We're all guilty of letting our minds wander when we're supposed to be doing something else. A little distraction is likely inevitable. But a study led by Matt Welhaf, a postdoctoral researcher in psychological and brain sciences in Arts & Sciences at Washington University in St. Louis, reveals a surprising trend: Our minds wander less as we age and, when older adults do let their minds drift, they're more likely to be distracted by pleasant thoughts rather than worries.

Co-authors of the study, published in The Journals of Gerontology, Series B, include Julie Bugg, a professor of psychological and brain sciences in Arts & Sciences, and Jonathan Banks, an associate professor of psychology and neuroscience at Nova Southeastern University in Fort Lauderdale, Florida.

Researchers recruited 175 younger adults aged 18 to 35 and 175 adults over 60 to participate in the study. Subjects were asked to perform a simple online task, such as hitting a spacebar every time the name of an animal appeared on the screen. During the task, subjects periodically saw a prompt asking if they were thinking about the task, their performance, or something off-task. If their mind had strayed, they were asked if they were thinking about something negative, positive or neutral.

Compared with older adults, younger adults were more likely to be thinking about something other than the task, a finding that echoes previous studies. But this was the first study to take a closer look at the emotional content of wandering thoughts. Compared to older adults, younger adults reported more passing thoughts that they perceived as negative. "They might have been thinking, 'Wow this is so boring, and I have other things to do today' or 'I have bills I need to pay,'" Welhaf suggested.

Older adults, in contrast, were less likely to be distracted by negative thoughts. "They were more able to focus on what they are supposed to be doing," Welhaf said. But when their minds did wander, the thoughts spanned the emotional spectrum. "There wasn't a dominant emotional direction to their thoughts, yet, interestingly, older adults were just as likely as younger adults to report positive passing thoughts."

This study offers the first evidence that older adults might be able to tune out negative thoughts when performing a task. "As we age, what we become concerned about changes," Welhaf said.

There were signs that the wandering minds of younger adults may have hurt their performance in the experiment. Compared with older adults, the younger participants responded more quickly to the prompts—but they also made more errors. "Older adults actually performed better overall," Welhaf said. That's likely because they were more motivated and focused. "They were happy to be contributing," he said.

The team hopes to build on these findings with additional research. Welhaf said they would like to conduct in-person tests that might be able to capture nuances about the causes, contents and consequences of wandering thoughts that don't show up in online experiments. In theory, he said, a deeper understanding of the direction of wandering minds could lead to new ways to help younger adults direct their focus away from negative thoughts and back to their current tasks or goals.