An Exploratory Study Examining the Interactive Effect of Descriptive Norm and Image Appeal Messages on Adults' Physical Activity Intentions: A Test of Deviation Regulation Theory.

This exploratory study examined the interaction between messages conveying descriptive norms and image appeals on adults' physical activity intentions. Using a pre-post experimental design, insufficiently active adults (N = 204) were randomly assigned to receive one of four messages, which included both a descriptive norm (prevalence of physical activity: high vs. low) and an image appeal (personality attributes: positive vs. negative). The results from an analysis of covariance, controlling for baseline physical activity intentions, revealed a significant interaction. Post-hoc analyses indicated that when the image appeal was positive, those who received the low descriptive norm had greater physical activity intentions than the high descriptive norm condition. No significant interaction was found for negative image appeals. Results provide preliminary evidence that physical activity intentions can be positively influenced even when physical activity is not considered the norm. Messages that include low descriptive norm information may benefit from including positive image appeals of those who do engage in physical activity, if aiming to increase physical activity intentions in insufficiently active adults.