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.

近几十年来，巴西选民两极分化：工人党（PT）的支持者（被称为“petistas” ）和其反对者（被称为“antipetistas” ）。如何解释这种敌意？两极分化的一个潜在根源是党派刻板印象，党派人士倾向于误解自己一方和对手的支持基础的社会构成。我们表明，大多数巴西人高估了佩蒂斯塔和反佩蒂斯塔属于政党刻板群体的程度，例如非裔巴西人、福音派基督徒、穷人或富人。然后我们表明，刻板印象与两极分化相关：感知到的党派群体构成的偏见越大，对党派政治极端主义的看法以及对党派外群体的社会距离感就越大。