Have Smartphones Destroyed a Generation?

More comfortable online than out partying, post-Millennials are safer, physically, than adolescents have ever been. But they're verging on a mental-health crisis, writes Jean M. Twenge in an adaptation from her book "iGen." Quote: "The more time teens spend looking at screens, the more likely they are to report symptoms of depression." And: "The shift is stunning: 12th-graders in 2015 were going out less often than eighth-graders did as recently as 2009."