Intensified Online Opinion Clashes with Salient Group Identity

We collect data from Hong Kong’s foremost news media outlets’ Facebook pages from 2019 to 2020 to examine clashes of opinion on the social media platform. We find that specific writing habits signify users’ backgrounds and elicit group segregation cues from readers. An increase in pro-police comments written in Simplified Chinese induces a more polarized reaction from the opposite side compared with comments written in Traditional Chinese. The opposite side produces more anti-police comments and demands for regional independence in response. However, content generated by suspected internet water armies alleviates the clashes. The results reveal the factors that affect opinion polarization on social media platforms. They demonstrate the need for debiasing intervention and regulation