Affective Polarization and Mental Health: The Case of South Korea.

CONTEXT: Existing studies find the effects of individual health on political outcomes, but relatively little attention has been paid to the opposite direction--that is, the effects of politics on health particularly in an era of affective polarization. While prior studies have examined both political and non-political consequences of affective polarization, they tend to focus on 'relational' aspects, rather than 'personal' ones. This study addresses this gap by examining mental health as a domain of the personal consequences of affective polarization. METHODS: This study uses public survey data collected in June 2025 in South Korea, which can be considered a hard test due to its ethnic homogeneity and universal healthcare system. It first analyzes the relationship between affective polarization and mental health. It then uses interaction models to examine whether partisan identity moderates the relationship. FINDINGS: First, we find that, unlike our theoretical expectation, affective polarization is not associated with mental health. Second, but interestingly, among individuals with weak partisan identity, affective polarization is negatively related to mental health. Yet, this negative relationship weakens as partisan identity strengthens and, moreover, the relationship even appears positive among those with strong partisan identity. CONCLUSIONS: Affective polarization tends not only to produce negative emotions such as anger, but also to erode social capital such as interpersonal trust and networks, deteriorating mental health especially among weak partisan identifiers. By contrast, strong partisan identifiers tend to experience not only greater enthusiasm but also support from stronger in-group networks in the face of affective polarization, making them less susceptible to its negative effects on mental health. Therefore, our findings suggest that affective polarization threatens citizens' personal lives beyond relational aspects.