The science of why you have great ideas in the shower

If you’ve ever emerged from the shower or returned from walking your dog with a clever idea or a solution to a problem you’d been struggling with, it may not be a fluke.

Rather than constantly grinding away at a problem or desperately seeking a flash of inspiration, research from the last 15 years suggests that people may be more likely to have creative breakthroughs or epiphanies when they’re doing a habitual task that doesn’t require much thought—an activity in which you’re basically on autopilot. This lets your mind wander or engage in spontaneous cognition or “stream of consciousness” thinking, which experts believe helps retrieve unusual memories and generate new ideas.

“People always get surprised when they realize they get interesting, novel ideas at unexpected times because our cultural narrative tells us we should do it through hard work,” says Kalina Christoff, a cognitive neuroscientist at the University of British Columbia in Vancouver. “It’s a pretty universal human experience.”

Now we’re beginning to understand why these clever thoughts occur during more passive activities and what’s happening in the brain, says Christoff. The key, according to the latest research, is a pattern of brain activity—within what’s called the default mode network—that occurs while an individual is resting or performing habitual tasks that don’t require much attention.

Researchers have shown that the default mode network (DMN)—which connects more than a dozen regions of the brain—becomes more active during mind-wandering or passive tasks than when you’re doing something that demands focus. Simply put, the DMN is “the state the brain returns to when you’re not actively engaged,” explains Roger Beaty, a cognitive neuroscientist and director of the Cognitive Neuroscience of Creativity Lab at Penn State University. By contrast, when you’re mired in a demanding task, the brain’s executive control systems keep your thinking focused, analytical, and logical.

A cautionary note: While the default mode network plays a key role in the creative process, “it’s not the only important network,” Beaty says. “Other networks come into play as far as modifying, rejecting, or implementing ideas.” So it’s unwise to place blind faith in ideas that are generated in the shower or during any other bout of mind wandering.

What is the default mode network

Marcus Raichle, a neurologist at the Washington University School of Medicine in St. Louis, and his colleagues serendipitously discovered the default mode network in 2001 when they were using positron emission tomography (PET) to see how the brains of volunteers were functioning as they performed novel, attention-demanding tasks. The team then compared those images to ones made while the brain was in a resting state and noticed that specific brain regions were more active during passive tasks than engaging ones.

However, because the function of each brain region isn’t well characterized and because a specific brain area can do different things under different circumstances, neuroscientists prefer to talk about “networks of brain areas,” such as the default mode network, which function together during certain activities, according to John Kounios, a cognitive neuroscientist and director of the Creativity Research Lab at Drexel University in Philadelphia.

Raichle named this network the “default” mode network because of its heightened activity during idle periods, says Randy L. Buckner, a neuroscientist at Harvard University. But it’s something of a misnomer because the default mode network is also active in other mental tasks, such as remembering past events or engaging in self-reflective thought.

The network is also “involved in the early stages of idea generation, drawing from past experiences and knowledge about the world,” explains Beaty. “When you’re not actively working on a problem, the brain keeps spinning and you can get restructuring of elements of the problem, pieces get reshuffled, and something clicks.” The DMN, he adds, “helps you combine information in different ways and simulate possibilities.”

Researchers have discovered that when it comes to measures of creativity, there's a positive correlation between creative performance and gray matter volume of the default mode network. In other words, as far as creativity goes, size matters when it comes to the DMN.

To investigate changes in brain activation and connectivity between different regions of the DMN, researchers asked volunteers to alternate between activities involving high cognitive effort (naming colors), low cognitive effort (reading words), and no cognitive effort (resting). They found that the default mode network was most active when the participants were at rest and more active during the low effort task than the high effort one, according to the study in the April 2022 issue of Scientific Reports. This suggests that DMN activity can toggle up and down, as if on a dimmer, perhaps stopping at intermediate points along the way, depending on the level of cognitive challenge that’s required.

The link to creative thinking was demonstrated in a study published in January that involved patients who were awake during brain surgery so surgeons could map the exposed cortical surface for language functions. As direct electrical stimulation was applied to their default mode network or another area of their brain, the patients were asked to perform an "alternate-uses task" that involved inventing unusual uses for an everyday object—in this case, a paper clip—which is a way of evaluating divergent thinking abilities. The researchers found that the patients’ ability to successfully perform the alternate-uses task depended on the strength of connections between nodes of the default mode network.

“The default mode network seems to be an important source of creativity, and it’s decidedly associated with mind-wandering,” says Jonathan Schooler, a psychological scientist at the University of California, Santa Barbara. Indeed, a study in the February 2022 issue of Human Brain Mapping found that positive, constructive daydreaming—“characterized by planning, pleasant thoughts, vivid and wishful imagery, and curiosity”—is associated with activity in the default mode network and creativity.

