I have two children, and they are a study in contrasts: My son works at a gym designing and building rock-climbing walls; In his spare time, he climbs them. My daughter is a Ph.D. student in immunology; In her spare time, she writes novels. My son is the sort of person you want around in a crisis, cool-headed and springing to action. Let’s just say my daughter is not. My son spends money as soon as he earns it. My daughter manages to sock money away into a retirement fund, even on a student income. My son shrugs off unexpected misfortunes, declaring that there’s “no point” in brooding over them. My daughter can worry herself to exhaustion over misfortunes that will never happen. Though both were classified as “gifted,” my son was bored and alienated at school, while my daughter flourished.
I’ve puzzled over their differences throughout their lives—how can two siblings contrast so completely along so many traits? It turns out that many of the personality divergences between my two children may boil down to the fact that, while my son’s mental life is closely connected to the outside world, my daughter spends much of her life inside her own head.
A 2010 study showed that people spent almost half their time thinking about something other than what they were doing. Generally, when your mind becomes detached from its immediate surroundings, the areas of the brain that process sensory information become less active, while activity ramps up in what’s known as the default mode network—interconnected brain regions that are active when people reflect on past memories or future plans, imagine the mental states of others, or think about “nothing in particular.”
The question is, is that good for you?
On the positive side, mind-wandering promotes planning for the future, allowing my daughter to lay the groundwork for financial security and a career with a long endgame. And it may be an essential ingredient in creativity. Several studies have shown that creativity blossoms under the same conditions that encourage mind-wandering—for example, an incubation period in which the mind is only lightly focused on an easy task is especially conducive to flashes of insight and imaginative solutions to problems.
On the negative side is the tendency to lose focus on the task at hand and make distracted mistakes—the thought of my daughter driving is never a comforting one. Less obvious, and even darker, is a possible connection to neuroticism, a personality style that comes with hair-trigger anxiety, obsessive negative thoughts that endlessly chase their own tails, and a heightened risk for depression.
One view has it that neuroticism is an amplified reaction to threat. This hypothesis receives support from evidence that showing neurotic subjects images of fearful faces triggers an exaggerated response in the amygdala, a brain region that has been linked to fearful emotion. But in a 2015 paper, Adam Perkins, a clinical psychologist at King’s College London, and his colleagues, argue that the engine of neuroticism is inward thought. As Perkins and his colleagues point out, neurotic people often feel anxious even when there’s no threat at all in the immediate environment. The anxiety is not attached to the here and now, in other words, but is a product of self-generated thought.
This theory is supported by a number of parallels between mind-wandering and neuroticism: Both are associated with creativity and with planning ahead for the future. Both are linked to activity in the default mode network of the brain. And there’s evidence that rumination itself may be a mood depressant. In a paper pessimistically titled “A wandering mind is an unhappy mind,” Harvard psychologists Matthew Killingsworth and Daniel Gilbert reported that people felt less happy when their minds strayed from the task at hand, even when they were dwelling on pleasant topics—and even when the task itself was not enjoyable.
The connection between inner thought and neuroticism feeds the myth of the suffering creative genius. As the Danish philosopher and lifelong depressive Søren Kierkegaard put it, a poet is “an unhappy man who in his heart harbors a deep anguish, but whose lips are so fashioned that the moans and cries which pass over them are transformed into ravishing music.”
But it would be wrong to conclude that all mind-wanderers must pay for their creative spark with a lifetime of fretful, brooding misery. A follow-up to the study by Killingsworth and Gilbert showed that mind-wandering was a mood-enhancer in at least one specific context: when the ruminators judged their own thoughts to be interesting. Another study found that thoughts related to the future and the self are followed by periods of markedly improved mood, even if the thoughts themselves were negative. This may explain why, although my son wallowed in gloomy boredom at school, my daughter thrived—she could always retreat to a rich world of inner thought more riveting than what was happening in the classroom.
One of my own friends, a successful poet, relentless ruminator, and one of the happiest people I’ve ever met, stands as an argument against Kierkegaard. He holds a day job as a lab technician doing routine, repetitive work that many would find dull, but that provides him with long incubation periods for his poetry, which he views as his real work. His example suggests that the path to happiness may not require turning down the rumination dial after all.
Julie Sedivy has taught linguistics and psychology at Brown University and the University of Calgary. She is the co-author of Sold on Language: How Advertisers Talk to You and What This Says About You and the author of Language in Mind: An Introduction to Psycholinguistics.