Ross O'Hara, currently a postdoctoral fellow at the University of Missouri and psychological scientists at Dartmouth College, found teens who watched more sexual content also began sexual activity at an earlier age than others.
"We can't say that watching sexual content in movies is directly responsible for adolescents' sexual behavior," O'Hara said in a statement. "However, there is a correlation between the two. Sensation seeking, or the tendency to seek more novel and intense sexual stimulation, does seem to increase in young people who watched more movies with sexually explicit content."
O'Hara and his colleagues recruited 1,228 participants ages 12-14 years. Each participant reported which movies they had seen, choosing from randomly selected lists of 50 top-grossing films from 1998 to 2004. The movies had been evaluated for the amount of sexual content they contained.
Six years later, the participants were surveyed to find out how old they were when they became sexually active and how risky their sexual behavior might have been.
The study, published in Psychological Science, found adolescents exposed to more sexual content in movies start having sex at younger ages, have more sexual partners and are less likely to use condoms with casual sexual partners.