The benefits of mind-wandering 

Whether we realize it or not, we all engage in mind-wandering on a regular basis, says Beaty, noting that there are different kinds. There’s deliberate mind-wandering, where you try to exercise some level of control or direction to your thinking; and spontaneous mind-wandering, which happens in the brain without us directing it. In a study in a 2020 issue of PNAS, researchers using electroencephalograms to track people’s brain activity found that spontaneous mind-wandering occurred 47 percent of the time.

It’s the spontaneous form, in particular, that allows you to combine information and ideas in new ways. “When your mind drifts away from a situation into an internal reverie, that’s where you can have creative insights,” Schooler says. “In this pleasurable state, you’re allowing thoughts to playfully cross your mind.” Keep in mind, he adds, “sometimes you have to do the work to create a problem space—that sets the groundwork for spontaneous ideas to emerge.”

This is often referred to as "the incubation effect," which occurs when you spend time away from a particular problem or challenge and your mind has the chance to wander and generate novel ideas through unconscious associative processes.

To discover when people get their most innovative ideas, Schooler and his colleagues asked professional writers and physicists to keep a diary for two weeks, in which they reported their most creative idea of the day, what they were doing when it occurred, and whether it felt like an “aha” moment. Approximately 20 percent of their most significant ideas occurred while they were engaging in an activity other than working or while they were thinking about something unrelated to the creative idea, according to the study published in a 2019 issue of the journal Psychological Science. More significantly, ideas sparked during mind-wandering moments were more likely to be associated with overcoming an impasse on a vexing problem and to be viewed as “aha” moments.

“You need that exploratory aspect of idea generation in order to be creative,” says Rex Jung, a neuropsychologist at the University of New Mexico in Albuquerque. But, he adds, you need other parts of your brain to pick an idea, evaluate its viability, and implement it in the real world. He notes, “It’s an interplay or dance between the default mode network and the cognitive control network that allows you to generate a creative idea then implement it effectively.”

How to spark creativity

Besides leading to greater self-understanding, gaining insights into these aspects of the creative process can help you maximize your brain power in various situations. But keep in mind, Jung points out, “these are early days, and there’s still a lot to learn about how the brain creates.”

As a first step, it’s wise to prioritize getting plenty of good quality sleep, which can improve your mood and help with memory, says Kounios who is co-author of The Eureka Factor: Aha Moments, Creative Insight, and the Brain. While you’re asleep, he notes, “the information you take in during the day is transformed from a fragile state into a more durable state which can bring aha moments.”

Immediately upon awakening from a full night’s sleep or even a 20-minute nap, Christoff recommends paying attention to thoughts and ideas that occur to you in that liminal state between being sound asleep and fully awake—that’s a time when your ideas are “often quite free-flowing,” she adds, which means you can tap your creative potential.

To consciously activate your DMN and creative ideas during the day, allow yourself to spend time doing activities that aren’t cognitively demanding—such as going for a walk, taking a warm bath, or gardening—without listening to music or a podcast. Simply let your mind wander. Do this when you’re “in a state of psychological safety, where there’s no danger to having an unusual thought and no immediate task to perform,” Kounios says. (In other words, don’t do this while driving.)

During the day, doing something easy and familiar, often involving some kind of movement, is likely to facilitate the flow of spontaneous thoughts. When you’re in the shower, for example, “you don’t have a lot to do, you can’t see much, and there’s white noise,” notes Kounios. “Your brain thinks in a more chaotic fashion. Your executive processes diminish and associative processes amp up. Ideas bounce around, and different thoughts can collide and connect.”

There’s some research that suggests spending time in nature—which can evoke a sense of awe, as well as inducing relaxation—is conducive to mind-wandering because it allows “your attention to expand to fill the space,” Kounios says. “Taking a walk in nature can improve your mood and expand your thoughts to include remote ideas and associations.”

That’s why if you’re trying to come up with a new idea or solve a problem, it’s a good idea to work hard on it then take a break and go for a walk if you reach an impasse. “This allows your mind to subconsciously work on something you were consciously working on,” Christoff says.

A key factor: The activity needs to last long enough “to present the opportunity to get into a different mode of thinking that we usually guilt ourselves out of,” Christoff explains. “We need to become relaxed enough mentally in order to not try to be productive or reach some goal. With habitual activities we engage in with some regularity, we don’t feel guilty about letting our minds wander—that’s when the mind can reach new places.”

So don’t be afraid to unplug and carve out time for mind-wandering and musing on a regular basis. “One of the costs of this multimedia world we live in is we don’t leave enough time for personal reverie,” Schooler says. Giving your mind a chance to roam is an investment in your creativity, and that’s time well spent.