Partisan Stereotyping and Polarization in Brazil

In recent decades, Brazilian voters have grown polarized between supporters of the Partido dos Trabalhadores (Workers' Party, PT), known as petistas, and its opponents, known as antipetistas. What explains this animosity? One potential source of polarization is partisan stereotyping, a tendency for partisans to misperceive the social composition of both their own side's bases of support as well as their opponents'. We show that most Brazilians overestimate the extent to which petistas and antipetistas belong to party-stereotypical groups such as Afro-Brazilians, evangelical Christians, or poor or rich people. We then show that stereotyping is associated with polarization: The greater the bias in perceived partisan group composition, the greater the perceptions of partisan political extremism and feelings of social distance toward the partisan out-group.