The effects of disagreement and unfriending on political polarization: a moderated-mediation model of cross-cutting discussion on affective polarization via unfriending contingent upon exposure to incivility

Cross-cutting discussion is the foundation of deliberative democracy. However, previous research has reported inconsistent results regarding the effects of exposure to dissimilar perspectives on political polarization. This study aims to extend the literature by exploring how cross-cutting discussion influences affective polarization through unfriending and how this indirect effect is contingent upon exposure to incivility. The study analyzes panel data from a two-wave online survey conducted in South Korea (N = 890). The results show a significantly positive indirect effect of unfriending, suggesting that cross-cutting discussion further reinforces affective polarization via unfriending. Furthermore, the study identifies the boundary conditions for this mediating mechanism, showing that the mediated relationship of cross-cutting discussion on affective polarization via unfriending is stronger for those who are more exposed to incivility on social media. Lay Summary When social media users are exposed to different political views and disagreements, they can avoid and filter these by engaging in unfriending behavior. Our study examines the antecedents and consequences of unfriending. The results suggest that the uncivil environment of social media has led social media users to adopt unfriending strategies to avoid opposing viewpoints more aggressively. However, this avoidance mechanism also traps them in a filter bubble of like-minded users. Both exposure to incivility and selective avoidance further lead to an increasing distaste for other political parties among social media users.