In a disturbing new study, nearly one in 10 of the 14- to 21-year-olds surveyed reported coercing or forcing an unwilling partner into a sexual act, researchers found.

In the study, published Monday in the journal JAMA Pediatrics, surveyed 1,058 people ages 14 to 21 and found that 9 percent admitted to having perpetrated an act of sexual violence - a broad term that refers to acts ranging from sexual harassment to rape. The study was done online via a survey during 2010 and 2011.

Out of those that admitted to forcing a sexual act, four percent said they attempted or successfully forced someone to have sex against their will. Another eight percent reported kissing or touching someone when the person didn't want them to and three percent said they had coerced someone into having sex.

More than one million people are victims of sexual violence in the U.S. each year, wrote Michele L. Ybarra, MPH, PhD, of the Center for Innovative Public Health Research in San Clemente, Calif., and Kimberly J. Mitchell, PhD, of the University of New Hampshire in Durham, N.H. In terms of race, Latino and African American youths, and those from low-income families, were less likely to have coerced another person to engage in sex than were whites and those from higher-income families, the study found.

In 73 percent of the reported cases in the study, the victims said they were romantic partners while 50 percent of perpetrators said the victim was responsible for the sexual violence. Since most of the cases were among teenagers in a relationship, the victim felt uncomfortable reporting the case to the police.

"Sexual violence can be perpetrated by anybody - a dating partner, a friend or somebody you don't know," says Michele Ybarra. "We asked perpetrators about their relationship with their most recent victims, and one in four said it was not a dating partner."

The study found the most common age when the first perpetration of sexual violence occurs is  16 years old, and males were overwhelmingly more likely to have their first episode at 15 years of age or younger. By the time they were 18 and 19, however, males and females were equally likely to commit sexual violence.

The study only scratches the surface and further research needs to be done to better understand this behavior.

Meanwhile, the study found perpetrators of sexual violence also tended to report more frequently being exposed to media that depicted sexual and violent situations, although the results were not always statistically significant.