For years, the research picture on how social media affects teen mental health has been murky. ""Now, in the most recent data, 22% of 10th grade girls spend seven or more hours a day on social media," Twenge says, which means many teenage girls are doing little else than sleeping, going to school and engaging with social media. Social media for children is a bit like the ocean, she says, noting that it can be an extremely dangerous place for children