Children ages 10 to 14 who view many movies with characters who smoke are more likely to try cigarettes themselves, a new study suggests.

Onscreen smoking influences children regardless of the film’s ratings, Reuters reports. This suggests that it is the smoking itself, rather than the sex, violence or profanity that may accompany it, that persuades them to try cigarettes, the study authors say.

“Movie smoking seems to be just as impactful if it’s packaged in a PG-13 movie as opposed to an R movie,” said lead author Dr. James Sargent of the Geisel School of Medicine at Dartmouth in Lebanon, New Hampshire. “I really think it’s a ‘cool’ factor. The more they see it, the more they start to see ways that (smoking) might make them seem more movie-star.”

The researchers counted how many times characters were seen smoking, in each of more than 500 popular movies. They then asked 6,500 10- to 14-year-olds which of the movies they had seen. The children were re-interviewed during the following two years. Those who had seen movies with a lot of smoking were more likely to start smoking themselves, the study found. For each additional 500 scenes of smoking they had seen, the children were 33 to 49 percent more likely to try smoking themselves over the next two years.

Sargent recommends that children watch no more than two movies a week. He says they should not watch R-rated movies until they are “well into adolescence.” The study appears in the journal Pediatrics.

In a study published earlier this year, Sargent found that watching movies with scenes that feature alcohol consumption doubles the likelihood that teens will start drinking alcohol. The study also found that teens who are exposed to alcohol-fueled movies are more likely to progress to binge drinking (five or more drinks in a row).