The Value of Mind Wandering in Solving Difficult Problems

Some problems can be solved best by taking a break from trying to solve them.

Posted Feb 07, 2019

Source: mimagephotography/Shutterstock

I begin by listing four quite striking, possibly counterintuitive findings from research on problem solving.

1.  People who show the symptoms of ADHD—notably, a tendency to be easily distracted from the task at hand—have been repeatedly found to be much better at solving certain kinds of problems than are people who don’t show these symptoms.  I summarized and referenced some of the evidence for this in a previous essay (also see Boot, Nevicka, & Baas (2017).

2.  People who, because of strokes or tumors, have suffered damage to the prefrontal lobes of the cortex (brain areas that help focus attention and help develop conscious problem-solving strategies) have been found to be much better than people with intact brains at solving certain kinds of problems (Reverberi et al., 2005).

3.  Brain-intact people have been found to show great improvement at solving certain kinds of problems if a portion of their prefrontal lobes has been temporarily rendered less active by a process called transcranial direct current stimulation, which involves a slight electric current sent across the skull over a particular brain area (Luft et al, 2017).

4.  Dozens of experiments have shown that people who are stumped in solving certain kinds problem are subsequently much more likely to solve the problem if they take a break, in which they think about something else for awhile, than they are if they work continuously on the problem (for reviews, see Sio et al, 2017; Sio & Ormerod, 2009). This is called the “incubation effect.” A number of studies have shown that the incubation effect works best when, during incubation, the person is just daydreaming or working on some relatively easy set of tasks rather than focusing heavily on a new problem.  

What are these “certain kinds of problems”?  They are problems that cannot be solved through one’s routine, ingrained, well-trained ways of thinking.  They are sometimes called “insight problems,” because when you finally do solve them the solution seems to jump out from nowhere, and you experience the classic “aha” phenomenon.  Suddenly you see what you didn’t see before.  It seems magical.  From where did that solution come?

The solution must have come somehow from the unconscious mind. Our brain is an amazing machine that is always working on many things at once.  Our conscious experience of thought, which generally runs along a single track rather than many at once, reflects only a small portion of what the brain is doing.  On this, if on nothing else, Freud was right: The conscious mind is just the tip of the iceberg.  Apparently, when we stop thinking consciously about the problem that we have been unable to solve, the unconscious mind takes the problem on and continues to work on it in some way—not through the logical means of the conscious mind, but through some other kind of logic.  There are various theories about what the unconscious mind is doing.  One prominent theory is that it is checking out a broad range of potential links between elements of the problem and other information stored in memory, including links that are too remote for the conscious, logical mind to consider.  Suddenly, the mind hits a link that works, that solves the problem, and this awakens the conscious mind—“Aha, I see it now!”

On the basis of this theory, people with ADHD, or with damage to the  prefrontal lobe, or with a temporarily suppressed prefrontal lobe, are more likely to solve such problems than are other people because they are less able to maintain fixed attention.  They are more likely to allow their mind to wander and, therefore, more likely to allow the unconscious mechanisms to take over.

All the research I’ve referenced so far was done in laboratories, with insight problems created specifically for research purposes.  What about real-world problem solving?  In a very recent study, Shelly Gable, Elizabeth Hopper, and Jonathan Schooler, of the University of California, Santa Barbara. (2019), recruited 72 theoretical physicists and 113 professional writers (mostly screenwriters) as participants in a study of problem solving related to their professions.  Over a two-week period each participant was emailed a questionnaire each evening, which asked them to describe the most creative idea, if any, they had that day related to their work.  If they listed an idea, they were asked questions about what they were doing and thinking when they had the idea, and whether it entailed overcoming an impasse or felt like an “aha” moment, and how important and creative the idea was.

Of most interest for our purposes, the researchers found that approximately 20% of the creative ideas, for both physicists and writers, occurred at times when they were not thinking about the problem to which the idea pertained.  They occurred while they were away from their work and thinking about something else.  Moreover, these ideas were especially likely to be experienced as “aha” moments and to contain solutions to problems for which they had previously been at an impasse—that is, at a point where the problem had begun to seem unsolvable.  

Decades ago, long before I had ever heard of research like what I’ve described here, I discovered that the best thing for me to do when I am stuck on some problem—be it a problem of research design, or writing, or even a personal relationship problem—is to take a break.  For me, the best kind of break is to go outside for a walk or a bike ride, or to work in my garden or chop wood for my stove, and just let my mind go free as I do so.  Not always, but quite often I find that some insightful idea that solves or helps to solve the problem comes to mind as I’m traipsing through the woods or peddling down the road or mulching the tomatoes or splitting logs.  And even when no idea pops up, I haven’t wasted time.  My breaks produce good exercise, fun, tomatoes, and firewood.  

Sometimes when no solution comes during the break, one comes very quickly after I come back to the problem.  I figure in those cases that my unconscious mind had come pretty close to the solution and it just took a little further conscious attention to bring it forth.  Nowadays I go outdoors for at least an hour’s adventure of some sort nearly every day, whether or not I feel stuck on a problem.  Often new creative ideas come to mind that have nothing to do with problems I’ve been working on, but that suggest new projects that would be well worth working on.

Usually in my blog posts I urge you to let your children run free.  Now I’m urging you also to let your mind run free.


What have been your experiences with solving seemingly intractable problems?  Do you take a break?  What kind of break works best for you?  Please share in the comments section below.  This blog is in part a forum for discussion, and your stories, comments, questions, and disagreements are valued and treated with respect by me and other readers. As always, I prefer if you post your thoughts and questions here rather than send them to me by private email. By putting them here, you share with other readers, not just with me. I read all comments and try to respond to all serious questions if I feel I have something useful to say and can find the time to do so.


Boot, N., Nevicka, B., & Baas, M. (2017). Subclinical symptoms of attention-deficit/hyperactivity disorder (ADHD) are associated with specific creative processes. Personality and Individual Difference, 114, 73-81.

Gable, S. L., Hopper, E. A., & Schooler, J. W. (2019). When the muses strike: Creative ideas of physicists and writers routinely occur during mind wandering.  Psychological Science.  Published online, Jan. 17, 2019.

Luft, C. D. B., Zioga, I., Banissy, M. J., & Bhattacharya, J. (2017). Relaxing learning constraints through cathodal tDCS on the dorsolateral prefrontal corex.  Scientific Reports, 7, 2916.  

Reverberi, C., Toraldo, A., D’Agostini, S., & Skrap, M. (2005).  Better without (lateral) frontal cortex? Insight problems solved by frontal patients. Brain, 128, 2882-2890.

Sio, U. N., & Ormerod, T. C. (2009).  Does incubation enhance problem solving?  A meta-analytic review.  Psychological Bulletin, 135, 94-120.

Sio, U. N., Kotovsky, K., & Cagan, J. (2017). Interrupted: The role of distributed effort and incubation in preventing fixation and generating problem solutions. Memory and Cognition, 45, 553-565.  

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