What Screen Time Does to the Child's Brain: Two New Studies

It is a scene most parents know well: the toddler fusses at the supermarket, in a restaurant, or in the waiting room – and a quick handover of the phone restores calm. The screen soothes instantly, no one is disturbed, everyone breathes a little easier. But what if those quiet minutes leave traces we cannot see?

Two new studies from 2025 looked at exactly that – not behaviour, but the brain itself. Using brain scans and long-term data from thousands of children, they offer the first solid evidence of how early and how deeply screen time can shape development. The findings deserve to be taken seriously, but they are no reason to panic. Quite the opposite: they show, with surprising precision, where parents can truly make a difference.

Two Studies, One Clear Signal

For a long time, the screen time debate revolved almost entirely around minutes and hours. These new studies dig deeper and ask what actually happens inside a child's head.

The first study comes from the A*STAR Institute for Human Development and Potential and the National University of Singapore, published in late December 2025 in the journal eBioMedicine¹. A research team led by Pei Huang and Tan Ai Peng followed children over several years, taking brain scans at three points in time – at ages 4.5, 6, and 7.5. This allowed them to capture not just a single snapshot, but development over time.

The second study, published in October 2025 in Translational Psychiatry, is far larger in scale². A team led by Qiulu Shou at the University of Fukui analysed data from 11,878 children aged nine to ten and tracked them over two years. Independently of one another, both studies reach a similar conclusion: screen time is associated with measurable differences in brain structure – and those differences, in turn, with behaviour and wellbeing.

Why the Earliest Years Matter Most

Perhaps the most striking finding of the Singapore study concerns the very youngest children. Those who spent a lot of time in front of screens before their second birthday showed altered maturation of their brain networks. The networks most affected were those responsible for visual processing and cognitive control – in other words, for organising impressions and regulating one's own behaviour.

These networks did not mature more slowly, but faster and less efficiently. What might sound like an advantage is anything but: the brain effectively skips important developmental steps. The researchers were able to link these early changes to slower decision-making and to heightened anxiety in adolescence – effects that were still measurable years later.

Especially revealing is what the study did not find: in children whose screen time was first measured at age three or four, these patterns did not appear to the same degree. This suggests that infancy and early toddlerhood form a particularly sensitive window. In the first two years of life, the brain builds connections at a remarkable pace – and depends heavily on real, living interaction to do so.

This is exactly where the World Health Organization (WHO) draws the line. It recommends no screen time at all for children under two, and no more than one hour a day for those aged two to four – the less, the better³. The new brain data now give that recommendation a biological foundation.

When Screen Time Affects Attention

The second study looks at older children and paints an equally clear picture. Among the nine- to ten-year-olds, more screen time was associated with more pronounced ADHD symptoms – that is, inattention, impulsivity, and restlessness.

Here too, the researchers found structural differences in the brain:

A smaller right putamen – a region linked to learning, reward, and addictive behaviour
A thinner cortex in the right temporal pole, which is important for processing language and social cues
A smaller cerebral cortex overall, the outer layer responsible for higher-order thinking and attention

The timing is the crucial part: children who spent a lot of time on screens at nine or ten showed stronger ADHD symptoms two years later – even after accounting for their initial symptoms. This suggests that screen time may be not merely a by-product, but a contributing factor.

An important caveat: studies like these show associations, not simple cause-and-effect chains. No single child becomes a risk case because of one hour on a tablet. But the broad data pattern is clear enough to take seriously.

Not Just How Long, but How

Anyone alarmed by this should also know a second, more hopeful finding from the Singapore study. Among children whose parents read to them regularly at age three, the link between early screen time and altered brain development was significantly weaker.

This is more than a pleasant side note. It shows that screen time alone is not what counts, but the child's entire environment of experience. Shared reading offers precisely what passive media consumption cannot: a back-and-forth of language, eye contact, and emotion – a real relationship unfolding in real time.

From this follows an important distinction:

Passive use – sitting alone in front of autoplaying videos – gives the brain little to engage with
Active, accompanied use – watching something together, talking about it, asking questions – turns screen time into shared experience
Analogue counterweights – reading, playing, movement, conversation – strengthen exactly the abilities that suffer under too much passive consumption

The American Academy of Pediatrics (AAP) likewise advises parents to focus less on the clock and more on what a child is doing and whether they are left alone to do it⁴. When in doubt, quality beats quantity.

What Parents Can Do Now

The good news: both studies point to clear, achievable conclusions. The goal is not perfect screen-freedom, but deliberate everyday choices.

For the Earliest Years (0–5)

Avoid screens before the second birthday where possible, and do not establish them as a soothing tool
Make reading aloud a daily ritual – current research identifies it as one of the most effective protective factors of all
Stay present during screen time and put what you see into words together, rather than leaving the child alone with the device

For School Age and Beyond

Create fixed screen-free zones – meals, the bedroom, and the hour before sleep stay screen-free
Talk about content instead of just counting minutes: what is my child playing, watching, interested in right now?
Plan movement and real encounters deliberately as a counterweight
Grant responsibility step by step as the child grows older

Resources like Common Sense Media stress that such agreements work best when they are made together with the child and adjusted regularly to their age⁵. That keeps rules understandable and durable.

What helps most of all is transparency – for parents and children alike. Tools like FamFlow make actual media use visible and create a shared basis for conversation. When a child sees their own time budget on a dashboard, discussions rest on facts rather than on a vague sense of "too many hours".

Precisely because research shows that the deliberate shaping of screen time matters as much as its duration, such an overview can be valuable. With FamFlow, a vague "too much phone" becomes a concrete prompt to think together about how the rest of the day should look.

Conclusion: Early Choices, Lasting Impact

Two new studies, two clear signals: screen time leaves measurable traces in the developing brain – especially in the earliest years, and especially when it happens passively and alone. Altered brain networks, more anxiety, stronger attention difficulties: these findings deserve attention, without plunging parents into guilt or fear.

Because the same studies also point to a way out. A brain is not a rigid system; it grows through relationship and real experience. Reading aloud, watching together, conversation, movement – all of these actively counter the risks. It is not the screen alone that shapes a child, but the life around it.

So take these new insights not as a stop sign, but as a signpost. Parents who prioritise genuine closeness in the early years and seek out conversation about media later on give their child the best that research has to offer: a brain that gets to develop in a rich, living world.

A*STAR & National University of Singapore – "Neurobehavioural links from infant screen time to anxiety", eBioMedicine (The Lancet), December 2025: thelancet.com/journals/ebiom/article/PIIS2352-3964(25)00543-2/fulltext ↩
Shou et al. – "Association of screen time with attention-deficit/hyperactivity disorder symptoms and their development", Translational Psychiatry, October 2025: nature.com/articles/s41398-025-03672-1 ↩
WHO – Guidelines on Physical Activity, Sedentary Behaviour and Sleep for Children under 5 Years of Age: who.int/publications/i/item/9789241550536 ↩
American Academy of Pediatrics – Media and Children: aap.org/en/patient-care/media-and-children ↩
Common Sense Media – Screen Time Guidance for Parents: commonsensemedia.org/articles/screen-time ↩