RT Journal Article T1 Ingroup and outgroup effects on party Placement perceptions A1 Mauerer, Ingrid A1 Puy-Segura, María Socorro K1 Identidad colectiva K1 Polarización (Ciencias sociales) AB How do identities affect our political perceptions? Drawing on the social identity theory, we offer a new notion and empirical modeling strategy to study divergence in party placement perceptions. Our framework builds on the idea that membership in social groups has the potential to act as a social identity by systematically structuring perceptual divergence among groups. We conceptualize two consequences of social identity formation, ingroup favoritism and outgroup hostility: an ingroup effect brings a party closer to the preferred policy of the group; an outgroup effect pushes the party away. The approach permits detecting these effects and pinpoints the group-based characteristics producing perceptual polarization in multiparty systems using standard public opinion survey data. An application to the Basque region of Spain shows that over two decades, social identities around national sentiments and religion have produced the most perceptual divergence and polarization, whereas gender or social class do not structure party perceptions in the region. PB Cambridge University Press YR 2025 FD 2025 LK https://hdl.handle.net/10630/44703 UL https://hdl.handle.net/10630/44703 LA eng NO Mauerer, I., & Puy, M. S. (2025). Ingroup and outgroup effects on party placement perceptions. European Political Science Review, 1–22. doi:10.1017/S1755773925100234 NO Funding for open access charge: Universidad de Málaga DS RIUMA. Repositorio Institucional de la Universidad de Málaga RD 4 mar 2026