most notably teenage girls

Researchers inside Instagram, which is owned by Facebook, have been studying for years how its photo-sharing app affects millions of young users. Repeatedly, the company found that Instagram is harmful for a sizable percentage of them, most notably teenage girls, more so than other social-media platforms. In public, Facebook has consistently played down the app’s negative effects, including in comments to Congress, and hasn’t made its research public or available to academics or lawmakers who have asked for it. In response, Facebook says the negative effects aren’t widespread, that the mental-health research is valuable and that some of the harmful aspects aren’t easy to address.