Didactic and narrative persuasion: An experiment to promote colorectal cancer screening

We tested whether a didactic and a narrative video (i.e. educational content and personal stories versus irrelevant information) could boost colorectal cancer (CRC) screening intention directly and through cognitive predictors of CRC screening behavior. We also tested whether exposure to a story changed participants' affective forecasting, reducing the perception of negative emotions associated with CRC screening (disgust, embarrassment, and fear). The study was conducted online with a between-participants design and recruiting a convenience sample (N = 375). We found that, compared with watching the control video, being exposed to the narrative video about CRC screening was indirectly associated with greater screening intention via vicarious experience and positive attitudes, whereas watching the didactic video was positively associated with CRC screening intention only among participants who had received an invitation letter but did not get screened, and among those yet to receive an invitation to screen. In the latter group, screening intention was boosted through positive attitudes. Our findings do not confirm that stories change affective forecasting, but narration likely fosters messages acceptance through vicarious experience. We also found support for the effectiveness of physicians' recommendations in promoting CRC screening, an intervention that might be effectively administered through a generalized, cost-effective video.