What screen time does to childrens brains is more complicated than it seems

The other day, while I was doing some household chores, I handed my youngest child his dads iPad to keep him entertained. But after a while I suddenly felt uneasy: I wasnt keeping a close eye on how long he had spent using it or what he was looking at. So I told him it was time to stop.

A full-blown tantrum erupted. He kicked, he yelled, he clung to it and tried to push me away with the might of a furious under-five. Not my finest hour as a parent, admittedly, and his extreme reaction bothered me.

My older children are navigating social media, virtual reality and online gaming, and sometimes that concerns me too. I hear them tease each other about needing to "touch grass" – disconnect from the tech and get outdoors.

The late Steve Jobs, who was CEO of Apple when the firm released the iPad, famously didnt let his own children have them. Bill Gates has said he restricted his childrens access to tech too.

Screen time has become synonymous with bad news, blamed for rises in depression in young people, behavioural problems and sleep deprivation. The renowned neuroscientist Baroness Susan Greenfield went as far as to say that internet use and computer games can harm the adolescent brain.

Back in 2013 she compared the negative effects of prolonged screen time to the early days of climate change: a significant shift that people werent taking seriously.

Plenty of people are taking it more seriously now. But warnings about the dark side might not tell the full story.

An editorial in the British Medical Journal argued that Baroness Greenfields claims around the brain were "not based on a fair scientific appraisal of the evidence… and are misleading to parents and the public at large".

Now, another group of UK scientists claim that concrete scientific evidence on the downsides of screens is lacking. So have we got it wrong when it comes to worrying about our children and curbing their access to tablets and smartphones?

Pete Etchells, a psychology professor at Bath Spa University, is one of the academics in the group arguing that the evidence is lacking.

He has analysed hundreds of studies about screen time and mental health, along with large amounts of data about young people and their screen habits. In his book Unlocked: The Real Science of Screen Time, he argues that the science behind the headline-grabbing conclusions is a mixed bag and, in many cases, flawed.

"Concrete scientific evidence to back up stories about the terrible outcomes of screen time simply isnt there," he writes.

Research published by the American Psychology Association in 2021 told a similar story.

The 14 authors, from various universities around the world, analysed 33 studies published between 2015 and 2019. Screen use including smartphones, social media and video games played "little role in mental health concerns", they found.

And while some studies have suggested blue light - such as that emitted by screens - makes it harder to drift off because it suppresses the hormone melatonin, a 2024 review of 11 studies from around the world found no overall evidence that screen light in the hour before bed makes it more difficult to sleep.

One big problem is that most of the data on the subject of screen time relies heavily on "self-reporting", Prof Etchells points out. In other words, researchers simply ask young people how long they think they spent on their screens, and how they remember it making them feel.

He also argues there are millions of possible ways to interpret these large amounts of data. "We have to be careful about looking at correlation," he says.

He cites the example of a statistically significant rise in both ice cream sales and skin cancer symptoms during the summer. Both are related to warmer weather but not to each other: ice creams do not cause skin cancer.

He also recalls a research project inspired by a GP who noticed two things: first, they were having more conversations with young people about depression and anxiety, and second, lots of young people were using phones in waiting rooms.

"So we worked with the doctor, and we said, OK, lets test this, we can use data to try and understand this relationship," he explains.

While the two did correlate, there was a significant additional factor: how much time those who were depressed or anxious spent alone.

Ultimately, it was loneliness that was driving their mental health struggles, the study suggested, rather than screen time by itself.

Then there are the missing details about the nature of the screen time itself: the term is far too nebulous, argues Prof Etchells.

Was it uplifting screen time? Was it useful? Informative? Or was it "doomscrolling"? Was the young person alone or were they interacting online with friends?

Each factor generates a different experience.

One study by US and UK researchers looked at 11,500 brain scans of children aged 9 to 12 alongside health assessments and their own reported screen time use.

While patterns of screen use were linked to changes in how brain regions connect, the study found no evidence that screen time was linked to poor mental well-being or cognitive issues, even among those using screens for several hours of the day.

The study, which ran from 2016 to 2018, was supervised by Oxford University Professor Andrew Przybylski, who has studied the impact of video games and social media on mental health. His peer-reviewed studies indicate that both can, in fact, boost wellbeing rather than damage it.

