Cross-referencing prevalence of smoking on TV across the past 60 years with trends in cigarette consumption, researchers investigate whether televised depictions of smoking influence our own habits.
In 1970, Richard Nixon signed legislation officially banning the advertisement of cigarettes on TV. Smoking in televised drama, though, has not been banned - although depictions of tobacco use on TV and in films has variously fallen and risen over the years.
Previous studies, for instance, have suggested that from the 1950s to the early 1980s the portrayal of smoking dwindled, only to rise again between 1981 and 1993.
TV viewing habits have also changed over the decades. In 1955, 65% of households in the US had a TV set, but within 10 years this had grown to 93%. In 1955, Americans watched around 4 hours and 51 minutes of TV a day, but by 2006, this had almost doubled to 8 hours and 14 minutes per day.
So exposure to televised smoking could have increased due to people watching more TV, even though the amount of smoking in TV programs and movies may have declined.
The relationship between depictions of smoking and real-life smoking behaviors is of interest to researchers because previous research has found that, when adult smokers watch a movie with smoking scenes, they experience cravings for cigarettes. And some researchers believe that dramatized tobacco use can influence whether adolescent viewers take up the habit.
The researchers behind the new study, which is published in Tobacco Control, watched 1,838 hours of popular prime-time dramas that were broadcast between 1955 and 2010. They coded them to show how much airtime depicted protagonists smoking, or buying or handling tobacco.
The study shows that these "tobacco events" on TV have fallen from 4.96 instances per hour of programming in 1961 to 0.29 instances per hour in 2010. This is in line with a decline in cigarette consumption over the same period.
Which is the bigger influence on consumption - televised smoking or tobacco price?
Factors such as the price of tobacco also influence the popularity of smoking. The researchers compared the price changes in tobacco over the study period with the number of tobacco events on TV and the prevalence of smoking.
The researchers estimated that the visibility of tobacco on TV had about half the impact on the declining rates of smoking as the price of tobacco did.
From their results, the researchers estimated that the visibility of tobacco on TV had about half the impact on the declining rates of smoking as the price of tobacco did.
They calculated that, for every one less tobacco event per hour of programming across 2 years, there would be two fewer packs of cigarettes smoked for every American adult.
As well as tobacco events in drama, the researchers also imported some data into their study from other research that suggested a correlation between the number of stories on TV news about tobacco and adult smoking prevalence.
But the study did not take into account whether the depictions of tobacco use in the programming they coded were positive or negative - for instance, whether it was mainly "heroes" or "villains" in drama who smoked - so the researchers cannot account for whether the nature of the depiction influenced tobacco use.
The team believes that more smoking-related deaths could be further avoided if there were less tobacco-related events on TV. They also argue that smoking depiction in other media, such as YouTube, should be included in further studies examining this link.
In other smoking-related news, Medical News Today recently reported on a study suggesting that smokers' taste buds do not allow them to taste the bitterness of coffee.