This study tested the hypothesis that threats related to infectious diseases
would make persons less willing to affiliate with out-groups and that feelings
of disgust and beliefs about the out-group members would mediate this effect. To
test this hypothesis, American participants of European descent were presented
with either a disease threat or control threat. Then they were shown a
photograph of someone of the same race or different race. Participants were
asked to indicate whether they would avoid the target person and to state their
emotional and cognitive responses to the person. As predicted, disease salience
decreased the desire to affiliate with out-group members, and both feelings of
disgust and beliefs about the infection risk posed by the target person mediated
this relationship.