We evaluated the effect of the Backdoor Vignette relative to a control condition in which no vignette was presented and two vignettes that provide strategic points of comparison. The first comparison (the Race-as-Social-Construction Vignette) represents the position that race is socially constructed and not biologically meaningful. This is the view expressed at the press conference unveiling the draft human genome map, referenced earlier, and that has been expressed by many social scientists and geneticists (Omi 2001). The second comparison vignette (the Race-as-Genetic-Reality Vignette) represents the position that broad genetic differences exist between racial groups and asserts that genetic research confirms the validity of traditionally defined racial groups. This approach is seen in the scientific literature with increasing frequency and is well summarized by Risch and colleagues (2002). The two comparison vignettes represent contrasting and explicitly stated positions that racial groups do or do not vary genetically. In contrast to the Backdoor Vignette, which limits its focus to a single genetic variant, these vignettes argue that differences between racial groups are broad and general. We constructed a reliable multi-item measure of beliefs in essential racial differences, including several items developed for this study, that served as the primary outcome measure.
