Enhancing the effectiveness of persuasive health messages on Facebook: Effects of tone and social distance on intention to quit smoking[Renforcer l’efficacité des messages persuasifs en santé sur Facebook : effets du ton et de la distance sociale sur l’intention d’arrêter de fumer]

• Objective Currently broadcasted on social networks anti-smoking persuasion campaigns towards young people, focus on motivation. This research aims to understand the effectiveness of the tone of a message shared on social networks. It draws on self-determination theory (SDT) to account for motivational processes and on construal level theory (CLT) to understand the role of social influence in this context. • Methodology A pretest and experimental study were conducted with 203 smokers aged between 18 and 34 years. • Findings Results show that the most effective combinations for promoting an intention to get information and quit among young people are either a supportive message tone associated with a high social distance between the message sender and the receiver, or a constraining message tone associated with a low social distance. • Managerial implications This research highlights the importance of fostering autonomous (versus controlled) motivation to generate behavioral intentions in the context of persuasive health communication. This research contributes to the effectiveness of persuasive Facebook campaigns conducted by public health organizations. • Originality The originality of this work lies in the mobilization of SDT in a context of persuasive communication and its combination with CLT which enrich the understanding of the effects of the message tone on motivation and intentions.