Single mothers, untenured professors, young reporters and on-call doctors might have a thin silver lining for their hurried days and response for the people who insist on slowing down: All that hustling may translate into superior brain power as you get older, as a study finds that the busiest people perform best on cognitive tests.

Sara Festini, a postdoctoral researcher at the University of Texas, Dallas, and her adviser, Denise Park, published the study in Frontiers in Aging Neuroscience on Tuesday. They tested over 300 people between the ages of 50 and 89 on cognitive functions including memory, reasoning and mental quickness.

These same people also answered questionnaires on their busyness. "These are self-report data," Park says. "People who tend to report chronic busyness tend to report it as a stress. Like 'Oh God, I'm just so busy.' If you're chronically busy and dumping stress hormones into your body, that could be bad for your cognition."

Festini and Park at first imagined that the harried, mentally taxed among us could be wearing our minds away. "[They'd] end up with worse cognition," Festini says. But on every test, those who had fuller days and less time on their hands outperformed those who were less busy. "We were somewhat surprised, I have to be honest," Park says.

Instead, the busier the individual, the higher he seemed to score. It's possible, the researchers hypothesized, that the daily workout of completing task after task is building our brains up and improving mental skills. That performance gap between the busy and the free seemed to be wider among older participants too, "which is particularly exciting," Park says.

If those with crammed schedules have sharper minds, then staying active in old age could protect against dementia. Past research has shown that this might be the case, and that includes not just mental effort but physical exertion. Park has done research in the past suggesting that engaging in new, mentally difficult tasks does seem to improve certain cognitive functions.

Still, Festini and Park are hesitant to say busyness equals staying mentally sharp. "It could be that people become slowly less busy over their lifetime as dementia [sets in]," Park says. That would make less busyness a consequence of failing cognition, not the other way around.

Or it could be that those who are "better endowed cognitively are more likely to take on more roles and tasks," Margie Lachman, a cognitive psychologist at Brandeis University who was not involved in the work, writes in an email to Shots. But she also thinks the study has a promising and rather sanguine hypothesis. "Ironically, I am too busy," she joked in one email. "At least my cognition [may] benefit."

But Park doesn't want to paint a rosy picture of the chronically busy or stressed. It's possible the busiest among us will still suffer. "Maybe those people are experiencing some negative effects from a lifetime of busyness. We haven't looked at that," she says.

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