Everyone thinks they’re great at multitasking, even though research has found that only 2 percent of the population can actually be considered “supertaskers.” Multitasking often hinders our work performance, as much as we hope it doesn’t. But surely there’s no harm in multitasking if we’re only watching TV and texting, right?

As it turns out, “media multitasking,” or using multiple forms of media simultaneously, is associated with poor cognition. This finding comes from a new study, published in Psychonomic Bulletin & Review, which focused on children’s media usage. Though media multitasking is especially common among adolescents, its influence on their school performance has never been analyzed before, the researchers said.

For the study, researchers administered a questionnaire to 73 eighth grade students that asked them how many hours per week they spent on certain activities, as well as how often they combined these activities. Activities included watching television or videos, listening to music, playing video games, reading print or electronic media, talking on the phone, instant messaging or texting, creating crafts, and writing.

The students’ cognitive capabilities (working memory, manual dexterity, and vocabulary) and personality traits (grit, conscientiousness, and impulsiveness) were also tested. To measure the students’ academic abilities, the researchers collected their scores on state math and English exams. The researchers also asked the students whether they believed their academic abilities were fixed or could be improved.

Based on all of the data collected, the researchers discovered that students who spent more time media multitasking were the most likely to underperform in school. Not only did these students score more poorly on state exams, they also scored lower on cognitive exercises for working memory, were more likely to be impulsive, and believed more often that their intelligence was fixed.

"We found a link between greater media multitasking and worse academic outcomes in adolescents,” said Amy Finn, one of the study’s leaders, in a press release. “This relationship may be due to decreased executive functions and increased impulsiveness — both previously associated with both greater media multitasking and worse academic outcomes.”

Though the researchers noted that these findings support previous media multitasking studies conducted on adults, it is still not possible to establish a causal link between media multitasking and poor cognitive abilities.

“The direction of causality is difficult to establish,” Finn said. “For example, media multitasking may be a consequence of underlying cognitive differences and not vice versa.”

With that being said, the evidence suggests that not much good can come from media multitasking. In addition to the academic consequences, research has found a link between media multitasking, depression, and anxiety. And in another study, researchers discovered multitasking on multiple media devices can actually cause structural changes to occur in your brain, decreasing the amount of gray matter — composed mainly of neural cell bodies.

If multitasking can indeed influence our brain’s structure, then children may be especially prone to these changes since their brains are still in development. Children also spend an enormous amount of time with media these days, making them an especially important group to include in further research. In the current study, students watched 12 hours of television per week on average, and media-multitasked at least 25 percent of the time.

Source: Calin MS, Leonard JA, J. DE, Finn AS. Media multitasking in adolescence. Psychonomic Bulletin & Review. 2016.