The social significance of the backdoor-to-eugenics hypothesis hinges on the idea that beliefs in racial difference are not a peripheral but a key element of racism. Are they? Beliefs in racial difference occupy a central place in the sociology of racism. According to Omi and Winant (1994:71), “A racial project can be defined as racist if and only if it creates or reproduces structures of domination based on essentialist categories of race” (emphasis in original). In Feagin’s (2001:70) theory of systemic racism in the United States, “the perpetuation of systemic racism requires an intertemporal reproducing not only of racist institutions and structures but also of the ideological apparatus that buttresses them.” Categorization of people into distinct groups (such as black and white) is so central to social psychological theory on prejudice that the Handbook of Social Psychology (Brewer and Brown 1998:556) states that “social categorization, as a fundamental cognitive process, is the sine qua non for all current theories and research in intergroup relations.”
