Millennials check their phones 150 times a day, more than 2 billion people use Facebook, and another 2 billion use YouTube. What’s the root of our digital addiction? Tristan Harris, former Google ethicist and founder of the Center for Humane Technology, says these companies have perfected the use of persuasive technology and we’ve fallen for it. It’s a problem, says Harris, because technology has the power to modify people’s behavior, attitudes and beliefs. He tells author and journalist Charles Duhigg that persuasive technology is partly to blame for political polarization, election manipulation, and loneliness. Duhigg is the author of “The Power of Habit.”