Polarizing reply patterns in comment sections of a large German news outlet

Abstract Many studies suggest that social media users prefer information that aligns with their worldview (congeniality bias). However, while this bias has been shown for information consumption behaviour (selective exposure), it is unknown whether the preference for like-minded content also characterizes social media interactions in which users reply to previous comments (selective response). Recent work has provided evidence that users exhibit an uncongeniality bias – a preference to reply to attitudinally uncongenial comments – when the affordance to reply is given. By investigating two years of user activity on the comment sections of a large German online news outlet, the present work addresses the question of whether an uncongeniality bias can be found in the field. Here we show that participants in comment sections are more likely to reply to a comment the less this comment is liked in the community (uncongeniality bias); that disliked comments tend to receive replies that are liked by the community and vice versa (antagonism); and that votes on replies are more extreme than votes on original comments (polarization). These results suggest that social media behaviour is not always driven by congeniality. Instead, users in comment sections exhibit antagonistic behaviour, and this antagonism may contribute to societal polarization.