I BLAME SOCIAL MEDIA: Jonathan Haidt: The Teen Mental Illness Epidemic is International, Part 1: The Anglosphere. “It is now widely accepted that an epidemic of mental illness began among American teens in the early 2010s. What caused it? Many commentators point to events in the USA around that time, such as a particularly horrific school shooting in 2012. But if the epidemic started in many nations at the same time, then such country-specific theories would not work. We’d need to find a global event or trend, and the 2008 Global Financial Crisis doesn’t match the timing at all, as Jean Twenge and I have shown.”

Plus: “At this point, there is only one theory we know of that can explain why the same thing happened to girls in so many countries at the same time: the rapid global movement from flip phones (where you can’t do social media) to smartphones and the phone-based childhood. The first smartphone with a front-facing camera (the iPhone 4) came out in 2010, just as teens were trading in their flip phones for smartphones in large numbers. (Few teens owned an iPhone in its first few years). Facebook bought Instagram in 2012, which gave the platform a huge boost in publicity and users. So 2012 was the first year that very large numbers of girls in the developed world were spending hours each day posting photos of themselves and scrolling through hundreds of carefully edited photos of other girls.”