People who posted health messages on social media subsequently became more likely to act on those, not wanting to appear as hypocrites

When audiences become advocates: Self-induced behavior change through health message posting in social media. Robin L. Nabi et al. Computers in Human Behavior, May 23 2019. https://doi.org/10.1016/j.chb.2019.05.030

Highlights
●    Posting a health video to Facebook enhanced the poster’s own health behavior.
●    Message sharing was best predicted by intensity of emotional response.
●    Health behavior self-efficacy also boosted message sharing.
●    Directives to share the message did not boost sharing behavior.

Abstract: Couched within the self-effects paradigm of social media influence, this research examines how posting a health promotion message to one’s social media influences one’s own, versus others’, later health behaviors, with emphasis on emotional intensity and message sharing directives. 382 participants viewed one of eight versions of a melanoma awareness video and were given the opportunity to post it to their Facebook page. Video sharers reported increased sun safety behavior one week later, even after accounting for a range of sun safety-related predictors. Emotional intensity and self-efficacy emerged as key message sharing predictors. These findings align with cognitive dissonance theory, offering unique evidence in a mediated context with relatively enduring effects, and expands the dialogue about the self-persuasive power of social media.