Jonathan Haidt's book The Anxious Generation made a big splash in education circles last year. It elaborates the thesis that social media is harming people's mental health, especially that of teenagers and young adults. Haidt has compiled a lot of different evidence that he says supports this conclusion, but some of his academic colleagues aren't buying it. To briefly summarize Haidt’s position, there is strong correlational evidence based on two co-occurring trends: The specific timeframe from 2010-2015 showed a dramatic emergency of new mental health problems on a wide range of measures for teenagers, especially younger adolescents ages 10-14. At the same time, smartphones made social media apps continuously available to people in this age bracket. Haidt argues that it was the specific combination of social media apps and the internet in one’s pocket that made the situation so harmful, which helps him to explain why this specific 5-year peri...