ is the first number you’ve heard). When you hear ‘7’ then you’re asked to recall what the third one back was (8). When you next hear ‘9’, then you have to recall ‘5’, and so on. You can imagine the intense concentration that you need and how you’ll get fatigued trying to keep up with the number stream.
But every so often, the stream of numbers was paused and the subjects were given a decision to make. They were asked whether they would want to receive a certain amount of money right away or to wait for a bit and then receive a higher amount of money. In other words, they had to decide: should they take a reward now, or delay it and get more money? The choice seems obvious: of course anyone would want to wait and get a higher reward. But waiting for that reward does involve a bit of stamina, some mental effort.
The poor subjects became mentally worn down from that 3-back task. But what happened was that as the day wore on, they began to change their decisions, and chose the immediate rewards, even though they were of lesser value. It’s like being given a choice of getting a piece of delicious chocolate now or waiting to get two pieces of chocolate. If you’re really tired, you might just prefer to grab that tempting chocolate in front of you. The experiment lasted six hours and the subjects had less and less cognitive resources to use to make judgments. It was simply easier to decide to just take that monetary reward right away.
The researchers also had another group of subjects do easy tasks. When subjects did the easy tasks (which didn’t drain much of their cognitive resources), the subjects decided to wait for the higher monetary reward. Brain imaging done at different points of the task showed that the increase in impulsivity (taking that immediate reward) was tied to lower activity in a region of the brain associated with working memory and task-switching. This experiment showed that when we’re fatigued we tend to make more impulsive decisions.
When we’re tired, our decisions also become more inconsistent. In another study, researchers induced cognitive fatigue, using the same “n-back” task described above. When subjects were fatigued, they made more inconsistent decisions. In other words, if you were to be asked to choose a paint color for a room at the end of days when you’re exhausted after making many decisions, on one day you might choose a latte brown but on another day you might choose white.
Your decisions change after you take a break (with a meal)
Believe it or not, some research showed that decisions are affected not only if we’re tired, but they also might be affected if we’re hungry. A well-cited study of judicial decisions shows how they changed after taking a break with a meal. Over 1,000 parole decisions of Israeli judges were recorded over a 10-month period. Time of day, when a judge ate, and whether the decision was positive or negative were documented. It turns out that right before a food break, the positive parole decisions of Israeli judges were 0%, a ruling which was the status quo. But after a break for a nice breakfast or lunch, the decisions jumped to a whopping 65% positive—a change from the status quo. The researchers explained the change due to the judges’ mental resources being replenished, though they cannot say for sure whether it was due to the break or to eating. Interestingly, with more mental resources available, the judges’ decisions departed from the status quo.
So what is the take away from this result? If you have a really tough decision to make, you might be more likely to think more carefully about it after a break with a meal. On a recent day, I realized that amidst my decision-making in the renovation, I was famished. It was around 2 pm and I didn’t have much of a breakfast. So I took a break, had a nice lunch, and then found making decisions to be much, much easier.
If you’re applying for a job, try to schedule your main interview after lunch. You might have a better chance for a favorable decision after the manager had a nice break and a full stomach. If you’re pitching a business plan for your startup to a venture capital firm, schedule it after lunch. The same is true if you’re pitching a script to a producer. With less fatigue it seems more positive decisions might be made.
How to make decisions and be less exhausted
Try to make the hardest decisions when your attention is at its peak. For some people it might be at the beginning of the day; for others, they might need some time to warm up before they get into full gear. My own attentional peak is around mid-morning—that’s when I’m at my best. If you’re an early type, then your attentional peak will be quite early; if you’re a late type, then of course it’s much later.
When you can’t make a decision among different alternatives, then chances are none of the alternatives are good. Instead of thrashing around between the choices, try to generate new alternatives. Sometimes if you wait and take a break, you might see a clear winner with fresh eyes.
Above all, don’t make decisions when you’re mentally fatigued. If at all possible, defer hard decisions to the next morning. You’ll have a full tank of cognitive resources and better able to evaluate the possibilities. Make sure to take sufficient breaks. It’s surprising how clear cut decisions might seem with a refreshed mind.
You can read more about how we can reduce fatigue in our lives in my book Attention Span.