Gun use in PG-13 movies way up.

• Position: Entertainment

The amount of gun violence shown in PG-13 films has more than tripled since 1985, the year the rating was introduced, according to a study by Ohio State University, Columbus, and the University of Pennsylvania, Philadelphia. In fact, the most popular PG-13 movies of 2011-12 showed significantly more gun violence than R-rated movies of the same time period.

"Its shocking how gun use has skyrocketed in movies that are often marketed directly at the teen audience," says Brad Bushman, coauthor of the study and professor of communication and psychology at OSU. "You have to wonder why we are seeing this surge in gun violence in PG-13 movies when it isn't appearing in G-, PG-, and R-rated films."

Bushman indicates that the results are of concern because other research has revealed the presence of a weapons effect": people who simply see a gun, or even a picture of a gun, are more aggressive.

PG movies suggest that "some material may not be suitable for children," according to the Motion Picture Association of America, which creates the ratings. PG-13 movies carry a sterner warning: "Parents strongly cautioned. Some material may be inappropriate for children under 13." The MPAA indicates that a PG-13 movie "may go beyond the PG rating" in violence "but does not reach the restricted R category."

PG-13 movies also are the most popular among viewers--13 of the top 25 films in release during 2012 carried that rating, including seven of the top 10. "By the standards of the MPAA, PG-13 movies shouldn't have as much...