Katherine Schaeffer writes: “The photo and video sharing platform Instagram has become especially popular among young adults and teens. The site—a home for online influencers, political and election news, and disinformation campaigns—has come under scrutiny after recently leaked research concluded that parent company Facebook knew the use of the site can have negative mental health effects for teenagers, especially teen girls. Over the years, Pew Research Center has studied how US adults—as well as teens and children—use and engage with the platform. Here are seven key takeaways from our research.”