Facebook has recently paused the development of their “Instagram Kids” project after a whistleblower leaked internal documents showing that Facebook's own research finds a link between poor mental health and Instagram use. “We make body image issues worse for one in three teen girls,” said a slide in a presentation given to Facebook executives, “Teens blame Instagram for increases in the rate of anxiety and depression,” said another. Not surprisingly, the Wall Street Journal’s expose has led to a bipartisan backlash against Facebook, with law-makers, child advocates, psychologists, and users themselves describing the harmful effects of social media as the “public health issue of our time.”

For years psychologists have been warning the public that social media, and Instagram in particular, were contributing to large increases in depression and anxiety in teenagers, especially girls. Jean Twenge, psychology professor at San Diego State University whose research looks at generational trends found in very large data sets, described in her 2017 book, iGen, sharp decreases in behaviours that prepare young people for adulthood such as driving, dating, socialising at parties, and working.

These trends have occurred in parallel with sharp increases in anxiety and depression, and general feelings of loneliness for this cohort. Twenge’s hypothesis in 2017 was that these trendlines corresponded with widespread changes in behaviour driven by smartphones, as well as the ubiquitous adoption of social media by teens. No other plausible hypothesis for these trends has emerged, and since 2017, they have become more pronounced. Now Facebook’s own research appears to confirm Twenge's hypothesis.