Effects of Over-Time Exposure to Partisan Media and Coverage of Polarization on Perceived Polarization

Abstract

ABSTRACT America is said to be more polarized than ever before, and extensive research examines the causes and effects of political polarization. A less studied but more pronounced trend is that citizens perceive society and politics as sharply divided. We focus on news exposure as a key reason for these perceptions. We disentangle the unique effects of exposure to partisan outlets and to news coverage of polarization in general, whether in partisan or centrist news media. We rely on 9 months of online behavioral data (127,400,000 visits) from large samples in the U.S. and Poland (total N = 2,462 & 2,120), paired with a three-wave panel survey on participants' attitudes and perceptions. We measure individual exposure, over-time and unobtrusively, to partisan outlets as well as to news coverage of polarization through a fine-tuned BERT-based machine learning classifier. We find that both exposures increase perceived polarization, independently, in both countries. Yet, in both contexts, it is news coverage of polarization, regardless of whether it is ideologically left, right, or centrist news outlets, that is the strongest driver of perceived polarization. These changes are confined to personal-level polarization (perceived distance between oneself and members of the opposing party), while no measure significantly influences perceptions of society, more generally, as being polarized. These findings have important implications for our understanding of how the media’s increasing tendency to focus on conflict as a central reporting frame can be the driver of often exaggerated perceptions of partisan divisions.