Polarization and positivity effects: Divergent roles of group entitativity in warmth and competence judgments

•The effect of entitativity on group perception is controversy.•Entitativity exerted a polarization effect on warmth judgments.•Entitativity exerted a positivity effect on competence judgments.

Previous studies have obtained mixed results regarding the influence of entitativity on group judgments. The present research aimed to make sense of the inconsistent results by examining the effect of entitativity on warmth and on competence, inspired by Fiske's seminal work suggesting that group judgments are made in terms of two fundamental dimensions. In Study 1, the target group was a novel group; its entitativity was manipulated by an instruction set regarding common goals and interdependence of group members. We described the target group as positive/negative on a warmth (Study 1a) or competence (Study 1b) dimension with segments of behavior statements. In Study 2, we selected four kinds of real social groups as target groups based on the stereotypes that people had held toward them. The entitativity of these four groups was manipulated by pictures depicting the similarity and interdependence of the group members. In both studies, participants rated the target groups in terms of warmth and competence. The results revealed that entitativity exerted a polarization effect on warmth and a positivity effect on competence judgments. The implications about entitativity and formation of and changes in impressions about groups are discussed.