When Disagreement Becomes Uncivil on Social Media: The Role of Passive Receiving and Active Expression of Incivility in Influencing Political Polarization

Exposure to cross-cutting viewpoints may not always play the deliberative role it is supposed to. This study uses both panel survey and social media data to examine how disagreement can trigger incivility, including exposure to and expression of incivility, and further elicit emotions and influence polarization. Results from the two-wave panel survey indicate that cross-cutting exposure has a polarizing effect first through promoting exposure to uncivil messages and expression of uncivil opinions, then through negative emotions. Notably, cross-cutting exposure can indirectly reduce polarization by first encouraging expression of uncivil opinions and then eliciting positive emotions, highlighting the importance of active expression. Analysis of data from the Hong Kong-based discussion forum HKDisc demonstrates that cross-cutting exposure is positively related to exposure to uncivil messages, and exposure to and expression of incivility predict polarization regardless of whether positive or negative emotions are detected in the uncivil content. This study provides empirical evidence of the effects of cross-cutting exposure and incivility on polarization at the individual and collective levels.