Screens have become part of the background of modern family life. Televisions glow in living rooms. Tablets sit within easy reach. Smartphones are rarely far from a parent’s hand. For many households, screens feel unavoidable, even during a child’s earliest months.

A new long‑term study now suggests that this everyday exposure may have deeper consequences than previously realised, shaping how the brain develops and potentially increasing the risk of anxiety years later.

The research done in Singapore, published in eBioMedicine, a Lancet Discovery Science, traces a striking developmental pathway from infancy to adolescence. It links higher levels of screen time in the first two years of life to changes in brain network development in early childhood, slower decision‑making in mid‑childhood, and greater anxiety symptoms during the teenage years.

The findings add a new layer of biological evidence to ongoing concerns raised by public health agencies about early screen exposure.

At the heart of the study is an ambitious effort to follow children over more than a decade. Scientists used data from the Growing Up in Singapore Towards healthy Outcomes study, a large birth cohort designed to examine how early life experiences shape long‑term health.

From this cohort, researchers focused on 168 children who had detailed information available at multiple timepoints, spanning infancy, childhood, and adolescence.

Parents reported how much time their children spent on screens when the children were one and two years old. These estimates included televisions, smartphones, tablets, and other digital devices.

Years later, the same children underwent repeated brain scans between the ages of four and seven. At age eight and a half, their decision‑making abilities were assessed using a structured cognitive task. At thirteen, the children completed a standardised questionnaire measuring anxiety symptoms.

This layered design allowed scientists to move beyond simple associations. Rather than asking whether screen time and anxiety are linked, the study explored how early screen exposure might influence brain development and behaviour in ways that later increase vulnerability to anxiety.

The brain is not a single, uniform organ. It is organised into networks that specialise in different functions. Some networks process vision. Others manage attention, emotional regulation, or cognitive control. During early childhood, these networks undergo rapid change. Connections are strengthened. Others are pruned away. Over time, networks become more specialised and efficient.

Using diffusion magnetic resonance imaging, researchers mapped how these brain networks developed across three separate timepoints. They focused on a measure known as network integration, which reflects how strongly different networks communicate with each other. In typical development, certain networks gradually become less integrated with others as they specialise.

One network pair stood out. Higher screen time during infancy was associated with a steeper decline in integration between the visual network and the cognitive control network between the ages of four and seven. This pattern suggests that these networks separated more quickly than usual, a process often described as accelerated maturation.

At first glance, faster development may sound positive. Yet brain development follows a delicate timetable. When changes happen too early or too quickly, flexibility may be lost. The brain may become less adaptable to new demands. Experts caution that timing matters as much as direction.

Importantly, this association was specific to screen exposure in infancy. Screen time measured later, during the preschool years, showed no link to changes in brain network development. This finding highlights the first two years of life as a particularly sensitive period, when the brain is highly responsive to environmental input.

The study did not stop at brain structure. The researchers then examined whether these neural changes had practical consequences for behaviour. To do this, they analysed performance on the Cambridge Gambling Task, a widely used tool that assesses decision‑making.

In this task, children are shown rows of coloured boxes and must decide where a hidden token is likely to be. They then choose how many points to bet on their decision. The task measures several aspects of decision‑making, including risk‑taking, impulsivity, and accuracy.

One measure stood out. Deliberation time. This reflects how long a child takes before making a decision.

Children who showed faster separation of the visual and cognitive control networks took longer to decide, even when the information was clear and fixed. Taking more time did not improve accuracy. The delay appeared to reflect slower processing or hesitation rather than careful strategy.

This detail matters. In many real‑world situations, prolonged hesitation can increase stress, especially in uncertain environments. Over time, such patterns may contribute to anxious thinking.

The final piece of the puzzle was mental health in adolescence. When researchers examined anxiety scores at age thirteen, they found a clear link between longer decision‑making times in childhood and higher anxiety symptoms in the teenage years.

When all these factors were analysed together, a single pathway emerged. Higher screen time in infancy predicted faster separation of specific brain networks. These brain changes predicted longer decision‑making times in mid‑childhood. Longer decision‑making times predicted higher anxiety in adolescence.

The direct link between infant screen time and teenage anxiety was not significant. Instead, the effect unfolded gradually across development. This finding suggests that early screen exposure may plant subtle changes that only become visible years later.

Experts believe sensory processing may play a central role. Screens deliver intense visual stimulation, often without the rich sensory feedback that comes from physical play, face‑to‑face interaction, or exploration.

During infancy, when the brain is learning how to integrate sensory input with control and regulation systems, heavy screen exposure may shift this balance.

Over time, this altered sensory experience may influence how children process information, make decisions, and respond to uncertainty. Anxiety disorders are frequently linked to heightened sensitivity and difficulty managing ambiguous situations, which aligns with the observed patterns.

The findings resonate with earlier research showing links between screen use and changes in white matter, cortical thickness, and sensory processing. However, most previous studies relied on cross‑sectional data. This new work stands out because it captures brain development as a moving process rather than a static snapshot.

The researchers were careful to note the study’s limitations. Screen time was reported by parents, which may introduce some inaccuracy. The study did not differentiate between types of screen content or whether screens were used alone or with caregivers. Other factors, such as sleep quality, family mental health history, and parent‑child interaction, were not fully accounted for.

The study was also observational. It cannot prove cause and effect. The pathway identified is plausible and biologically coherent, but alternative explanations remain possible. The authors describe the findings as an important step rather than a final answer.

Even so, the implications are significant. Global screen use among infants and young children has increased sharply over the past decade. Public health bodies have repeatedly warned that screen exposure before the age of two should be avoided where possible. This study adds weight to those recommendations by offering a potential explanation for why early exposure may matter.

For families, the message is not one of alarm. Screens are woven into modern life. Many parents rely on them for communication, work, and occasional relief. Instead, the findings encourage thoughtful use, especially during the earliest years when the brain is most sensitive.

Experts emphasise the value of sensory‑rich, interactive experiences in infancy. Talking, reading, singing, playing, and exploring the physical world provide the kind of input that supports balanced brain development. These activities engage multiple senses at once and strengthen the links between perception, action, and emotion.

The study also points towards possible avenues for early intervention. If sensory processing plays a role in later anxiety, supporting healthy sensory development in early childhood may reduce risk. This could include encouraging varied play, outdoor activity, and responsive caregiver interaction.

From a public health perspective, the findings arrive at a critical moment. Screen exposure surged during the COVID‑19 pandemic, even among very young children. As societies reflect on the long‑term effects of this shift, evidence that traces early exposure to adolescent mental health becomes especially relevant.

The research underscores a broader message. Early life experiences do not simply fade away. They become embedded in the developing brain, shaping how children think, feel, and cope years later. Small, everyday habits can have long shadows.

As scientists continue to untangle the complex relationship between technology and child development, studies like this help move the conversation beyond opinion and fear. They provide data, context, and biological insight.

For parents, educators, and policymakers, the takeaway is clear. The earliest years deserve special protection. Screens may be useful tools, but they are not neutral. How and when they are introduced matters.

In a world filled with digital noise, this research offers a quiet reminder. The developing brain thrives on real‑world connection, rich sensory input, and time to grow at its own pace. That may be one of the most important investments in a child’s future wellbeing.