The social life of health-promotion messages: Message effects in complex information environments

n rich, dynamic information environments, health-promotion messages are often viewed in close spatial and/or temporal proximity to thematically-related messages which may be congruent or contradictory in valence and source. For instance, young adults frequently encounter competing alcohol-related content from alcohol brands and health officials, partygoing peers and concerned parents. Which voices prevail when encountered in close succession and why? While persuasion research focuses on optimizing individual message types (e.g., anti- or pro-alcohol messages), acute, within-situation message competition is underexplored, limiting the predictability of message effects. We directly compared effects of competing message types to understand relative effects and examined emotional responses and perceived relatability of message content as potential mechanisms underlying message competition. Across three studies (N = 468), participants viewed a large sample of messages (N = 190) of different types (pro-, anti-, and non-alcoholic messages from professional and peer sources). Using within-subject designs, we measured the relative impact of these message types on alcohol craving and mechanisms driving these effects. Pro-alcohol messages were more impactful than anti-alcohol messages, especially among frequent binge drinkers. Although emotional responses and perceived relatability with the alcohol-related content were relevant mechanisms for both pro- and anti-alcohol message effects, both mechanisms were more strongly coupled to craving in response to pro- (vs. anti-alcohol) messages. Results demonstrate the importance of studying acute message competition and highlight potential areas of interference between message types (e.g., when emotional anti- and pro-alcohol messages are viewed in close proximity).