Teens’ brain changes linked to social media, study shows
The effect of social media use on children is a fraught area of research as parents and policymakers try to ascertain the results of a vast experiment already in full swing. Successive studies have added pieces to the puzzle, fleshing out the implications of a nearly constant stream of virtual interactions beginning in childhood.
A new study by neuroscientists at the University of North Carolina tries something new: conducting successive brain scans of middle-schoolers between the ages of 12 and 15, a period of especially rapid brain development.
The researchers found that children who habitually checked their social media feeds at around age 12 showed a distinct trajectory, with their sensitivity to social rewards from peers heightening over time. Teenagers with less engagement in social media followed the opposite path, with a declining interest in social rewards.
The study, published Tuesday in JAMA Pediatrics, is among the first attempts to capture changes to brain function correlated with social media use over a period of years.
The study has important limitations, the authors acknowledge. Because adolescence is a period of expanding social relationships, the brain differences could reflect a natural pivot toward peers, which could be driving more frequent social media use.
“We can’t make causal claims that social media is changing the brain,” said Eva Telzer, an associate professor of psychology and neuroscience at the University of North Carolina at Chapel Hill, and one of the authors of the study.
But, she added, “teens who are habitually checking
their social media are showing these pretty dramatic changes in the way their brains are responding, which could potentially have longterm consequences well into adulthood, sort of setting the stage for brain development over time.”
A team of researchers studied an ethnically diverse group of 169 students in the sixth and seventh grades from a middle school in rural North Carolina, splitting them into groups according to how often they reported checking Facebook, Instagram and Snapchat feeds.
At around age 12, the students already showed distinct patterns of behavior. Habitual users reported checking their feeds 15 or more times a day; moderate users checked between one and 14 times; nonhabitual users checked less than once a day.
The subjects received full brain scans three times, at approximately one-year intervals, as they played a computerized game that delivered rewards and punishment in the form of smiling or scowling peers.
The results showed that “teens who grow up checking social media more often are becoming hypersensitive to feedback from their
peers,” Telzer said.
The findings do not capture the magnitude of the brain changes, only their trajectory. And it is unclear, authors said, whether the changes are beneficial or harmful. Social sensitivity could be adaptive, showing that the teenagers are learning to connect with others, or it could lead to social anxiety and depression if social needs are not met.
Researchers in the field of social media warned against drawing sweeping conclusions based on the findings.
“They are showing that the way you use it at one point in your life does influence the way your brain develops, but we don’t know by how much, or whether it’s good or bad,” said Jeff Hancock, the founding director of the Stanford Social Media Lab, who was not involved in the study.
Over the last decade, social media has remapped the central experiences of adolescence, a period of rapid brain development.
Nearly all American teenagers engage with peers through social media, with 97% going online every day and 46% reporting that they are online “almost constantly,” according to the Pew Research Center.