Designing Effective Testimonial Pictorial Warning Labels for Tobacco Products.

Warning labels on tobacco products sometimes feature images and stories of real people whose health has been affected by smoking. We examined effects of some of the design elements that may contribute to the effectiveness of these testimonial pictorial warning labels (PWLs). Beginning with a testimonial PWL that contained an image of a person and a basic warning statement (e.g., "Smoking can kill you"), we examined the impact of adding: (a) text detailing the person's name, age and health status (identifiers); and (b) explanatory statements that elaborated on the basic warning using a testimonial or non-testimonial message. In an online experiment, 1255 adult smokers in the United States were randomly assigned to one of six experimental conditions (2 [identifier: none/identifier] × 3 [explanatory statement: none/non-testimonial/testimonial]), or a control condition (text only warning labels that currently appear on packs in the United States). In each condition, participants were exposed to multiple labels each focused on a different health effect. Effectiveness was assessed using emotional responses, engagement and behavioral intentions measured immediately post-exposure, and quit attempts measured at five-week follow up. Testimonial PWLs were more effective than the text only labels. However, there was little evidence that adding identifiers or the explanatory statements enhanced effectiveness; rather, there was some evidence that testimonial explanatory statements reduced effectiveness. These findings suggest that the most effective design for testimonial PWLs may be to combine a basic warning statement with an image of a real person, without any additional textual components.