In the past, we thought of addiction as mostly related to chemical substances: heroin, cocaine, nicotine. Today, we have this phenomenon of behavioral addictions where, one tech industry leader told me, people are spending nearly three hours a day tethered to their cellphones. Where teenage boys sometimes spend weeks alone in their rooms playing video games. Where Snapchat will boast that its youthful users open their app more than 18 times a day.