Beyond Politics: The Role of In-Group/Out-Group Thinking in Shaping Trust in Non-Political Institutions

For a democratic society to function well, citizens need to accept public institutions as legitimate. This applies as much to political institutions (parliament, government) as to institutions that fulfill a non-representative, impartial role. A growing line of research shows that affective polarization – or the tendency towards in-group/out-group thinking among citizens – may impact democratic norms and support among citizens (e.g. Brookman et al., 2023; Berntzen et al., 2024). Yet, while the consequences of affective polarization for trust in political institutions have recently received some attention (e.g., Torcal & Carty, 2022; Janssen, 2024), less is known about its potential effects on non-political institutions. In our contribution, we focus on the relationship between affective polarization and trust in public institutions with an impartial function – focusing on both institutions of order (e.g., courts) and institutions of opposition (e.g., media) (Cook & Gronke, 2005). The legitimacy of these institutions relies precisely on their impartiality and their objective treatment of competing interests or views: For instance, a court is trusted when it is perceived to make judgements irrespective of special interests, social ties or political viewpoints. However, to appreciate institutional impartiality, one requires a basic acceptance of societal pluralism – i.e., the fact that society consists of different groups with diverse interests and viewpoints. Recent studies show that the heightened social identity distinctions associated to affective polarization tend to reduce tolerance towards other political groups (Peffley et al., 2022; Kokkonen & Harteveld, 2025). Based on this, we expect that trust in impartial institutions is lower among citizens engaged in stronger in-group/out-group thinking, because they do not subscribe to the pluralist foundations of these institutions. Another consequence of affective polarization may be that citizens base their trust on partisan/political arguments rather than on objective institutional performance. Next to the direct effect of affective polarization on institutional trust, we expect affective polarization to influence the causes of institutional trust. Specifically, citizens prone to in-/out-group thinking categorize the social world along the lines of “us’ versus “them” (Iyengar et al., 2012). This categorization may extend to evaluations of public institutions, which may be perceived to align with one’s in-group or out-group. Empirically, we expect highly affectively polarized individuals to base their institutional trust more on political or ideological positions. To study the relationship between affective polarization and institutional trust, we use panel data (LISS) from 2022 and 2023 collected in the Netherlands. Our analysis is threefold: we analyze 1) how affective polarization relates to trust in non-political institutions, 2) whether this relationship holds across different types of institutions (i.e., order vs. opposition institutions) and (left/right) voter groups, and 3) whether affective polarization moderates the relationship between institutional trust and partisanship or ideology. With our analysis, we make a novel contribution to the growing literature on the consequences of affective polarization, by assessing how in-group/out-group thinking has an impact beyond the political sphere, potentially harming the legitimacy of institutions that are essential for a well-functioning democratic state.