The FOE Effect: Overestimated Prevalence of Opponent Extremists, and Miscalibrated Political Contempt

Americans’ hostility toward political opponents has intensified to a degree not explained by actual ideological polarization. We propose that political animosity is particularly driven by partisans’ overestimation of the prevalence of extreme, egregious views held by only a minority of opponents but imagined to be widespread. In contrast, we did not expect opponents’ more moderate positions to be overestimated or to account for much hostility. Across five studies (N= 5402; three preregistered), we examine issue extremity as an antecedent of attitude overestimation. A majority of liberals and conservatives agreed with their party’s moderate issues but most rejected their side’s extreme or “fringe” issues. Our findings offer three key advances: First, partisans consistently overestimated the prevalence of their opponents’ extreme, caricatured views but not opponents’ moderate policy views, which they actually tended to underestimate. This selective overestimation reveals a specific bias towards perceiving extreme or fringe partisan views as much more prevalent than they are, a phenomenon we describe as the Fringe Overestimation Error, or the FOE effect. Second, this overestimation is linked to partisan media consumption, which amplifies perceptions of opponent extremity. Third, partisans’ (over)estimation of political opponents’ agreement with extreme (but not moderate) issues consistently predicted cross-partisan dislike, which in turn predicted unwillingness to engage with opponents, foreclosing opportunities to correct misperceptions (Studies 2-5). When asked about the basis of their opponent dislike, participants even explicitly attributed animosity to extreme more than moderate issues, revealing that opponent dislike was based largely on views opponents did not have (Study 3).