The other day, while I was doing some household chores, I handed my youngest child his dad's iPad to keep him entertained.
But after a while I suddenly felt uneasy: I wasn't 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 didn't let his own children have them. Bill Gates has said he restricted his children's 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 weren't 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 Greenfield's 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?
Is it really as bad as it seems?
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 isn't 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.
Problems with the science
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, let's 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.
Doomscrolling vs uplifting screen time
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 don't… so this idea that screens are changing brains in a consistently or enduringly bad way, that just doesn't 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 wouldn't be here.
"We'd have been selected for extinction a very long time ago."
'Terrible formula for mental health'
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.
