corporate funding is provided by stephens inc. - jonathan haidt, welcome to "firing line." - margaret, what a pleasure. - we've known each other for several years, and i have followed your work for many years. you are out with a brand-new book, "the anxious generation: "how the great rewiring of childhood "is causing an epidemic of mental illness." what is the great rewiring? - the great rewiring refers to a five-year period, an extraordinary five-year period, where the nature of life for adolescents changed radically, more than it ever has. in 2010, adolescents had flip phones. they had no, most did not have high-speed internet. they had, did not have unlimited data plans. they did not have instagram. they did not have front facing cameras. over the next five years, by 2015, most american teens have a smartphone with a front-facing camera, high-speed internet. they have an instagram account or other social media account, snapchat, a bunch of other ones. and now in 2015, it's possible to spend almost every waking hour online, and