Moral Outrage Predicts the Virality of Petitions for Change on Social Media, But Not the Number of Signatures They Receive

Social media is a powerful tool for activists to share their perspectives, but concerns persist that the viral spread of online moral outrage may undermine collective causes in some ways. Analyzing posts on X ( n = 1,286,442) with URLs to petitions on www.change.org ( n = 24,785), we found that expressions of outrage were uniquely associated with the number of times posts were liked and reposted (virality). Mediation analyses showed that outrage was indirectly related to the number of signatures petitions received (via virality). However, outrage was associated with fewer signatures when controlling for virality. In contrast, expressions of agency, group identity, and prosociality were associated with more signatures but no more virality. The findings outline the factors linked to engagement with online petitions and describe how social media can amplify content which has no direct link to the sorts of effortful behaviors typically thought to be conducive to social change.