Testing the effects of certain versus hypothetical language in health risk messages

This paper tests how the certainty or hypotheticality conveyed through language can be harnessed to enhance the effectiveness of targeted messaging about health risks. We conducted two experiments with adult smokers ( n = 317) and middle school youth ( n = 321) from low-income communities in the context of pictorial cigarette warning labels. We manipulated hypotheticality of risk through verb modality: 1. non-modal (present tense, e.g., smoking causes cancer), and modal/hypothetical (2. may, 3. can, and 4. will). For adult smokers, definitive (present tense) wording led to greater health risk beliefs, compared to hypothetical wording, among adult males but not females. For youth, contrary to what might seem intuitive, the more hypothetical may verb modality was more effective than the present tense language in promoting health risk beliefs. Among youth, greater health risk beliefs were also associated with reduced susceptibility to use cigarettes. No differences in negative affect by hypotheticality of language were found for either population. We discuss these findings in relation to the theoretical implications for the concept of hypotheticality and the application of construal level theory to strategic health communication.