Pupil dilation when viewing strangers: Can testosterone moderate prejudice?

Undergraduate students, 27 white and 27 black, provided saliva samples for testosterone assay, completed measures of prejudice, and viewed pictures of black and white target persons. Pupil dilation was measured continuously w hile subjects viewed the pictures and thought about meeting the persons who m they were seeing. Testosterone interacted with prejudice, such that preju diced individuals who were low in testosterone showed large pupil dilation and prejudiced individuals who were high in testosterone showed small pupil dilation. The interaction of testosterone with prejudice in affecting dila tion was not related to the race either of the subject, or of the target be ing viewed.