July 9, 2012 -- Watching movie stars smoking on the big screen makes teens more likely to start smoking themselves, regardless of whether the movie is rated R or PG-13.
A new study suggests it's the cigarette smoking itself in movies that affects teenage smoking habits, rather than other adult behaviors that go with it.
Researchers found that on-screen smoking in movies rated R and PG-13 had a comparable impact on making teens more likely to smoke.
PG-13 movies typically depict cigarette smoking that is visually stimulating without the sexual or violent behavior associated with R-rated movie smoking. Think of blowing smoke into a glass or smoking while reading vs. a post-sexual-intercourse cigarette.
Researchers say about 60% of teens' exposure to smoking in movies comes from watching youth-rated, almost entirely PG-13 movies.
The results suggest imposing an R rating on movies that include cigarette smoking would have a big impact on curbing teenage smoking.
"An R rating for smoking could reduce smoking onset in the United States by 18%," write researcher James Sargent, MD, of Dartmouth-Hitchcock Medical Center in Lebanon, N.H., and colleagues in Pediatrics, "an effect similar to making all parents maximally authoritative in their parenting."
Earlier this year, the U.S. Surgeon General's report on tobacco and youth stated that there is a causal relationship between depictions of smoking in movies and initiation of smoking among young people.
But researchers say until now it was unclear whether or not the context in which the smoking is presented in movies affects teenage smoking behaviors.
In the study, researchers surveyed more than 6,500 youth and teens aged 10-14 every eight months over a two-year period. They were asked about which top-grossing movies they had seen in the previous year and if they had ever smoked a cigarette.
Researchers then counted the number of smoking occurrences each teen had seen based on their list of movies.
The results showed smoking was rare in movies rated G or PG and not linked to teenage smoking habits.
Researchers say the average number of exposures to smoking in movies was about three times higher from PG-13 movies than from R-rated movies, but the effect on teen smoking habits was comparable.
For example, teens exposed to the average number of smoking scenes from PG-13 movies were 49% more likely to have tried smoking. Those exposed to the average number of smoking scenes from R-rated movies were 33% more likely to have tried smoking.
"This study suggests that it is the depiction of smoking in movies, not other contextual variables, that matters for the onset of youth smoking," the researchers write.