Two years ago, social psychologist Jonathan Haidt released his New York Times bestseller The Anxious Generation. The book posits that the rise of social media and smartphone use is largely to blame for the prominent decline in teen mental health since 2010. It quickly became a central rallying cry of the social media backlash. Haidt has been credited with helping inspire Australia's nationwide teen social media ban. He has joined forces with bereaved parents who are fighting tech companies in court. His name comes up unprompted in conversations with people in power who say his book opened their eyes to an online crisis.
Haidt's theory has …