Effective anti-tobacco ads should either scare or disgust viewers, study reveals

October 22, 2008

(PhysOrg.com) -- Anti-tobacco public service announcements have been around for decades, designed to encourage people to quit smoking or to refrain from starting. Often these ads try to encourage people to avoid smoking by scaring them with the harmful effects of tobacco use. In a new study, University of Missouri researchers examined the effects of two types of content commonly used in anti-tobacco ads – tobacco health threats that evoke fear and disturbing or disgusting images. The researchers found that ads focused on either fear or disgust increased attention and memory in viewers; however, ads that included both fear and disgust decreased viewers' attention and memory.

"When fear and disgust are combined in a single television ad, the ad might become too noxious for the viewer," said Glenn Leshner, lead author of the study and co-director of the Psychological Research on Information and Media Effects (PRIME) Lab in the Missouri School of Journalism. "We noticed several ads in our collection of anti-tobacco public service announcements that contained very disturbing images, such as cholesterol being squeezed from a human artery, a diseased lung, or a cancer-riddled tongue. Presumably, these messages are designed to scare people so that they don't smoke. It appears that this strategy may backfire."

There is limited understanding of the cognitive and emotional processes associated with the effects of advertising messages, according to Paul Bolls, co-author of the study and co-director of the PRIME Lab. Bolls said the purpose of the study was to examine key characteristics of anti-tobacco ads that influence viewers' cognitive processes engaged during message exposure, which potentially contribute to the messages' effectiveness.

"This study provides important insight into how young adults process anti-smoking messages, and it offers practical suggestions for designing effective tobacco prevention messages," Bolls said. "The way the human mind perceives and processes information in a persuasive message is the very foundation of any desired effect on targeted individuals. The PRIME lab at MU is dedicated to studying how very specific elements of health campaign messages engage attention and emotion so that messages can be produced that might actually help persuade individuals to adopt healthier attitudes and behaviors."

The researchers measured the physiological responses of 58 viewers while the viewers watched a series of 30-second anti-tobacco ads. The ads included fear messages that communicated health threats resulting from tobacco use (lung cancer, heart disease, etc.) or disgust content that focused on negative graphic images (dirty insects, blood, organs, etc.) or both fear and disgust content.

Electrodes were placed on the viewers' facial muscles to measure emotional responses. Attention, which was defined as the amount of mental effort participants expended to interpret the messages, was measured by taking participants' heart rates. To measure recognition, the participants completed a visual recognition task that consisted of watching brief video scenes (1 second) while pressing computer keys to indicate whether or not they believed the scene was from one of the ads they viewed during the experiment.

Provided by University of Missouri-Columbia