Every parent knows that self-control is an important skill. We spend hours talking about it with our kids, sometimes to no avail. Self-control is hard, even for adults—it’s always a “no,” or a state ...

We all want to master self-control. To say no to distractions, to break bad habits, and to stay focused on what truly matters. Yet, how many times have you felt like your willpower just isn’t enough?

Nearly half of teenagers report being online nearly constantly, according to a recent survey by the Pew Research Center. And “screen-time” is pervasive among younger children, surveys show. There’s no ...