"Do Health Messages Come from Mars or Venus?" The Effectiveness of Health Communication Depends on Gender Stereotypes in Messages.

Prior research suggests that health messages can affect men and women differently, yet these differences and their underlying mechanisms remain insufficiently understood. Based on the premise that many health messages are implicitly gendered, this randomized controlled experiment (N = 1116), conducted in a high-risk real-world context, investigates the effectiveness of implicitly gendered messages on psychosocial determinants of protective behaviors, including cognitive, attitudinal, and motivational dimensions, as well as behavioral intentions. Twelve public health messages, derived from commonly used communications and theoretical frameworks, were first evaluated according to their perceived masculinity or femininity, and their effects were then experimentally tested across participants. Results indicate that messages strongly aligned with gender stereotypes produce the largest differences in effectiveness between men and women. For example, authority-based messages (a masculine stereotype) are more effective among men, whereas messages emphasizing social reciprocity or concern for others (feminine stereotypes) are more effective among women. These effects emerge only when recipients are likely to engage in systematic processing, particularly when their political stance diverges from that of the message source (the French government). The results support the gendered message-recipient gender congruence hypothesis, rather than alternative explanations based on gender-specific processing styles, with substantial practical implications.