Myth Versus Reality: Screen Use, Social Media May Not Harm Children’s Cognitive Development

Adolescents who used social media the least had the highest cognitive scores, while those who used it the most had the lowest. Increased social media use was associated with poorer performance in memory, language-related tasks, and lower overall cognitive composite score. The differences, though measurable, were not large

The children of today use tools that were not available 40 years ago, when learning occurred primarily by reading books, listening to lectures, participating in discussions, and engaging in conversations. Screen time during that era was limited to television featuring programmes mostly meant for adults and without any interactive features. Mainstream use of interactive touchscreens, whether on a smartphone or tablet, began only about 15 years ago. Their use has now become near universal. The question is: how does this affect the cognitive development of a child?

Claims about screen time adversely affecting brain development — some even suggesting it “shrinks the brain” — are not based on scientific evidence. A recent study published in JAMA examines the impact of social media use and cognitive development and places it within the larger context of screen use among children.

Not all screen time is the same

When discussing the impact of screen time among children, it is important to distinguish between active and passive use. Active use includes looking up academic facts, writing articles, editing, or working on projects — activities not conceptually different from spending time in the library, reading books, or listening to lectures. Interactive video games are another example of active use.

Passive use, on the other hand, includes watching television or scrolling through Instagram, TikTok, or Facebook — where the user does not contribute or respond significantly to what is shown on screen.

Thus, when used wisely, screen time can yield intellectual returns and build skills, whereas mindless use produces the opposite effect. The impact also depends on the age of the child, the content viewed, and the level of interaction from parents during the session.

Social media use and cognitive development

In this study, researchers examined 6,556 adolescents and tracked their social media use over four years. The focus was specifically on patterns of social media use, rather than total screen time.

Three patterns emerged. The majority (57%) used social media very little. About 37% started with low use but gradually increased their time on social media. A smaller subgroup (6%) were heavy users throughout the study period. At the end of the observation period, the study participants underwent standardised tests of cognitive function.

Cognition is defined as the brain’s ability to acquire, process, store, and apply information. The study measured specific skills in four main areas: stored knowledge, memory, sustained attention, and speed of thinking. A Total Composite Score was then calculated to give an overall picture of cognitive performance. Brain imaging was not performed.

The study found that adolescents who used social media the least had the highest cognitive scores, while those who used it the most had the lowest. Specifically, increasing social media use was associated with poorer performance in memory and language-related tasks (picture sequence memory, picture vocabulary, and oral reading recognition), as well as a lower overall cognitive composite score. The differences, though measurable, were not large.

Social media use and cognitive development

The JAMA study answers several important questions. By focusing specifically on social media rather than total screen time, it improves upon earlier assumptions that all screen use is harmful. The authors suggest that lower cognition among frequent social media users may not result directly from social media itself but from displacement — time spent online replacing time that could have been devoted to study, reading, or other cognitively enriching activities.

Another factor indirectly involved is sleep. Excessive screen exposure can disrupt melatonin production, leading to poor sleep, which independently affects school performance. Screen time can thus affect cognition both directly and indirectly.

Although the topic continues to evolve, certain facts are well established. Scientific societies recommend that children under 18 months have minimal or no screen exposure — except perhaps for supervised video chatting. Very young children cannot reliably distinguish between virtual and real-world experiences. Rather than looking at phone screens, they require person-to-person interaction through touch, play, and conversation — during which they learn to read facial expressions, listen, speak, and socially interact.

Screens and the developing brain

It is not screen time per se but content, context, and displacement that determine its impact.

Before age two, screens offer no learning benefit and can delay language development by reducing face-to-face interaction. Even parents’ own scrolling matters — it steals the talk and attention young children need most.

Between ages two and five, educational, slow-paced programmes — especially when watched along with a parent — can support vocabulary and school readiness.

For older children, learning games may sharpen certain skills, but endless entertainment and social feeds mainly displace reading and sleep — a case of lost opportunity rather than direct harm.

School-aged children often use screens as part of learning, and when used constructively — especially during shared viewing with parents, teachers, or supervisors — screen time can be seen as an investment rather than an expenditure. However, passive scrolling, especially of short-form videos, can impair concentration and displace productive time. The American Academy of Pediatrics warns that excessive screen use in older children can interfere with sleep, physical activity, and other healthy behaviours.

Video games are a separate topic and were not addressed in this study. Research suggests that frequent exposure to violent media can increase aggression and reduce attention span, particularly in younger children. In older children, controlled use of certain video games may sharpen specific cognitive skills. Such benefits and harms, however, cannot be generalised to all games.

Screen use does not ‘shrink’ the brain

Contrary to claims that touchscreen use causes structural brain changes, studies show that MRI and functional MRI findings in children are consistent with normal developmental processes, not deterioration. The thinning of grey matter seen on MRI as children grow older has occasionally been misinterpreted as a sign of brain damage. In reality, it reflects synaptic pruning — a healthy process in which the brain eliminates redundant connections, making its networks more efficient.

Current evidence shows no structural brain damage or loss of grey matter attributable to screen use. A large MRI analysis from the Adolescent Brain Cognitive Development (ABCD) study found that variations in cortical thickness among high and low screen users were within the expected range for age and development.

Functional MRI studies, which measure brain metabolic activity rather than tissue loss, have shown minor differences in connectivity patterns between children who use screens frequently and those who do not. These alterations represent experience-dependent adaptation — how the brain fine-tunes its wiring in response to repeated behaviours — and are not considered pathological.

The myth of “brain rot”

The term brain rot is often used on social media to describe mental fatigue and loss of focus after prolonged scrolling. It is not a scientific term and does not imply structural brain damage. What people call brain rot is better understood as cognitive exhaustion. Prolonged passive scrolling overstimulates reward circuits and suppresses networks responsible for focus and control. The result is distraction, irritability, and low mood — a temporary imbalance similar to what occurs after any form of mental overexposure. The brain remains intact, and these effects disappear once screen exposure is reduced. The notion of “brain rot” basically exaggerates a short-term functional effect into a false claim of neurological harm.

Constructive versus inappropriate use

In summary, screen time in children should not be seen as a single or monolithic entity. Discussions must differentiate between constructive and inappropriate use, and take into account the child’s age. Constructive uses include academic research, project work, and guided learning activities. Inappropriate use includes excessive gaming and mindless social media scrolling.

Among adolescents, limited use of social media appears to have little or no negative impact on intellectual development, contrary to popular perception. Excessive screen use, on the other hand, affects sleep, cuts into study time, and reduces opportunities for physical activity.

In very young children — especially below 18 months (and ideally up to two years) — all screen time should be avoided. Parents who spend excessive time looking at their own touchscreens interact less with their children, potentially compromising the child’s intellectual development. Therefore, limits should apply to parental screen time as well.

As this is an evolving field, further research will clarify how specific patterns of screen use in childhood influence cognition in later life.