The link between teen girls’ mental health and social media usage is not just correlational, argues an NYU-Stern professor: There is now solid evidence that it is causal. In a section titled Why is it so hard to prove that social media and smartphones are destroying teen mental health? he noted that “the academic literature on social media’s harms is complicated” and he then quoted one of the main academics studying the issue—Jeff Hancock, of Stanford University: “There’s been absolutely hundreds of [social-media and mental-health] studies, almost all showing pretty small effects. Euractiv that the action was “misguided” and based on “fundamental misconceptions