Many aspects of San Francisco life could arguably benefit from warning labels, including the dangers of driving up the city’s steep hills, and the shock that can result from perusing its real estate ads. But public officials in the beautiful City by the Bay are going in a different direction.
Pending final approval by the mayor and board of supervisors, San Francisco is set to approve an ordinance stating that all ads for sugary soft drinks on billboards, buses, and other public spaces must carry a warning label noting that such beverages contribute to obesity, diabetes, and tooth decay.
There is plenty of science backing up that assertion. But will such ads be effective? If the goal is to make these sweet drinks less appealing to children or adolescents, recent research from Germany suggests it’s unlikely.
Especially for younger teenagers, such warnings are effectively negated when marketers "enhance the advertisement with pictorials—which is usually the case," writes a research team led by the University of Hamburg's Tobias Effertz. Enticing imagery, the researchers write, not only helps sell products: It also significantly dilutes the impact of a warning label.
"Younger children seem to depreciate the warning information if a pictorial is simultaneously presented."
In the June 2014 issue of the Journal of Consumer Policy, Effertz and his colleagues describe a study featuring 404 German adolescents between the ages of 10 and 22. "Four different types of advertisements were generated and compared across respondents," they write, "with (1) pictorial or purely informative content, and (2) with or without a warning claim."
One ad simply featured an image of the drink carton, the name of the product, and a simple slogan. The other featured the carton and product name, set against the background of a tropical beach scene featuring sand and palm trees.
Alternative versions of both ads were prepared, in which a large exclamation point and the warning "Contains three times as much sugar and caffeine as regular soft drinks" was placed directly underneath the main image. After examining one of the ads, participants indicated how interested they were in trying the drink.
"In general, warnings negatively affect purchase intention," the researchers report. However, they add, "this effect is diluted when the warning is embedded in an advertisement with pictorial framing."
This proved especially true for the youngest kids in their study. "Younger children seem to depreciate the warning information if a pictorial is simultaneously presented," the researchers write. "In the extreme case of children below 12 years, adding a warning to a visual advertisement even increased purchase intentions."
Older kids were less likely to be distracted by the attractive visuals, but only to a point. "For elder adolescents, warning labels might be understood correctly," the researchers write. "However, they still compete against other advertising elements."
So even for kids in their late teens or early 20s, "the negative effects of warnings on purchase intention are offset by countervailing effects of pictorials. This effect diminishes with age, but remains present."
In other words, the warning labels effectively set up a battle between words and images. And in this study, at least, images were powerful enough to counter-balance the effect of the warnings.
So unless the city of San Francisco mandates simple ads stripped of enticing images—a law that would presumably run into First Amendment problems—its attempt to get young people to think twice about drinking sweet carbonated sodas may very well fall flat.
Findings is a daily column by Pacific Standard staff writer Tom Jacobs, who scours the psychological-research journals to discover new insights into human behavior, ranging from the origins of our political beliefs to the cultivation of creativity.