Systematic Review and Evidence Gap Maps of Affective Polarization Research

Abstract: Affective polarization – defined as the disparity between in-party positive sentiment and out-party negative sentiment – has become a central concern due to its relation to democratic backsliding, declining trust, and social fragmentation. While once seen as a mere US phenomenon, recent studies reveal its global relevance across diverse political systems. Based on a systematic review, we present two evidence gap maps that offer an overview of existing research on determinants, consequences, and interventions. Although affective polarization has been linked to severe societal impacts, systematic analyses remain scarce. Our maps indicate the relative dominance of political science in affective polarization research and reveal gaps, especially in non-Western contexts and regarding behavioral outcomes. By identifying these blind spots, this review provides a roadmap for future research and informs strategies to mitigate affective polarization’s effects. Meta-analyses based on evidence gap maps are proposed as a tool for structuring and advancing future, ideally interdisciplinary, research.