On the behavioral consequences of infrahumanization: the implicit role of uniquely human emotions in intergroup relations.

Four experiments confirmed the hypothesis that people discriminate the out-group on the basis of the expression of uniquely human emotions. In Study 1, using a lost e-mail paradigm, the expression of a uniquely human emotion resulted in "nicer" replies when the sender was an in-group compared with an out-group member. The same pattern of results was obtained in Studies 2 and 3 using a conformity paradigm. In addition, perceived similarity was measured and proposed as a potential underlying mechanism (Study 3). Finally, using an approach-avoidance procedure, Study 4 showed that people not only deprive the out-group of positive consequences as in the former studies but that people also act against the out-group. The role of infrahumanization underlying prejudice and discrimination is discussed.