Social dominance orientation: Cause or 'mere effect'?. Evidence for SDO as a causal predictor of prejudice and discrimination against ethnic and racial outgroups

The question of whether SDO is a cause or mere effect of intergroup attitudes and behaviors has been the subject of heated debate. Much of the research brought to bear on the question, however, has used cross-sectional data that is not best-suited for making causal inferences. Using data from a panel study that tracked UCLA undergraduates over several years, we find support for the notion that SDO is a cause, rather than 'mere reflection' of prejudice and discrimination against outgroups. Specifically, using cross-lagged analyses among White students, we show that SDO measured in 1996 has significant marginal utility for predicting prejudice against a series of ethnic outgroups, as well as self-reported ingroup friendship preference, four years later, controlling for their 1996 levels. Conversely, outgroup affect and ingroup friendship preference measured in 1996 fail to predict SDO levels in 2000 once 1996 SDO levels are taken into account. Implications of these analyses for the debate on the interpretation of SDO as a relatively stable orientation towards group-based hierarchy in society are discussed.