How often do good ideas strike you while you shower? It happens to me all the time. The more complex a problem, the tougher a decision I need to make, the more likely the solution will “hit me” while showering—or while I’m doing something else that doesn’t require my full attention. The solution seems to come out of the blue.
Of course, the solution did not really come out of the blue. Thoughts don’t materialize out of nowhere: they’re a result of some process in the brain. But is the solution a result of a conscious brain process or the result of an unconscious one?
Intuitively, the process appears to be unconscious. Ap Dijksterhuis, a psychologist who researches unconscious thought, points out that many famous thinkers and artists have noted how inspiration or the solution to a complex problem suddenly struck them. My favorite example from one of Dijksterhuis’s recent papers is that of the mathematician Henri Poincaré:
[He] only worked on math 4 hr a day (from 10:00 a.m. to 12:00 p.m., and from 5:00 p.m. to 7:00 p.m.), convinced that for the rest of the time his unconscious was thinking and that, at some point, his unconscious would present a solution to the problem he was studying.
If it’s true that the brain unconsciously works on problems and creates ideas, we could change how we work to allow plenty of time for the unconscious to do its thing—we could work like Henri Poincaré. And psychologists have tried to determine, experimentally, whether unconscious thinking helps solve problems. Sadly, the experimental evidence disappoints.
Dijksterhuis and some of his colleagues popularized Unconscious Thought Theory in a 2006 paper. This theory postulates that the brain is better at solving complex problems unconsciously than consciously, possibly because the brain can process more information per second when working unconsciously than when working consciously. Dijksterhuis and others ran experiments to test the theory, with setups such as the following:
Researchers present students with a few hypothetical apartments (let’s say four) that each have a large number of characteristics (let’s say a dozen). The researchers first allow the students to review each apartment’s characteristics (so 48 features in all). Then students in the control group get a few minutes to consciously think about the apartments. Students in the treatment group, by contrast, must solve a puzzle during that time, to distract the brain from the apartment choice problem. Afterwards, researchers ask the students to identify the “best” apartment.
If unconscious thought is better at making complex decisions, researchers hypothesized, we would expect the students who were not consciously thinking about the apartment choice—because their attention was focused on solving a puzzle—to pick the “best” apartment more often. (Normally the hypothetical apartments, or the other objects to be compared, are created so that one has substantially more positive attributes than the others, so that given enough time to compare, it is reasonably clear which choice is “the best”.)
At first, in such experiments, students who had been distracted with a puzzle to solve seemed to make better choices. That is, a higher percentage of them identified the “best” choice. But other studies found no such effect. And alas, a 2015 meta-analysis of all prior studies that ran such experiments finds no convincing evidence that unconscious thought is better at solving the problems put before participants in the experiments:
[T]here exists no reliable support for the claim that a momentary diversion of thought leads to better decision making than a period of deliberation.
Yet the intuition that unconscious thought helps us solve problems is strong. Maybe a “momentary diversion of thought” is not enough for the unconscious brain to get going. Or maybe we consciously think about problems without realizing it, so that the conscious brain is responsible after all.
But wait—is it even possible to think consciously about something without paying attention to it? Dijksterhuis writes:
Whether people can be conscious of something without paying attention to it is the object of an interesting debate …
Either way, the fact that unconscious thinking does not result in better decisions in the case of momentary distractions does not deter Dijksterhuis and his colleagues from asking when unconscious thought does have a role, if ever. They cite neuroscientific research as a promising way of determining whether a person’s brain can work on certain problems while that person attends to something else—and if so, whether such unconscious thought leads to better decisions.
For now though, the scientific literature does not establish whether unconscious thought helps us make decisions or provides us creative insights. But the research is ongoing. And I, for one, would love to find out how unconscious thought helps my thinking—or, if it doesn’t, what else accounts for sudden inspiration or clarity in decision making.
Dijksterhuis concludes that “[i]n the forthcoming years, it will most likely become clear exactly which cognitive operations can be done unconsciously.”
I’ll stay tuned.