Infra-humanizing outgroups involves considering outgroups less human and more animal-like than the ingroup, which is perceived, in essence, as fully human. In this article, the first section presents the theoretical background of infra-humanization and distinguishes it from related concepts, such as dehumanization. The three basic hypotheses of the theory are then presented with a summary of empirical evidence. Social implications follow. Reasons for the pervasiveness of the phenomenon are examined as well as conditions that lead a specific outgroup to be infra-humanized. We also explore the consequences of infra-humanization, such as a lack of forgiveness for the outgroup and the ingroup's justification for past misdeeds against the outgroup, rather than guilt. Policy issues center on ways to combat essentialism, walls of difference between groups, and irrational symbols of superiority. The roles of egalitarian values and of deprovincialized intergroup contact are emphasized.