The central idea of my forthcoming book, The Anxious Generation, is that we have overprotected children in the real world, where they need a lot of free play and autonomy,while underprotecting them online, where they are not developmentally ready for much of what happens to them. Much of my thinking about the importance of free play comes from Peter Gray, a professor of psychology at Boston College who is one of the world’s leading experts on the psychology of play. See his powerful TED talk, where he lays out the evolutionary origins of play—a necessity for all young mammals. He then shows how we have systematically deprived children of free play since the 1970s and shows that adolescents’ mental health has declined substantially over the same period. He notes that this is a correlation, not proof of causation, although experiments with animals support the claim that play deprivation causes anxiety and poor social development.

Peter gave that talk in 2014. Since then, the mental health of children and adolescents has worsened, and evidence has increased showing that Peter was correct. Peter recently published a major review article in the Journal of Pediatrics titled Decline in Independent Activity as a Cause of Decline in Children’s Mental Well-being: Summary of the Evidence. I think it’s among the most important essays ever written on play. I was planning to write a summary of the article for the After Babel Substack, but a few days ago, I got Peter’s own summary of the article, which he posted on his new Substack, Play Makes Us Human, which you can find and subscribe to here:

I asked Peter if I could repost his Substack essay at After Babel. He said yes, and you’ll find it below. Peter and I disagree on whether smartphones and social media are also major causes of the teen mental health crisis, as you’ll see. But we both agree that play deprivation is a major contributing cause and that anyone who is serious about the mental health of children and teens (and adults) should be up in arms about what America and many other countries have done to prevent children from playing in the ways they need and want to play.

I note that Peter is a co-founder, with me, Lenore Skenazy, and Daniel Shuchman, of LetGrow.org, where we both serve on the board. LetGrow offers many resources for parents, schools, and state legislators that want to act on Peter’s advice and introduce more free play and autonomy into children’s lives.

— Jon Haidt

In this letter, I summarize the contents of an article that anthropologist David Lancy, developmental psychologist David Bjorklund, and I published recently in the Journal of Pediatrics. For the full account, including citations to research supporting each point, see the article here. Throughout this letter, I use the term “children” to refer to everyone under 18 years old unless otherwise specified.

We began the article with two very well-established and disturbing facts.

The first fact is that over the past 5 decades or more we have seen, in the United States, a continuous and overall huge decline in children’s freedom to play or engage in any activities independent of direct adult monitoring and control. With every decade children have become less free to play, roam, and explore alone or with other children away from adults, less free to occupy public spaces without an adult guard, and less free to have a part-time job where they can demonstrate their capacity for responsible self-control. Among the causes of this change are a large increase in societal fears that children are in danger if not constantly guarded, a large increase in the time that children must spend in school and at schoolwork at home, and a large increase in the societal view that children’s time is best spent in adult-directed school-like activities, such as formal sports and lessons, even when not in school.

The second undisputed fact is that over these same decades, rates of anxiety, depression, and suicide