Partisan Dehumanization in Brazil's Asymmetrically Polarized Party System

An ugly manifestation of polarization is partisan dehumanization, a form of moral disengagement from and support for aggressive or even violent treatment of one's opponents. Brazil offers a useful case to explore the relative importance of in-group sympathy or out-group antipathy as sources of dehumanization, since its voters are polarized between supporters and opponents of a single party, the Partido dos Trabalhadores (Workers’ Party, PT). Using survey-experimental data from a convenience sample, we show that partisan dehumanization can stem from either in- or out-group bias. Both PT partisans, known as petistas, and PT opponents, known as antipetistas, dehumanize their opponents. For petistas, in-group favoritism drives dehumanization of their opponents. However, since the only thing that unites all antipetistas is their dislike for the PT, out-group animosity is the critical factor driving their dehumanization of petistas. We also find that dehumanization is associated with the intensity of positive or negative partisanship and perceptions of social and moral distance between opponents. However, perceptions of out-group threat and Social Dominance Orientation do not enhance dehumanization. Our findings contribute to understanding the roots of partisan dehumanization and polarization in Latin America and beyond.