New government research has revealed a significant link between high levels of screen time and poorer vocabulary development in very young children. The findings have prompted ministers to announce the first official guidance on screen use for the under-fives, due in April.
Government Study Uncovers Vocabulary Gap
The crucial data comes from The Children of the 2020s (COT20s) study, a major longitudinal research project. Between October 2023 and February 2024, primary caregivers of children aged around two years old (between 24 and 28 months) were asked to complete an online survey. In total, 4,758 surveys were completed.
The results were stark. Children in the highest screen time group, who averaged around five hours a day, could say, on average, only 53% of a set of 34 test words. This compared to children in the lowest screen time group, who averaged just 44 minutes per day and could say 65% of the words.
Why Children's Brains Are More Vulnerable
Experts warn that children are far more susceptible to the effects of screen exposure than adults. Dr Samir Shah, a consultant psychiatrist and medical director at Priory Hospital Altrincham, explains that children's brains are like sponges, soaking up experiences at an incredible rate. He highlights that key developmental periods, particularly before age five, are times of the most rapid brain growth.
Professor Torkel Klingberg, a cognitive neuroscience expert at the Karolinska Institutet, agrees. He emphasises that childhood is a crucial time of neuroplasticity, where the development of cognitive abilities lays the foundation for future education and adult performance.
Five Key Impacts on the Developing Brain
1. Damages Attention Span and Focus
Professor Klingberg points to a large study of over 8,000 children aged 10 to 14, which found that time spent on social media was specifically associated with increased symptoms of inattention. These children reported problems focusing for long periods, being easily distracted, and struggling to complete homework.
2. Harms Mood and Mental Health
Dr Shah highlights research showing that children and teenagers who spend more than four hours daily on screens are more likely to experience higher levels of anxiety and depression. The constant digital stimulation can lead to overstimulation and emotional unfulfilment. It can also impair a child's ability to manage frustration and pick up on vital social cues, reducing opportunities to practise empathy and conflict resolution.
3. Leads to Sleep Deprivation
Screen time often crowds out essential activities like sport, in-person interaction, and critically, sleep. Professor Klingberg stresses the vast body of research showing the importance of sleep for psychological wellbeing and cognitive performance, especially in young, growing brains. Lack of sleep can negatively affect long-term memory, attention, and working memory.
4. Impairs Problem-Solving and Memory
The constant distractions online deprive children of the chance to focus deeply and engage in the cognitive challenges that drive development. Professor Klingberg notes that working memory, which can be trained and developed, may suffer. He advocates for reducing social media use in favour of more focus-demanding activities like reading.
5. Disrupts Natural Reward Systems
Dr Shah explains that screens regularly trigger the release of dopamine, the brain's 'feel-good' chemical. This creates a cycle where children crave more screen time to get the same buzz. Over time, real-world activities can feel less rewarding by comparison, making it harder for regular screen users to build and maintain meaningful social connections.
The government's forthcoming guidance, set for release in April 2026, will aim to help parents navigate these complex challenges and protect their children's crucial early development.
