Governments push for teen social media bans, amid scientific debate over the move

As governments worldwide move to restrict teenagers’ access to smartphones and social media, a fierce scientific debate has erupted over whether these digital technologies actually harm young people’s mental health.

The controversy, sparked by an influential recent book blaming phones for rising youth anxiety, has exposed deep uncertainties in the research evidence – even as policymakers from the US state of Arkansas to Australia forge ahead with

sweeping bans and restrictions.

Controversy timeline

In March, New York University social psychologist Jonathan Haidt published a popular science book called The Anxious Generation. This blames a rise in youth mental illness over the past 15 years or so on the advent of smartphones and social media.

One early review of Dr Haidt’s book by Duke University psychological scientist Candice Odgers, published in Nature, voiced a common criticism among expert readers: While social media is sometimes associated with bad outcomes, we don’t know if it causes those bad outcomes.

In April, Dr Haidt responded that some recent experimental studies, where researchers got people to reduce their social media use, showed a benefit.

In May, Stetson University psychologist Christopher Ferguson published a “meta-analysis” of dozens of social media experiments and found, overall, that reducing social media use had no impact on mental health.

Next, in August, Dr Haidt and his colleague Zach Rausch published a blog post arguing that Dr Ferguson’s methods were flawed. They said doing the meta-analysis in a different way showed social media really did affect mental health.

Not long afterwards, one of us (Matthew B. Jane) published his own blog post, pointing out issues in Dr Ferguson’s original meta-analysis but showing Dr Haidt and Dr Rausch’s re-analysis was also faulty.

This post also argued that properly re-analysing Dr Ferguson’s meta-analysis still did not provide any convincing evidence that social media affects mental health.

In response to Mr Jane, Dr Haidt and Dr Rausch revised their own post. In September and October, they came back with two further posts, pointing out more serious errors in Dr Ferguson’s work.

Mr Jane agreed with the errors Dr Haidt and Dr Rausch found, and has set out to reconstruct Dr Ferguson’s database (and analyses) from scratch.

The discussion and further work is still ongoing. Yet another team has recently published an analysis (as a pre-print, which has not been independently verified by other experts) disagreeing with Dr Ferguson, using similarly unreliable methods as Dr Haidt and Dr Rausch’s first blog post.

Evidence is varied, but not very strong

Why so much debate? Part of the reason is that experiments where researchers get people to reduce their social media use produce varied results. Some show a benefit, some show harm, and some show no effect.

But the bigger issue, in our opinion, is simply that the evidence from these experimental studies is not very good.

One of the experiments included in Dr Ferguson’s meta-analysis had some German Facebook users reduce their use of the social media platform for two weeks, and others continue using it normally. The participants then had to self-report their mental health and life satisfaction.

People who were asked to use Facebook less did report spending less time on the platform. However, there was no detectable impact on depression, smoking behaviour or life satisfaction at any time point between the two groups. There was a difference in self-reported physical activity, but it was very small.

Another famous study recruited 143 undergraduate students and then randomly assigned them to either limit their Facebook, Snapchat and Instagram use to 10 minutes per day for a month, or to make no changes. The researchers then asked participants to report their anxiety, depression, self-esteem, autonomy, loneliness, fear of missing out and social support.

At the end of the month, there was no difference between the two groups on most measures of mental health and well-being. Those who reduced social media use showed a small decrease in self-reported loneliness, and there was also a small improvement in depression scores among people who reported high levels of depression to begin with.

Existing experiments cannot answer big questions

Studies like these address narrow, specific questions. They are simply unable to answer the big question of whether long-term reduction in social media use benefits mental health.

For one thing, they look at specific platforms rather than overall social media use. For another, most experiments do not really define “social media”. Facebook is obviously social media, but what about messaging services such as WhatsApp, or even Nintendo’s online gaming platform?

In addition, few, if any, of these studies involve interventions or outcomes that can be measured objectively. They consist of asking people – often undergraduate students – to reduce their social media use, and then asking them how they feel. This creates a range of obvious biases, not least because people may report feeling differently based on whether they were asked to make changes in their life or not.

In a medical study assessing a drug’s effect on mental health, it is common to administer a placebo – a substitute that should not have any biological effect on the participant. Placebos are a powerful way to mitigate bias because they ensure the participant does not know if they actually received the drug or not.

For social media reduction studies, placebos are virtually impossible. You cannot trick a participant into thinking they are reducing social media when they are not.

Individual changes and a social problem

What’s more, these studies all work at the level of changes to the behaviour of an individual. But social media is fundamentally social. If one college class uses Instagram less, it may have no impact on their mental health even if the platform is bad, because everyone around them is still using it as much as ever.

Finally, none of the studies looked at teenagers. At present, there is simply no reliable evidence that getting teenagers to use social media less has an impact on their mental health.

Which brings us back to the fundamental question: Does reducing social media improve teen mental health? With the current evidence, we don’t think there’s any way to know.