If you’re constantly wondering what has your teens glued to their phones, you’re not the only one. In recent years, everyone — from researchers and mental health professionals, to lawmakers and the U.S. Attorney General — have been trying to figure out just what is so addictive, with the ultimate goal of getting kids to put the screens away. But before t(w)eens can enter the screen-free utopia parents and caregivers dream of (or at least achieve a healthy balance!), it’s first important to understand...