Decoding the meanings behind teens’ text messages is even trickier than you may have thought. Hidden behind the multitude of LOLs and BRBs, the TTYLs and <3s, is a message that is sure to make parents : (

Scott Frank, MD, a family physician and public-health researcher, wondered what we might learn from teenagers’ busy thumbs.

It turns out that teens who send more than 120 text messages per school day— what he calls hypertexters—are more likely to engage in a variety of risky behaviors as compared with their more moderate peers. After controlling for such factors as race, gender and household structure, these ultra-social teens are 43 percent more likely to smoke cigarettes; twice as likely to have tried alcohol; 41 percent more likely to have tried illicit drugs; and three-and-a-half times more likely to have had sex, among other unhealthy behaviors. Almost 20 percent of the teens Frank surveyed were identified as hypertexters.

He found similar results among hyper-networkers—teens who log more than three hours per school day on social networking sites like Facebook and Twitter. About 11 percent of the teens Frank studied were considered hyper-networkers.

The correlation sends a message to parents and pediatricians: Talk with your teens about their tech habits.