Getting into the habit of checking social media "likes" and comments in middle school can significantly change the way students' "social brains" develop by the time they enter high school.

While children generally become more attuned to social interactions as they enter adolescence, those who are frequent, early social media users become particularly sensitive to anticipating social risks and rewards from their peers, finds a new longitudinal study published this week in the journal JAMA Pediatrics.

It's the latest study to connect newer media forms, like social networking sites or YouTube, to changes in adolescent development or behaviour.

Researchers from the University of North Carolina-Chapel Hill tracked how often a diverse group of 169 6th and 7th graders reported checking Facebook, Instagram, and Snapchat over a three-year period. Roughly every year, the students underwent functional magnetic resonance imaging, or fMRI - which maps brain activity - while playing virtual games featuring happy, angry, or blurred faces of other adolescents.

Over time, researchers found that "habitual" social media users - those who checked their social feeds 15 times a day or more - responded quicker and more intensely to perceived good or bad emotions from peers, compared to students who checked once a day or less. The areas of the brain associated with motivation and cognitive control became more active among the habitual students when expecting social rewards and punishments.

By contrast, students who used little social media reacted less strongly to social cues over the same time period.

"Social media provides a constant and unpredictable stream of social inputs to adolescents during a critical developmental period when the brain becomes especially sensitive to social rewards and punishments," wrote researchers led by Maria Maza of UNC-Chapel Hill's Developmental Social Neuroscience Lab.

For some students, they said, the greater long-term sensitivity associated with high social media use could lead to "checking behaviours on social media becoming compulsive and problematic," while for others, it could "reflect an adaptive behaviour that allows them to better navigate their increasingly digital environment."

Research piles up on media exposure

The current JAMA study comes on the heels of a similar longitudinal study published last month in the Journal of Adolescent Health, which found that 9- and 10-year-olds who spent hours a day playing video games or watching online algorithm-based videos (like YouTube) had a higher risk of developing obsessive-compulsive disorders.

"There's this ongoing dispute now about whether social media causes depression and suicidal ideation, or does it just exacerbate it in kids that already have it? Well, some kids are more prone, whether through genetic predisposition or behavioural predisposition, to the effects of certain types of media," said Dr Dimitri Christakis, the director of the Center for Child Health, Behavior, and Development at Seattle Children's Research Institute, who was not part of the study.

"I think the real question going forward is, how do we create a healthy online experience? No one would suggest, or at least most people wouldn't suggest, that we eliminate it entirely," he added.

The results of both studies may be particularly important as generations of students grow up enmeshed in social media platforms. In a nationally representative survey in 2022, nearly 80% of those ages 13-17 told the Pew Research Center that they check at least one of their social media feeds at least hourly, and more than a third said they did so "almost constantly."

The older the teenagers were, the stronger the social media attachment: 48% of students ages 13-14 and 58% of those 15 and up said it would be difficult for them to give up using social media.

 - TNS