One Size Does Not Fit All: Mediating Effects of Perceived Character Similarity in Tailored Health Messages for Sexual and Gender Minority Young Adults.

This research examines how gender expressions in health messages influence perceived message effectiveness (PME) for sexual and gender minority (SGM) young adults through perceived character similarity. In an online experiment, 1,113 SGM young adults were randomly assigned to view six anti-smoking messages portraying one of four gender expressions: feminine, masculine, gender expansive, or multiple gender. Findings indicated that messages with multiple gender expressions increased perceived character similarity among SGM young adults compared to messages showing masculine expressions; perceived character similarity mediated the relationship between message exposure and PME. However, messages with multiple gender expressions were associated with lower PME than all other conditions. Furthermore, moderation analysis revealed nuanced differences in responses based on participants' gender identities. Theoretically, this study underscores the mediating role of perceived character similarity in tailored communication, while suggesting that other factors may also contribute to PME. The findings have practical implications for designing health campaigns that resonate with the diverse gender identity groups within the SGM community.