Social identity shapes antecedents and functional outcomes of moral emotion expression in online networks

There is increasing evidence that moral and emotional rhetoric spreads widely on social media and is associated with intergroup conflict, polarization, and the spread of misinformation. However, this literature is largely correlational, making it unclear why moral and emotional content drives sharing and conflict. In this research, we examine the causal impact of moral-emotional content on sharing decisions and examining how social identity shapes the antecedents and functional outcomes of decisions to share. Across five pre-registered experiments (N = 2,498), we find robust evidence that the inclusion of moral-emotional expressions in political messages causes intentions to share the messages on social media. Moreover, individual differences in the strength of partisan identification and ideological extremity are robust predictors of sharing messages with moral-emotional expressions, even when accounting for attitude strength. But we only found mixed evidence that brief manipulations of identity salience increased sharing. In terms of functional outcomes, when partisans choose to share messages with moral-emotional language, people perceive them as more strongly identified among their partisan ingroup, but less open-minded and less worthy of conversation with outgroup members. These experiments highlight the causal role of moral-emotional expression in online sharing intentions, and how such expressions in online networks can serve ingroup reputation functions while hindering discourse between political groups.