Teenagers are turning away from Facebook because of friends who overshare information and concerns about their parents knowing what they are up to.
Teens told researchers there were too many adults on Facebook and too much sharing of teenage angst and inane details like what a friend ate for dinner.
Instead, they are turning to Twitter and Tumblr in increasing numbers - where they are sharing more personal information about themselves than ever before.
"The key is that there are fewer adults, fewer parents and just simply less complexity and less drama," said Amanda Lenhart of the U.S.-based Pew Research Center, one of the study's authors.
"They still have their Facebook profiles, but they spend less time on them and move to places like Twitter, Instagram and Tumblr."
In the poll, 94 per cent of teenagers who are social media users have a profile on Facebook - flat from the previous year.
Of potential concern to parents, more than 60 per cent of the teens with Twitter accounts said their tweets were public, meaning anyone on Twitter - friend, foe or stranger - can see what they write and publish.
About one-quarter of kids said their tweets were private and 12 per cent said they did not know whether their tweets were public or private.
"Teens are sharing more information about themselves on social media sites than they did in the past," the researchers warned.