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July 20, 2007 -
One of the “nice”
things about the advocacy of the anti-tobacco lobby is how consistently silly,
not to say nonsensical, its claims are. Unencumbered with the responsibilities
of reputable research and rigorous analysis of whether their purported solutions
really work, the anti-tobacco zealots are able to continue on year after year
re-cycling to a lazy media their same sound-bite claims as the novel product of
serious thinking on the hard problem of preventing smoking.
Take, for
instance, the increasing media attention- generated entirely by the anti-tobacco
movement- to the claim that smoking in films is a, some would say the central
“cause” of youth smoking. For example, activist Stanton Glantz has claimed that
seeing onscreen smoking is the main reason why teens begin to smoke. Indeed,
Glantz even has precise figures, arguing that “smoking in movies is responsible
for addicting 1080 US adolescents to tobacco every day… (Lancet, 2003). And
Glantz is not alone. The just released report by the US Institute of Medicine
Ending the Tobacco Problem: A Blueprint For The Nation (which will be the
subject of next month’s column) wades into the smoking in films controversy by
claiming not only that “exposure to smoking in movies increases the risk for
smoking initiation” (6-42), but that this increased risk “can be reduced by
antismoking advertisements….”(6-42) The report recommends that the Motion
Picture Association should consider tobacco use in films as a factor in
assigning a film an R-rating.
Additionally a new
study-actually merely a meta-analysis of previous studies- by University of
Massachusetts researcher Robert Wellman has been widely reported as providing
evidence of a “causal link” between smoking in films and becoming a smoker. And
these stories have been accompanied by reports that the Motion Picture
Association of America will include smoking in films, along with language, sex,
violence and drug use, as part of the criteria for movie ratings. This, of
course, falls considerably short of what activist groups wants. Some like the
Smokefree Movies Action Network want smoking completely eliminated from films,
while others want merely a R rating for any film with smoking.
While
India
has heeded these calls to eliminate onscreen smoking, Australia has taken the
different and controversial approach of following the IOM’s “research-backed”
advice by screening 30 second anti-smoking ads shot in movie trailer style
before films which contain scenes with smoking. The ads show actors smoking and
warn viewers not to be sucked in by the “tobacco giants” who “crave fresh
blood”.
Unfortunately the
ads have not had quite the effect that was intended. A just published study in
Tobacco Control (June, 2007) by Christine Edwards and others examining the
Australian approach found that the advertisements did not produce reduced
intentions to smoke. For instance, 25% of smokers who had not seen the ads
before films with smoking said that they would still be smoking in a year’s time
compared to a striking 39% of smokers who had seen the supposed anti-smoking
ads. And the ads had no statistically significant effect on the smoking
intentions of nonsmokers. All of which suggests that the pre-smoking film ads
are like so many anti-tobacco initiatives counterproductive as well as
contradicting the supposedly evidence-based claims of the Institute of Medicine
that such ads reduce the effects of youth viewing of smoking in the movies.
But the problems
with the claims about the effects of young people seeing smoking depicted in
films go far beyond the failure of anti-smoking advertisements preceding films
to have any effect on smoking intentions. Indeed, they extend to the much more
important claim about whether there is indeed a causal connection between
adolescents seeing people smoke in films and starting to smoke themselves. In
fact, what the evidence about the ineffectiveness of pre-film anti-smoking
advertisements should do is to cast doubt on the entire hypothesis that seeing
smoking in films is a cause of youth smoking.
There are three
reasons to doubt that films that show smoking cause youths to smoke. To begin
with, the research- at least ten major articles during the last five years-
which purports to show this causal connection is deeply flawed. Take, for
example, the just published analysis by Wellman et al “The Extent to Which
Tobacco Marketing and Tobacco Use in Films Contribute to Children’s Use of
Tobacco” (December 2006, Archives of Pediatric and Adolescent Medicine)
According to Wellman, films which depict smoking create positive views about
smoking and these positive views lead to an increased intention to start
smoking. To support this claim, Wellman analyzes 51 studies with 89 exposure
measures. But of these 89 measures of exposure, only 10 were about exposure to
smoking in films- a very slender base on which to claim that such exposure
causes adolescent smoking. Further, though Wellman cites crucial studies about
the huge number of things that influence adolescents to begin smoking, some
studies suggest over 200 different risk factors, he notes that the studies he
uses in his meta-analysis fail to take account of these other risk factors for
smoking. Yet without taking account of these it is impossible to determine what
influence, if any, smoking in films might have. Most crucially, he fails to note
several studies which have consistently found that young movie viewers do not
rate smoking characters as particularly attractive. This undermines his central
thesis that depictions of smoking create a positive view about smoking. It seems
rather a stretch to conclude that adolescents are driven to smoke by smoking
characters whom they do no like.
Nor is the
questionable quality of the Wellman research unique. An often cited study by
Madeline Dalton (The Lancet 2003 “Effect of viewing smoking in movies on
adolescent smoking initiation: a cohort study”) which claims to establish a
causal connection between smoking in films and youth smoking, for instance, did
not even ask its subjects whether they found a film’s portrayal of smoking to be
positive- which is surely the relevant research question given the assumption
that such a positive attitude is the cause of beginning to smoke. Instead,
Dalton assumes that because her subjects starting smoking after seeing someone
smoking in a film that they must have started smoking because they saw someone
smoking in a film.
