The harms of social media design are so clear that the “burden of proof” for safer features must fall on the companies themselves, rather than parents or policymakers, a technology psychologist has told MPs.
During its inquiry into neuroscience and digital childhoods on 24 June, the Science, Innovation and Technology Committee was told by Ravi Iyer, managing director of the Psychology of Technology Institute at the University of Southern California, that the UK’s age limit policy should be tied to harmful design features.
“In every country, there is an age where you let kids do things that they know are harmful to themselves … I do not think we have thought of that for social media,” Iyer said, adding that “the harms are so clear right now that presuming that they are unsafe and then forcing the burden of proof to be on the companies” is the quickest route to effective harm reduction.
Instead of regulating the behaviour of young people, he considers restrictions on design features to be “regulating the contractual relationship” between tech companies and people, as children give away their data and consent to design features to access the digital world.
This includes design decisions built to keep people hooked, such as engagement-based algorithms, gamification and frictionless interfaces like infinite scroll or autoplay, which “do not give you the chance to reconsider” using these products.
He added that if the UK government wants to protect under-16s for this amalgamation of harmful design features, “a great way to start is by presuming that the platforms that have this combination of features are harmful until they remove these features, rather than trying to pick out these features one by one”.
Iyer – who previously worked at Meta for four years – said if there is a presumption that social media platforms are harmful, “then the platforms have to prove themselves safe by showing that they do not have certain design features”.
While platforms have historically argued on the safety of specific design features, he said, introducing age limits tied to harmful design features – as has taken place in Indonesia and Canada – “shifts the burden of proof from policymakers to the companies”, which must be able to show that their products are safe.
He added that, in his experience of speaking to people at the large social media firms, the pressure placed on these platforms by age-limit policies is positively influencing design decisions that are beneficial for all users, not just under-16s.
“Once you prove that these design features are harmful for kids, it is natural to also show that these design features are harmful for others,” he said.
“I do not think there is any tension between age-limiting these platforms for under-16s and putting pressure on companies in terms of design. I think you can do both, and in practice, they have been complementary in every other jurisdiction that I have experience in.”
How does social media use impact children?
Head of UK affairs for children’s online rights campaign group 5Rights Foundation, Colette Collins-Walsh, told the inquiry: “The way the platforms are designed infringes on their agency to put [their device] down. This is something we hear a lot from children. They say, ‘I feel addicted or wish I could put my phone down.’”
A US survey by the World Happiness Report (WHR) found that half of Gen Z adults (ages 18 to 27), who grew up with social media, wished TikTok had never been created, with 34% saying the same about Instagram. On the other hand, significantly fewer Gen Zs regret the creation of products that offer longer-form content, such as YouTube and Netflix.
Young people are failing to regulate their use of social media. Meta, for example, built its products with a “social-validation feedback loop”, said Facebook’s founding president, Sean Parker, in 2017. “It’s … exactly the kind of thing that a hacker like myself would come up with, because you’re exploiting a vulnerability in human psychology.”
A recent court case brought against Meta by Breathitt School District in the US – settled in May 2026 – showed that Meta was aware that social media addiction was “particularly salient for its youngest users” because teenage brains are “more sensitive to dopamine” so young people “have a much harder time stopping even though they want to”.
For example, the increasing problem of lack of sleep in young people is facilitated by overnight notifications, said Iyer. The Pew Research Centre found that social media negatively affected sleep in 50% of the teenage girls surveyed.
With lack of sleep consistently found to impact brain development, Iyer said companies like Meta should be researching whether a product intervention or a policy change affects the amount of sleep kids get, to understand whether children are receiving notifications late at night or using its products between midnight and 5am.
Demonstrating that products do not have harmful features, such as late-night notifications, can be a way to prove their safety. “We can definitely isolate those product choices and affect them through good policy,” said Iyer.
“Just like a food manufacturer would demonstrate that something does not have things that are known to cause cancer or other problems, a product designer should also demonstrate that a product does not have features that are known to be designed to cause harm to kids.”
Research by Meta and external researchers has proven a significant negative impact on young people. Over a third of teen girls reported “often or always seeing posts that made them feel worse about their bodies, compared to 26% of users overall”, according to internal Meta research.
