A study in Pediatrics has found violence in films has more than doubled since 1950, and the presence of gun violence in PG-13-rated films has more than tripled since the rating was introduced in 1985. The study, “Gun Violence Trends in Movies,” in the December 2013 Pediatrics (published online Nov. 11), analyzed a sample of the top-grossing films for each of the years from 1950 to 2012. Trained analysts coded each film for the presence of violence and guns during each 5-minute segment of the movie. Researchers found an overall annual increase in gun violence from 1985 to 2012, but the trend differed by movie rating. Among films rated G and PG, gun violence decreased slightly. The rate of gun violence did not change for R-rated movies. Among films rated PG-13, gun violence increased, and since 2009, PG-13 movies have contained as much or more violence than R-rated movies. The study authors conclude that even if youth do not use guns, because of the increasing popularity of PG-13 movies, they are exposed to considerable gun portrayal and violence, which may increase their aggressive behavior.