Updated

If you thought PG-13 movies were less violent than R-rated flicks, think again. More gun violence plays out on the big screen in movies open to all ages than in R-rated box office blockbusters, reports FastCo.Exist.

Researchers found that gun violence in PG-13 action movies is on the rise with Hollywood increasingly relying on shoot-'em-up scenes to fill seats. Building on an earlier study, they sampled 30 top-grossing films between 2012 and 2015 to determine the number of five-minute segments in which a character fires a gun at someone. Writing in the journal Pediatrics, they report the rate of gun violence in PG-13 movies in 2012 equaled that of R-rated films, restricted to 17 and older, and outpaced those films in later years.

Kids of all ages are allowed into cinemas showing PG-13 movies, though parents are "strongly cautioned."

Some of the most violent PG-13 films were some of the most popular, like 2015's "Star Wars: the Force Awakens." (See the full list here.)

Also of note: The authors say films often remove the consequences of gunplay. Thus, children and their parents are being "desensitized" to these effects, they contend, comparing on-screen bloodshed to behaviors like smoking and drinking that can young people often imitate. Previous research has shown that repeated exposure to violence on screen can make kids more aggressive.

"We know less about the potential effects of films that glorify the use of guns," the authors write. Until more is known, they say, pediatricians should advise parents "to be cautious about exposing their children" to violent films. (In related news, violent superheroes can make kids more aggressive.)