Intersubject variations in national identity ideology map onto variations in neural dynamics during geopolitical video viewing

When people watch the same political narrative, they often form different interpretations. Although prior research has shown that political ideology can shape shared neural responses to sociopolitical content, less is known about how individual differences in national identity ideology are associated with inter-individual similarity in neural dynamics during naturalistic viewing, particularly in sociopolitical contexts where national identity is highly salient in public discourse. We addressed this question across two studies in Taiwan by examining how Greater Chinese ideology relates to positive engagement and neural dynamics during naturalistic viewing of a pro-China video. In Study 1 (N = 52), higher Greater Chinese ideology was associated with greater positive engagement. In Study 2 (N = 60), participants underwent fMRI while viewing the same video. Intersubject representational similarity analysis showed that inter-individual similarity in Greater Chinese ideology was associated with inter-individual similarity in neural dynamics within the frontoparietal control network and default mode network. Notably, neural similarity was primarily observed among participants lower in Greater Chinese ideology, revealing an asymmetric pattern across the ideological continuum. These findings extend prior work on political ideology by demonstrating that national identity ideology is linked to both subjective experience and shared neural dynamics during political narrative processing in a non-Western context. HighlightsO_LINational identity ideology was linked to positive narrative engagement C_LIO_LIIdeology similarity mapped onto neural similarity in the FPN and DMN C_LIO_LIExperience and neural dynamics varied with national identity ideology C_LI