The Disappearance of Political Moderates Online: How the Privacy Function of Social Media Amplifies Observed Political Polarization

Abstract This article contends that when the privacy function of social media is used for politically relevant audience curation, users may take more partisan stances than they would otherwise, which therefore amplifies the observed political polarization. The privacy function allows users to selectively disclose their content to like-minded people and hide it from out-groups. We argue that, in a safe space created by using the privacy function, people tend to express more partisan stances to impress their in-groups. Through an experiment conducted in Hong Kong, where political polarization between pro-democracy and pro-establishment camps has intensified over the years, we created a social media-like environment for participants and demonstrated that those who were provided with the privacy function were more likely to disclose content to in-groups than to out-groups and, more importantly, exhibited stronger stances on polarizing issues. This article contributes to the understanding of the relationship between social media and political polarization and emphasizes the need to reassess the robustness of the observed polarization level on social media in various societies.