Does Character–Audience Matching Increase the Persuasive Impact of Anti-Sugar-Sweetened-Beverage (SSB) Consumption Messages?

It is widely believed that persuasion is enhanced by including characters in a message whose features correspond with those of the audience. Matching on gender, age, and ethnicity may be especially appealing because these features are immediately perceivable. We examined the persuasive impact of matching on these variables using a large sample of real-world messages (<i>k</i> = 91) drawn from a single topic/context (messages that advocate for reduced consumption of sugar-sweetened beverages). Contrary to prediction, the data (<i>N</i> = 692) showed no significant main effects. Gender-matching, however, was moderated by prior SSB consumption such that it produced higher levels of perceived message effectiveness among heavier drinkers. Neither age- nor ethnicity-matching yielded a similar interaction. A composite similarity (gender + age + ethnicity) effect was observed though it was likely the product of gender-matching alone. The results suggested that the matching principle is intuitively attractive, but empirically suspect. There may be principled reasons to include demographically diverse characters in health campaigns, but anti-SSB message designers should keep their expectations low regarding advantages from demographic matching.