Motivated Reasoning and Partisanship: Explaining the Political Polarization Over Science

This study examines the political polarization of public trust in science across Europe, focusing on the roles of motivated reasoning and political partisanship. We distinguish between impact science, which often entails regulatory constraints on industrial activity, and production science, which supports technological and economic development. While prior research has largely centered on the U.S., European data reveal similar ideological patterns: left-leaning individuals exhibit greater trust in science overall, and particularly in impact science, while right-leaning individuals show greater trust in production science. These findings suggest that the politicization of science is domain-specific. We find evidence for both motivated reasoning and partisanship as drivers of science polarization. Education amplifies ideological differences in trust toward impact science, consistent with motivated reasoning, while closeness to a particular political party amplifies ideological differences in trust toward science in general and impact science, highlighting the role of partisanship. Exploratory path analysis indicates that partisanship exerts a greater influence than education. Our findings underscore that polarization is most pronounced in scientific disciplines and claims that challenge industrial interests and align with social welfare goals, and that partisanship plays a central role in shaping public trust in this scientific domain.