The Power of Social Media Bios: How Common Profile Content Unintentionally Signals Political Ideology and Shapes Prejudice

Social media bios are ubiquitous yet understudied identity signals, persistently visible to diverse audiences. Despite often non-political intent, such cues may be politicized in perception, with consequences for intergroup bias. Across four studies (N = 2,084), we test how commonplace bio content—occupations, hobbies, family roles, religious affiliations, pronouns—can unintentionally signal political ideology and shape prejudice. In Study 1, partisan-leaning bios were perceived as politically motivated, especially by outgroup members, who attributed greater political intent than signalers intended. Social media users whose bios contained outgroup signals were seen as less warm, competent, and trustworthy, and more threatening, toxic, and misinformed. Studies 2–4 extended the influence of bio content on behavioral contexts: influencing the perceived toxicity and valence of user comments (Study 2), discrimination in online marketplace interactions (Study 3), and simulated hiring scenarios (Study 4), each revealing discrimination toward users with outgroup-congruent bios. Findings show how subtle online self-presentations can be politicized, fueling prejudice and discrimination, with implications for signaling theory, meta-perception, and interventions to reduce polarization.