The Secret Power of Our Daydreams

Staring into space may get a bad rap, but a study published in Proceedings of the National Academy of Sciences earlier this year found that cognitive capacity actually got a bit of a boost when scientists used electrodes to stimulate the part of the brain that caused the subjects’ minds to wander.

“We showed that an increase of mind wandering as a result of our stimulation did not come in place of the performance of an external task,” said lead researcher Vadim Axelrod, a postdoctoral fellow at Bar-Ilan University’s Cognitive Neuroscience Lab in Israel. “In other words, we to some extent enhanced the general cognitive capacity.” The findings are surprising because mind wandering has previously been shown to decrease when task performance increases.

The Bar-Ilan study is hardly the first to show that, despite some negative effects, letting your mind wander can have benefits too—in particular the ability to access an insight or experience an “aha” moment. It’s this advantage of mind wandering that explains why our best ideas so often come in the shower (or, in Archimedes’ case, the bathtub), and how being engrossed in a mindless task can culminate in a shout of “Eureka!”

How often do we daydream anyway? Let’s put it this way: If you find yourself trying to finish a report at work but spend about half the time thinking about what to eat for lunch instead, you’re in good company: A 2010 study by two Harvard psychologists found that we humans let our minds wander for 46.9 percent of our waking hours.

That study was one of several that examined the downside of daydreaming. It’s probably no surprise that thinking about other things tends to have a negative effect on performance indicators like sustained attention, reading comprehension, and working memory. The Harvard study found that focusing on something other than what you’re doing at the moment can also bring down your mood. “A human mind is a wandering mind, and a wandering mind is an unhappy mind,” researchers Matthew Killingsworth and Daniel Gilbert wrote in the journal Science.

But wait! Before you whip out your mindfulness meditation manual to help you live in the moment, you should be, well, mindful of all the good things your itinerant brain can bring back from its travels.

Research has shown that the potential advantages of mind wandering include improvements in creative problem solving—the kind that leads to the lightbulb going off over your head—as well as the ability to plan for the future. Basically, we humans can be “inspired by distraction”—the title of a 2012 study in the journal Psychological Science that demonstrates how not being in the moment can provide just the inspiration you need.

The study, led by Benjamin Baird of the University of California, Santa Barbara, gave 145 undergraduates two tasks in which they had two minutes to list as many uses as they could think of for commonplace objects like bricks. The subjects either continued without a break—the equivalent of forcing yourself to keep your butt in the chair—or took a 12-minute break in which they were assigned to rest, perform a demanding memory task, or engage in an undemanding activity. Then they were given new creative tasks as well as a second chance at the original assignments.

The group that took part in an undemanding task that did not require all their attention, the kind of activity that in the real world would be something like taking a shower or washing dishes, did about 40 percent better than the other three groups at the repeated creative tasks (but not the new ones), demonstrating “significantly greater improvement” than any of the other groups.

Too bad the findings came out quite a few years after my parents used to make me sit for hours at the dining room table on Sundays while I stared at my weekly fourth-grade essay assignments, facing a window through which I could watch my sisters play in the backyard. I’d have been better off looking at the assignment, going out out to play while my brain cooked up some essay ideas, and coming back in later to write it all down.

Sometimes the insight we need looks less like a lightbulb turning on all at once and more like a gradual increase in lighting intensity, a day-to-day hashing out of what needs to be done. That’s what happens when we use our time in traffic or at the doctor’s office to think ahead, something the wandering mind is particularly good at. Anticipating and planning future events is “an important function of mind wandering,” especially when people are first primed to consider their personal goals, according to a 2011 study led by Belgian researcher David Stawarczyk.

All that planning could have to do with the positive correlation that has been found between having a good working memory and letting one’s thoughts drift a lot. “Our results suggest that the sorts of planning that people do quite often in daily life—when they're on the bus, when they're cycling to work, when they're in the shower—are probably supported by working memory,” said Jonathan Smallwood of the Max Planck Institute for Human Cognitive and Brain Science in Germany, one of the researchers involved in the study of working memory, which appeared in Psychological Science in 2012. “Their brains are trying to allocate resources to the most pressing problems.”

In short, whatever the drawbacks of daydreaming, it can also be just the thing you need to figure out what your week is going to look like, solve a problem that’s been troubling you, or let your next great idea click into place. (And, as you’ve probably figured out for yourself, letting our minds wander can also keep them from being numbed by boredom, allowing us to overcome tedium by escaping into our thoughts.)

Perhaps the authors of the “Inspired Distraction” study said it best. “From a theoretical perspective, this research also helps to establish at least one benefit from engaging in this otherwise seemingly dysfunctional mental state,” they wrote. “Although mind wandering may be linked to compromised performance on an external task and may be a signature of unhappiness, it may also serve as a foundation for creative inspiration.”