Dalton
then typifies the second reason why the claim that seeing smoking in films leads
youth to smoke cannot be trusted, namely it is based on epidemiological studies
that cannot by their nature ever establish such causal claims. Such studies are
always merely associational. Dalton and Wellman claim to skirt this limitation
through prospective studies in which nonsmokers are studied. Both tell us-
apparently with a straight face- that because the kids they studied only started
smoking or at least experimenting with smoking AFTER they saw movies with people
smoking, then we can be certain that they started smoking because they saw
movies with people smoking.
This, however, is
both confused and dishonest. Sequence is not consequence as anyone who has ever
studied logic will remember. Post hoc ergo propter hoc-after this therefore
because of this- is still a fallacy, even in anti-tobacco land. Just because
something follows something else- in this case starting to smoke follows seeing
movies with smoking scenes, it is not true that the one is the cause of the
other. The fact that two things happen simultaneously over the same time period-
adolescents begin to smoke and adolescents begin to go to R-rated films with
smoking, does not mean that the one fact is the causal precipitator of the
other.
The students in
the Dalton
study came into contact with dozens of risk factors for starting to smoke during
the time that they were seeing films with smoking. How is it that Dalton knows
that it was seeing films with smoking scenes that was the cause of their
smoking? What these sorts of studies reduce to is the claim that X- in this case
youth smoking- might be caused by A, B, C, D, E, F, or G, of which we have only
looked at A but we still believe that A is the cause of X. The serious research
literature on the causes of youth smoking has discovered dozens of risk factors.
Wellman even acknowledges that there are a variety of “psychosocial factors”
which increase the odds of starting to smoke. Yet Dalton controls for only a
handful of these even while claiming that viewing on average 17 films in which
there is smoking leads young people to begin smoking.
But here is an
equally plausible interpretation of these and similar results. Since smoking
scenes occur most often in R rated films, it could be that young people who view
such films are more likely to become smokers, regardless of the content of the
films. There is an association between R- rated films and smoking but it is not
a causal one. The things which the smokers have in common is their attraction to
R-rated films, not to the smoking scenes in R-rated films. In other words,
potential youth smokers share a number of characteristics such as liking R-rated
films, but this does not mean that R- rated films with smoking scenes lead to
youth smoking. Alternatively, other risk factors for smoking than smoking scenes
might be found in R-rated films. This possibility is in fact acknowledged by
Sargent et al in their study on smoking in films and youth uptake, but dismissed
on the odd grounds that their explanation is more “theoretically reasonable.” So
indeed was the belief that the sun revolved around the earth. Unfortunately, the
science suggested otherwise, as it does here.
But there is a
third reason why such claims about films with smoking leading to smoking
initiation cannot be trusted and that is that there is a very substantial mass
of research which not only points in different directions but contradicts these
claims. For one thing there are dozens if not hundreds of studies which find
that the strongest predictors of youth smoking initiation are personality
variables such as rebelliousness, socioeconomic factors such as family income,
school-related factors such as academic success and remaining in school and such
coping skills as resilience. These make nonsense of the Glantz claim that seeing
onscreen smoking is the “main” reason why teens begin to smoke.
For another thing
the research about the supposed effect of smoking in films on youth smoking
itself contradicts the claim that seeing smoking lead to smoking. The just
published study from Australia about the ineffectiveness of showing anti-smoking
ads prior to films with smoking notes that the young people’s views about
smoking were linked to their current smoking status, age and gender but “not to
the movie viewed.”(Edwards et al Tobacco Control, 2007) In other words the
smoking scenes in the films these young people viewed were NOT responsible for
their beliefs about smoking. The same study also found that the young people’s
intention to smoke during the next year was related to their current smoking
status, age and gender and NOT to the content of the movie- complete with
smoking scenes- that they had seen. So the very sort of quasi-experimental study
that is so praised by anti-tobacco activists actually refutes their core claim
that smoking scenes lead young people to start smoking.
Finally, there is
the odd claim that even if the evidence for a causal connection between seeing
smoking in films and starting to smoke is weak, we know it is true because there
is a causal relationship between violent media such as video games and “violent
attitudes and behaviors in children and adolescents” which “makes it plausible
that tobacco marketing and media also affect behavior.” (Wellman, p. 1293) Aside
from the fact that only one study is listed as support for this sweeping
conclusion about video games and violence, and that virtually all of the
research is correlational and hence cannot establish causal connections, there
is little evidence supporting such links between video games and violent
behaviour according to the Federal Trade Commission’s review of the issue.
Youth smoking has
suffered from over 25 years of bad research and simplistic policy prescriptions
from the anti-tobacco movement. Despite the fact that the evidence is not
supportive- there is no causal connection between tobacco advertising bans and
reduced youth smoking, for instance, the anti-tobacco activists have always
claimed that advertising is the major cause of young people starting to smoke.
Now with tobacco advertising increasingly banned and young people still smoking,
the claim is that it is seeing smoking in films that is the major cause of young
people beginning to smoke. But the evidence for this is just as contrived and
flimsy as it was for the claims about tobacco advertising. Neither removing
smoking from films or young people from cinemas that show films with smoking
will do anything to solve the problem of youth smoking. But it will sidetrack
attention from the consideration of policies that might.
John Luik |
