Decisions, Decisions – I Can’t Make Up My Mind. I’ll Just Have to Sleep On It.
What is the best way to make tough decisions? In the February 17, 2006 issue of Science magazine, Ap Dijksterhuis, a Dutch psychologist, published the startling claim that people make better decisions about complex choices if they don’t think too hard about them. He based this counterintuitive conclusion on several studies. In the first study, done in his laboratory, subjects read a brief description of four hypothetical cars and were given four minutes to mull things over before picking the best one. When the car description involved only four attributes – such as good mileage, poor legroom, etc. – the subjects easily chose the best car (the one with the most pluses). But when the complexity was increased to 12 attributes, and they were given the chance to think hard about it, they picked the best car no more often than chance. However, if on the other hand, they were distracted by solving anagram puzzles during the four minutes they were allotted to make up their minds, they picked the best car twice as often as chance. Not thinking about the choice produced better results. In a second, related study (taking his concept into the field), he found that Ikea shoppers were more satisfied with complex purchases if they didn’t deliberate too much about their choice.
Can it be that conscious thought is, in some cases, inferior to unconscious thought? Dijksterhuis suggests that conscious thought has low capacity; accordingly, the chooser tends to take into account only a subset of the relevant information. In contrast (he argues), unconscious thought can integrate large amounts of information and provide appropriate weighting to many attributes. How often have you tried to make a hard decision by making long lists of the positives and negatives? It may help, but in the end you are quite likely to say, “The heck with it, I’ll just go with my gut feeling.” And if you do base your decision on scoring lists, the ultimate decision may not feel satisfying, even if it seems rational. Dijksterhuis advises that, when confronting a difficult decision, it’s best to gather the relevant information, give it your full attention at first, but then allow your unconscious mind (your gut) a chance to digest it before you make up your mind. In other words, “sleep on it.”
The implication of this work is that the brain is somehow working on a problem “offline” (as the computer people would say) when we are not attending to it. In my experience, if I have forgotten someone’s name, I have better luck if I stop trying to remember it. Eventually it will “pop” into my mind, as if my brain were working on the problem in the background without my being aware of it.
Do such offline processes occur when we are asleep? Indeed, there is compelling evidence that certain kinds of mental processes, particularly memory consolidation, occur during sleep, even though we are unconscious. Some researchers have suggested that sleep may be especially important for “procedural memory” (such as learning to play the piano) in contrast to memorizing lists of facts called “declarative memory.” For example, in a recent study, subjects were trained in a finger-tapping test. Half were trained in the morning and re-tested in the afternoon, and half were trained in the evening and re-tested in the morning. Not only did the subjects who got a night’s sleep, between training and testing, perform better, but brain imaging also showed they had greater activation in the areas involved with memory function.
It has been suspected for a long time that dreaming (REM sleep) may be important for memory consolidation. Perhaps by recapitulating the experiences of the day in the typically bizarre, distorted manner characteristic of a dream, memories are somehow strengthened. In animals, specific REM sleep deprivation impairs procedural learning. On the other hand, at least one scientist has speculated that dreaming involves “dumping” irrelevant memories (like the iconic wastebasket on your computer screen). At this time, the role of REM sleep in memory consolidation remains controversial. It has been pointed out that certain antidepressant drugs (the MAO inhibitors) can essentially obliterate REM sleep, and yet memory function is seemingly unaffected.
So, when facing a tough choice, does it pay to “sleep on it?” I suspect that what is meant by that phrase is a process of allowing feelings and emotions to stabilize, avoiding a “rush to judgment.” An initial reaction of excitement (or disgust) can moderate with time. Also, it takes time to rehearse the potential outcomes of a decision.
Feelings are critical for decision-making. The really big decisions in life – who to marry, when (and if) to get pregnant, which house or car to buy – all rely on a combination of analysis and affect. We have a pretty good idea of how the analytic calculator works; we are less sure how the feeling calculator works. Mr. Spock was smarter than Captain Kirk, but all he could do was to outline the alternatives. Captain Kirk was the one to make the big decisions, usually based on a gut feeling. Often his decisions seemed ill advised at first, but they always worked out well in the end. I don’t know if he ever retired to his quarters on the starship Enterprise to “sleep on it” before making up his mind.
Robert Sack, M.D. is professor emeritus in the Department of Psychiatry at the Oregon Health and Science University. He is a specialist in sleep disorders.
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