The takeaway for teens, said lead researcher Sarah Coyne, is this: "I would hope kids would let their parents 'friend' them. It's going to strengthen the relationship."
Past research has shown the value of parents and children playing video games or keeping in touch by cellphone, said Coyne, who teaches in the BYU School of Family Life, as does co-author Laura Padilla-Walker.
"This is one more type of media parents can use to connect with their kids," Coyne said. "It's a tool in the tool kit."
The research involved 491 families in the Seattle area, which BYU researchers have been following and interviewing on a variety of topics for seven years. Only about half the families communicate with one another via social media, she said.
Researchers found that more interaction is better than less, although few only 16 percent communicate via the websites every day.
Parents can show affection and give positive feedback, but they can also learn more about their teens' interests and friends. "It provides a nice little window," Coyne said.
The research doesn't give a prescription for what works and what doesn't. It takes no position on whether posting a 16-year-old's baby picture is a good idea.
But, Coyne said, "You [shouldn't] be over-intrusive. You have to respect your teen's privacy." She also cautioned that interacting via social media is no cure-all. "If you have an awful relationship, friending on Facebook is probably not going to fix it."
One interesting finding, Coyne said, is that teens who spend too many hours on social media are more depressed and aggressive.