Prof Etchells says: "If you think that screens do change brains for the worse, you would see that signal in a big data set like that. But you dont… so this idea that screens are changing brains in a consistently or enduringly bad way, that just doesnt seem to be the case."

This view is echoed by Professor Chris Chambers, head of brain stimulation at Cardiff University, who is quoted in Prof Etchells book as saying, "It would be obvious if there was a decline.

"It would be easy to look at the last, say, 15 years of research… If our cognitive system was so fragile to changes in the environment, we wouldnt be here.

"Wed have been selected for extinction a very long time ago."

Neither Prof Przybylski nor Prof Etchells dispute the grave threat of certain online harms, such as grooming and exposure to explicit or harmful content. But both argue that the current debate around screen time is in danger of driving it further underground.

Prof Przybylski is concerned about arguments for limiting devices or even banning them - and believes that the more rigidly screen time is policed, the more of a "forbidden fruit" it could become.

Many disagree. The UK campaign group Smartphone Free Childhood says 150,000 people have so far signed its pact to ban smartphones for children below the age of 14, and delay social media access until the age of 16.

When Jean Twenge, a professor of psychology from San Diego State University, began researching rising depression rates among US teenagers, she did not set out to prove that social media and smartphones were "terrible," she tells me. But she found it to be the only common denominator.

Today, she believes separating children and screens is a no-brainer, and is urging parents to keep children and smartphones apart for as long as possible.

"[Childrens] brains are more developed and more mature at 16," she argues. "And the social environment at school and friend groups is much more stable at 16 than it is at 12."

While she does agree that the data gathered on young peoples screen use is largely self-reported, she argues that this does not dilute the evidence.

One Danish study published in 2024 involved 181 children from 89 families. For two weeks, half of them were limited to three hours of screen time per week and asked to hand in their tablets and smartphones. It concluded that reducing screen media "positively affected psychological symptoms of children and adolescents" and enhanced "prosocial behaviour", although added that further research was needed.

And a UK study in which participants were asked to record time diaries of their screen time found that higher social media use aligned with higher reported feelings of depression in girls.

"You take that formula: More time online, usually alone with a screen; less time sleeping; less time with friends in person. That is a terrible formula for mental health," says Prof Twenge.

"I have no idea why thats controversial."

When Prof Etchells and I speak, it is via video chat. One of his children and his dog wander in and out. I ask whether screens are really re-wiring childrens brains and he laughs, explaining that everything changes the brain: thats how humans learn.

But he is also clearly sympathetic towards parental fears about the potential harms.

It doesnt help parents that there is little clear guidance - and that the topic is fraught with bias and judgement.

Jenny Radesky, a paediatrician at the University of Michigan, summed this up when she spoke at the philanthropic Dana Foundation. There is "an increasingly judgmental discourse among parents," she argued.

"So much of what people are talking about does more to induce parental guilt, it seems, than to break down what the research can tell us," she said. "And thats a real problem."

Looking back, my youngest childs tantrum over the iPad alarmed me at the time - but on reflection Ive experienced similar performances over non-screen related activities: like when he was playing hide and seek with his brothers and didnt want to get ready for bed.

Screen time comes up a lot in my conversations with other parents too. Some of us are stricter than others.

The official advice is currently inconsistent. Neither the US American Academy of Paediatrics nor the UKs Royal College of Paediatrics and Child Health recommend any specific time limits for children.

The World Health Organization, meanwhile, suggests no screen time at all for children below the age of one, and no more than one hour per day for under-fours (although when you read the policy this is aimed at prioritising physical activity).

There is a bigger issue here in that there is simply not enough science to make a definitive recommendation, and this is dividing the scientific community - despite a strong societal push to limit childrens access.

And without set guidelines, are we setting up an uneven playing field for children who are already tech-savvy by adulthood, and others who are not and are arguably more vulnerable as a result?

Either way, the stakes are high. If screens really are damaging children, it might be years before the science catches up and proves it. Or if it eventually concludes that it isnt, we would have wasted energy and money and, in the process, tried to keep children away from something that can also be extremely useful.

And, all the while, with screens becoming glasses, social media regrouping around smaller communities, and people using AI chatbots to help with homework or even for therapy - the tech thats already in our lives is rapidly evolving, whether or not we let our children access it.

Illustrator: Jodi Lai

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