Josh MacAlister

I thank my hon. Friend for his work on this issue in his constituency. He is absolutely right. Micro-experiments and anecdotal feedback from members of the public, who have signed this petition in large numbers, show that parents are really worried that something is going on here, but it will take some time to gather the evidence. The second aspect is about where the burden of proof should lie. Applying the burden of proof in one direction only—to those advocating for tighter regulation—is not balanced. It should apply both ways. The third point about evidence relates to the absence of causal studies. They will take many years, so what do we do, in their absence, with the weight of correlational evidence before us? This is where we must look at the work of Sir Austin Bradford Hill. The Bradford Hill criteria, which were named after him in the 1960s, were based on the epidemiologist’s work to try to fill in the evidence gap for policymakers when the debate was being had about the public health impacts of smoking. The tobacco industry did a very effective job of casting doubt over whether smoking itself caused cancer or, as the industry then said, it simply brought cancer out earlier—that cancer was inherent within people. That was the argument: the industry said that there was no correlational study to prove that that was not the case, which goes back to my burden of proof argument. We need to fill in the gap, because we will not have causal studies for many years. Petitions like this will continue to come, the debate will carry on raging, and politicians will be pulled towards this problem until we find a way of solving it. In the absence of those correlational studies, we have to find a way of applying a framework to look at the existing causal studies. I will not go through all nine of the Bradford Hill criteria, but one of them is dose-response rate: does the dose of a certain factor relate to the degree of the impact? In 2019, the UK millennium cohort study found that “social media use is associated with mental health in young people”, and greater use means greater impact. A 2022 dose-response meta-analysis found that more time spent on social media was “significantly associated” with depression. There are stacks of studies out there that show the correlation between time spent and impact. When one works through the nine criteria, in the absence of a causal study or series of causal studies, the evidence points in a clear direction: we need tighter regulation that can empower parents to set boundaries and the collective rules for how our children use smartphones and social media. There is a risk, at times, that the sides to this debate are characterised as pro- or anti-tech. My final reflection is that, for the UK to be the global sandbox and incubator of great tech development that it should be, we need good, intuitive shared rules that can garner high degrees of public consent and support. If we move quickly on this issue, and do it smart, as a country, we will get benefits not only for economic growth and the tech industry, but for our children and their future.