Neuroscientists this week offered a blunt reality check to British lawmakers seeking scientific proof that smartphones and social media are damaging children's brains. The evidence, they said, barely exists.

Appearing before the Science, Innovation and Technology Committee, three researchers told MPs that concern about digital childhood has raced far ahead of the causal research needed to settle the debate. Correlation, they repeated, is not causation.

The Evidence Gap

Professor Denis Mareschal, director of the Centre for Brain and Cognitive Development at Birkbeck, said there is very little causal research on how digital devices affect infants and young children. Nearly everything available is correlational, meaning it shows a relationship but cannot prove that screen time causes harm.

Professor Sarah-Jayne Blakemore from the University of Cambridge gave a similar answer for adolescents. She said almost no robust, replicated studies exist on social media's impact on the adolescent brain. The few small studies that do exist are purely correlational.

The researchers did not dismiss concern. Blakemore noted that adolescence brings heightened activity in brain reward systems while self-control regions remain under development. Even adults struggle to put down phones, she said, and children face an even greater challenge.

Displacement Not Brain Damage

Dr Dusana Dorjee, a senior lecturer at the University of York, pointed to a different risk. Children learn self-regulation through conversation, play, sport and social interaction. Excessive screen use, she said, can crowd out those activities. The question is not what screens do to the brain but what children miss when they are on them.

The witnesses refused to treat all screen time the same. Mareschal cited evidence that video calls help families stay connected. Dorjee distinguished educational apps from endlessly scrolling algorithm driven feeds.

Age Limits and Individual Brains

MPs asked whether neuroscience could set a precise age for when children should join social media. Blakemore said it cannot. Individual differences in brain development are vast. Neuroscience cannot pinpoint a single age that applies to every child.

AI Chatbots Enter the Unknown

When the conversation turned to AI companions, the answers became even less certain. Blakemore said there is no evidence on how children interpret AI chatbots, whether they treat them like friends or perceive them differently. She called for urgent new research into how young people understand chatbot behavior and suggestions.

Why This Matters

This testimony lands at a moment when politicians, parents and educators are pushing for tighter regulation of children's digital lives. The hearing shows that policy is being shaped by moral panic rather than hard neuroscience. Without causal evidence, laws and school bans may rest on shaky ground. The real debate, the researchers suggested, should shift from panic to displacement, from brain rewiring to what children lose when screens replace real world interaction.