Sexting, the sending or receiving of sexually explicit text messages or photos via cell phone, appears to be part of a cluster of risky sexual behaviors among adolescents, rather than a substitute for "real world" sex, according to a USC study in the October 2012 issue of Pediatrics.

Teens who said they had sexted were more likely to report being sexually active, and were more likely to have had unprotected sex during their most recent sexual encounter, compared with those who did not sext, according to the study, "Sexually Explicit Cell Phone Messaging Associated With Sexual Risk Among Adolescents."

The study dealt with the health implications of sexting. Although only 15 percent self-report sexting, lead author Eric Rice of USC noted that half believe that their peers are already doing it.

"Teens live in a world where sexting seems like a normal behavior and not just among their friends," said Rice, an assistant professor in the USC School of Social Work. "They hear about politicians and celebrities in the news doing it, too. Imagine how vulnerable teens are to this behavior when it seems like adults do this all the time. We've never had to deal with these kinds of consequences.

"But they are real even if they start off digital. Teens need help navigating this technology even though they seem so expert."

The study, published online Sept. 17, examined data from more than 1,800 Los Angeles high school students.

Of those teens with access to a cellphone, 15 percent reported that they had engaged in sexting, and 54 percent of students said they knew someone who had sent a sext.

"The data reveal that sexting is associated with sexual risk taking, activity and often unsafe sex, such as not using a condom," Rice said.

African American and lesbian/gay/bisexual/transgender participants were more likely to report having sexted, which is alarming because these populations are already at increased risk for the transmission of HIV and STDs, the study reported.

The study also suggests that sexting and the behaviors associated with it be added to school-based health class curricula.

Rice suggests the topic of sexting can be a low pressure way of engaging teens in conversation about sex, sexually transmitted disease and birth control.

"Sexting may be another means for adolescents to explore their sexuality, engage in sexual experimentation, and determine their moral and sexual values," Rice said.

Harmony Rhoades and Hailey Winetrobe of the USC School of Social Work, Monica Sanchez of Clark University, Jorge Montoya and Aaron Plant of Sentient Research, and Timothy Kordic of the Los Angeles Unified School District were co-authors of the study.