The evidence that smartphones and social media have had a painful to a catastrophic effect on millions of younger Americans — plunging many into depression, and spurring eating disorders, thoughts of suicide and antisocial behavior — is no longer in dispute. Among the first to persuasively make this case was San Diego State psychology professor Jean M. Twenge in an instantly famous 2017 essay in The Atlantic headlined “Has the smartphone destroyed a generation?” Her thesis: “The advent of the smartphone and its cousin the tablet was followed quickly by hand-wringing about the deleterious effects of ‘screen time.’ But the […]