Partisan News Media and Opinion Polarization: A Self-categorization Theory Approach

Abstract

This study explored the exact processes that might underlie the influence of partisan news media on opinion polarization. Consistent with self-categorization theory, exposure to partisan news was expected to indirectly create opinion polarization when the news exposure made one's party identification salient as opposed to its counterpart (i.e., Democrats vs. Republicans). A pretest/post-test experimental study (N = 364) provided evidence of the causal direction of the main effects as well as the mediation influence of the strength of one's party identification in this relationship. However, a moderated mediation test failed to prove interaction effects of partisan news exposure and the strength of ideological predisposition on the enhanced perception of one's party identification. Theoretical implications of these findings for limited media effects research paradigm as well as practical implications for news writers were discussed.