Morality influences how individuals interpret sociopolitical issues and make decisions. Moral framing uses moral language to shape opinion, and moral appeals are persuasive messages that advance a position by explicitly invoking moral principles or values. This systematic review synthesized 34 publications comprising 57 individual randomized controlled experiments that examined the persuasive effects of moral framing. Results showed moral appeals can effectively shift attitudes and behaviors, particularly when aligned with an audience’s ideological values. Many studies have shown that liberals respond more favorably to individualizing appeals, whereas conservatives are more receptive to binding appeals. It remains unclear if moral appeals are inherently more persuasive. Studies found non-moral appeals were as or more persuasive, especially with low moral relevance. Moreover, moral framing sometimes led to backfire effects, reducing engagement among low-knowledge or ideologically resistant audiences. Findings highlight moral framing’s conditional nature, with persuasion outcomes depending on both audience characteristics and issue-specific factors. Tailoring moral appeals to audience values enhances their effectiveness, but scholars should be mindful of potential backlash when moral frames conflict with entrenched beliefs. By clarifying the conditions under which moral appeals succeed or fail, this study contributes to a more nuanced and effective use of moral communication in an increasingly polarized world.
