According to the study, which was published in January's Pediatrics journal, 10 percent of participants began smoking during the course of the research. Of these participants, 35 percent were triggered to do so by exposure to smoking in movies. Eighty percent of this exposure came from movies with G, PG or PG-13 ratings.
"We didn't expect to find what we did,"said Linda Titus-Ernstoff, DMS professor of community and family medicine, who authored the study. "At first I didn't believe the results."
The study, led by DMS professor of pediatrics Madeline A. Dalton, tracked 2,255 students between ages nine and 12 from 26 elementary schools in Vermont and New Hampshire over a 101-week period. The study was notable for its examination of elementary school children and its consideration of whether or not students began smoking during the course of the study -- angles which have not been included in previous studies of this type.
The study was unable to determine if participants who tried smoking became habitual smokers. This question will be the subject of Dalton's next study, according to Titus-Ernstoff.
Titus-Ernstoff said she found the prevalence of smoking in movies rated for children alarming because it frustrated attempts of parents who try to shield their children from content, including smoking, generally associated with R-ratings.
Researchers also discovered that exposure to smoking in movies had significant long-term effects. Movies the students viewed up to five years prior to the study had an equally strong impact on the decision to smoke as movies viewed only months before the study began.
"Parents need to keep an eye on this from a very young age," Titus-Ernstoff said. "It seems to have an effect even before parents think their kids understand what they're seeing."
The study consisted of an initial survey that students filled out at school, a preliminary phone conversation and two follow-up phone calls one and two years later. Students who indicated they had already tried smoking in the initial survey were excluded from the study.
In the survey, participants indicated which movies they had seen from a list of 50 films chosen randomly from the 550 top-rated movies in the past five and half years.
In each of the two following phone conversations, researchers asked students if they had tried smoking and determined which of 50 movies students had seen, randomly generated from an updated list of the year's top 200 films.
Researchers determined students' exposure to smoking by calculating the amount of time cigarettes were shown in each of the movies.
Researchers took race, sex, school performance and the presence of friends or parents who smoked into consideration when judging results.
Titus-Ernstoff said she hopes the study inspires tighter regulation on smoking in children's movies.
"This is what advertising is about: messages through images," Titus-Ernstoff said, "It's extremely effective to advertise, and the tobacco industry knows that."
Titus-Ernstoff said the study made her feel lucky.
"I let my kids watch pretty much anything and none smoke. Of course I'd kill them if they did," she said.
