One of the topics I’ve returned to repeatedly in my work is the intersection of smartphones and children (see, for example, my two New Yorker essays on the topic, or my 2023 presentation that surveys the history of the relevant research literature). Given this interest, I was, of course, pleased to see an important new study on the topic making the rounds recently: “A Consensus Statement on Potential Negative Impacts of Smartphone and Social Media Use on Adolescent Mental Health.” To better unde...