New research published in journal neuroimage suggest that spending more time on social media is associated with physical differences in brain development in young adolescents. Specifically, children who spent more time on digital platforms had thinner outer layers of their brains in areas responsible for attention, memory, and emotional regulation. These findings provide evidence that daily digital habits may be related to how the brain physically matures during a highly sensitive period of development.
Early adolescence is a period characterized by major physical, social, and psychological changes. During this period, the brain undergoes advanced restructuring to prepare the child for adulthood.
At the same time, more children are accessing smartphones and creating social media accounts for the first time. Recent statistics show that the majority of adolescents between the ages of 11 and 12 regularly use these platforms.
Scientists wanted to know if this widespread social media use was related to brain development. Previous studies have linked common screen time, such as watching TV or playing video games, to disrupted sleep, poor mental health, and physical changes in the brain.
Social media has a unique interactive element that sets it apart from passively watching a movie or playing a single-player game. Because social media use involves different thought processes, scientists wondered whether social media use might be associated with different patterns of brain development.
Previous research on this topic has often focused on older teens or lumped all viewing time into one broad category. By isolating social media use, the researchers hoped to paint a clearer picture of how platforms designed for social interaction affect growing minds.
“I first became interested in social media research through caring for young people with eating disorders, many of whom described spending hours on social media viewing content focused on unrealistic body ideals and weight. “Brain development is an important area that is still poorly understood, which motivated us to research this area,” said study author Jason Nagata, associate professor of pediatrics at the University of California, San Francisco.
For the study, researchers analyzed data from a large national project called the Adolescent Brain Cognitive Development Study. They focused on a specific group of 7,614 children between the ages of 10 and 13.
Scientists used a technique called structural magnetic resonance imaging to take detailed pictures of each child’s brain. This type of brain scan allows researchers to measure physical characteristics of the brain, such as the thickness, volume, and surface area of the cerebral cortex.
The cerebral cortex is the wrinkled outer layer of the brain that handles complex functions such as reasoning, language, and sensory processing. The researchers examined these brain measurements and compared them to participants’ self-reported social media habits.
Children completed a survey detailing how much time they spent on social media on a typical weekday and weekend. On average, adolescents used social media for just over 30 minutes per day, although some spent significantly more time online.
Participants also completed a six-item questionnaire designed to measure addictive behaviors related to social media. The survey asked people about their habits, such as trying to cut back on app usage but having trouble or feeling like they can’t stop scrolling.
To ensure the findings were as accurate as possible, the scientists considered a wide range of external factors. They adjusted the mathematical model for participants’ age, gender, race, genetic background, household income, and caregivers’ education level.
We also took into account the time children spent on other types of screens to ensure the final results specifically reflected their social media use. In addition to looking at predefined areas of the brain, the researchers used sophisticated computer algorithms to analyze the brain scans at incredibly high resolution.
This highly detailed analysis allowed us to examine the brain without relying on artificial boundaries between different brain regions. Researchers found that higher average daily social media use was significantly associated with a thinner cerebral cortex.
Specifically, children who spent more time on social media tended to have thinner outer layers in several broad areas of their brains. These areas include areas within the frontal, temporal, occipital, and parietal lobes.
These specific brain regions overlap with networks that control executive functions such as planning, memory, and impulse control. They also overlap with networks responsible for visual processing and maintenance of attention.
Additionally, scientists found that the entire right brain cortex volume was lower among people who used social media frequently. They found no strong association between social media use and brain surface area.
When scientists examined addiction questionnaires, they found no significant physical differences in the brain associated with social media addiction. Physical changes were tied strictly to time spent on the platform, rather than addictive behavioral patterns.
In the developing adolescent brain, the gradual thinning of the cerebral cortex is actually part of normal growth. This natural process is known as synaptic pruning, and the brain eliminates unused connections to increase efficiency.
However, excessive or accelerated hair thinning can be a marker of abnormal growth. Previous studies have linked excessive and rapid thinning of the cortex to difficulties with emotion regulation and increased risk of mental illness.
“Increased social media use is associated with differences in brain structure,” Nagata pointed out to PsyPost. “Social media use in adolescents was associated with reduced cortical thickness across the prefrontal, temporal, occipital, and parietal lobes. The identified regions were at key nodes in the default mode network, prefrontal executive control network, visual processing, and attention networks. However, we cannot conclude whether these differences are a consequence of social media use or a predisposing factor.”
Children who are born with thinner cerebral cortexes may simply be more drawn to social media use. The researchers also noted that the physical differences observed, while mathematically significant, were relatively small in size. The magnitude of these brain differences was comparable to the effects seen from watching television or reading books.
“Reduced cortical thickness is not necessarily a bad thing,” Professor Nagata points out. “During development, our brains shrink and become more neurally efficient as unnecessary neural connections are naturally removed. These findings should not be interpreted solely as good or bad.”
“Furthermore, given the cross-sectional design of this paper, we cannot determine whether these changes are a result of or induce social media use. Correlation does not imply causation. Further research is needed to understand the direction of these associations and determine whether there are long-term behavioral effects.”
The scientists also did not measure the type of content children were consuming. Scrolling through educational videos can engage your brain in a different way than experiencing cyberbullying or viewing highly curated lifestyle images.
Researchers now plan to follow these participants over several years to see how their brains change over time. This longitudinal approach will help reveal whether social media use accelerates brain changes, or whether pre-existing brain differences drive social media habits.
Scientists also hope to use functional brain scans in the future to observe how young people’s brains behave while using social media. Because many of the children who participated in the study were under the age of 13, the researchers suggest their findings highlight the need for stronger online age verification policies.
The study, “Social Media Use and Early Adolescent Brain Structure: Findings from the Adolescent Brain Cognitive Development (ABCD) Study,” was authored by Jason M. Nagata, Kevin Bao, Stuart B. Murray, Pierre Nedelec, Racquel A. Richardson, Sahana Nayak, Elizabeth J. Li, Jennifer H. Wong, Eva M. Muller-Oehring, and Aaron. Scheffler, Fiona C. Baker, Andreas M. Rauschecker, and Leo P. Sugrue.
