More than half of teens on MySpace discuss or post images on their profiles of sex, drugs and violence, new research shows. But another study finds that reminding kids the info is public may tame the content they publish on the social-networking site.

Some 270 (54 percent) of 500 MySpace profiles referenced risky behavior, according to the first study in today's Archives of Pediatrics & Adolescent Medicine. Of those, 24 percent mentioned sex, 41 percent drugs and 14 percent violence. The findings are based on reviews by researchers at the University of Washington in Seattle and the University of Notre Dame of profiles whose users said they were 18.

The researchers acknowledge that there's no way of verifying the ages or information of the users. But they note that social-networking sites have been used by cyber-bullies and online predators to target unwitting users. And whether or not the profiles reflect the truth, other teens will take the online information literally, magnifying the peer pressure that already exists in real life, says co-author Megan Moreno, now an assistant professor of pediatrics at the University of Wisconsin–Madison.

"Maybe they haven’t drunk alcohol yet, but they put up pictures that look like they are and see if it is acceptable or not," Moreno says. "They're boasting. Or it's nonsense. But the potential for danger is the same, regardless of the reason they put it up in the first place, because teens in general interpret other teens' disclosures as being real life.

"We know how powerful peer pressure is in real life," Moreno adds. "They're probably going to feel pressure to engage in behaviors they might not otherwise have done."

In a second study published in the Archives, Moreno identified 190 MySpace users from an impoverished U.S. city (she wouldn’t say which one) who alluded to drugs and sex in their profiles, then sent an e-mail to half of them, noting that "you seemed to be quite open about sexual issues or other behaviors such as drinking and smoking. Are you sure that's a good idea? … You might consider revising your page to better protect your privacy."

When Moreno checked the profiles three months later, references to sex decreased by13 percent among kids who had received the e-mail, compared to a drop of 5 percent among those who hadn't received it. The drug and alcohol references fell by 26 percent among e-mail recipients, versus a decrease of 22 percent among non-recipients. In addition, 10 percent of those who received the e-mail had changed their security settings from public to private, versus 7 percent who didn’t get the e-mail.

This isn’t the first time MySpace has been used to educate kids about health; the New York City Department of Health and Mental Hygiene last summer set up a profile that users could "friend" that chronicles composite characters' experience with depression and offers resources that can help. Moreno's more direct approach may rankle privacy advocates, but she defends sending it. Online privacy advocates, she says, "are doctors and parents and teachers, and these are the people who should not be worrying about privacy. The people who have no business looking [at kids' profiles] are the ones looking.

"If I had a patient who came in in a shirt that said, 'I like to have sex,' I'd feel OK to comment on it; it’s a public message they're sending," Moreno adds. "A MySpace profile is not that far from being a personal bulletin board."

MySpace declined to comment on the studies. MySpace, the most popular social-networking site on the Web with 200 million users (a quarter of them minors), automatically keeps private the profiles of users under 18. Those who say they're 16 or 17 can change the settings to public once they set up a profile, but profiles of those who say they're 13 to 15 are kept private.

Image by iStockphoto/U.P. images