A recent Beyond Blue survey of more than 2,000 teachers identified mental ill-health and excessive screen time as the biggest problems facing their students.

Comments from teachers revealed a perceived lack of social skill development in children and teens. As one wellbeing specialist said, young people:

There's no definitive measure of what constitutes "excessive" screen-time, although research is beginning to suggest four hours per day or more is potentially risky.

Although COVID lockdowns played a role in disrupting normal social learning processes, concerns about social and emotional development in our teens has been bubbling away for some time across cultures that have easy access to screen-based technologies and social media. COVID may have thrown petrol on the flames, but it did not light this fire.

So what is going on? Does overexposure to screens lead to social impairments, and if so, how?

Displacing children's development

The developing brain wires itself to the environment in which it finds itself. The skills you use most often will become almost automatic, such as driving a car. But skills you use infrequently need more concentration and effort, especially if you didn't practice them much when your brain was still developing.

Important social experiences such as emotion recognition, reciprocal play and perspective-taking are potentially being sidelined by screen-time. In other words: when children are preoccupied with their screens, what are they not learning?

"Theory of Mind" is a brain function that allows people to understand the mental states of others. Theory of Mind starts with the realisation that everyone has different perspectives, mental states and understandings of our own.

Read more: Understanding others' feelings: what is empathy and why do we need it?

Developmentally, Theory of Mind explains quite a lot about child and adolescent behaviours.

Most parents recall, with some horror, their toddlers' "terrible twos" stage. One of the reasons for these tantrums is a lack of Theory of Mind, which doesn't kick in until the age of three or four. Toddlers just can't understand why their carers don't have the same perspective as them. "I feel thirsty - why is mum not getting me a drink?" Cue tantrum.

This intense frustration is one factor that drives the development of language, as the toddler finally realises other people don't intuit their every thought or feeling and they need to learn to communicate.

As children grow and develop, Theory of Mind underpins the development of all sorts of social skills, such as recognising others' emotional state and developing empathy. This is crucial to developing friendships, romantic partnerships and other kinds of social relationships as we move through life.

By adolescence, Theory of Mind gets really sophisticated. Teenagers are good at understanding socially complex processes such as lying, masking or amplifying true emotions, socially appropriate behaviours such as when not to take a joke too far, and nuanced language expression.

How does this affect mental health?

A child or teenager without age-appropriate social skills will have difficulty developing and maintaining friendships. Given human beings are, by their nature, social creatures, this may lead to isolation, loneliness and mental health issues.

Social media further inhibits perspective-taking by operating as an echo chamber, where a teen's beliefs, interests and ideas are assessed via algorithms and parroted back to them. Rarely is an alternative idea or perspective presented, and, when it is, a teen with already impaired social-communication skills may react with anxiety instead of interest and curiosity.

Read more: Teens with at least one close friend can better cope with stress than those without

The time young people spend on screens has been linked with an array of mental health issues. Longitudinal research is beginning to demonstrate higher screen time is associated with a raft of social-skill impairments at increasingly early ages.

Brain-imaging research shows higher screen use is associated with lower white matter tracts (the information superhighways of the brain) that underpin language and cognitive skills. In contrast, spending a great deal of time in the outdoors is associated with higher grey matter in regions associated with working memory and attention.

So what can parents and teachers do to help?

In the early years, parents and educators can focus on reciprocal play with lots of turn-taking and emotional engagement. When reading books or discussing everyday social interactions, talk about what you or another person was thinking or feeling and how that was expressed.

Delay any form of social media engagement for as long as possible. Encourage your child to critically think about people's agendas when posting online: what are they really trying to get across, what is their motivation, what are they selling? Focus on building in-real-life friendships at school, your local community or sporting club, and within families.

Overall, limiting screen time and encouraging in-real-life play and an array of social engagement opportunities is the best way to improve a child's prospects of developing good social-emotional skills.

Authors: Rachael Sharman - Senior Lecturer in Psychology, University of the Sunshine Coast | Michael Nagel - Associate Professor - Child Development and Learning, University of the Sunshine Coast