British Journal of Social Psychology (2003), 42, 187–198 © 2003 The British Psychological Society www.bps.org.uk Social dominance orientation and gender: The moderating role of gender identity Marc Stewart Wilson* and James H. Liu Victoria University of Wellington, New Zealand The aim of this research was to investigate the claim that gender differences in levels of social dominance orientation (SDO; Pratto, Sidanius, Stallworth, & Malle, 1994), a personality variable measuring a general predisposition towards anti-egalitarianism, are essentially invariant (Sidanius & Pratto, 1999). Previous ndings have indicated that (regardless of covariate) males display higher levels of SDO than females. Two studies were conducted to test the expectation (derived from social identity theory) that the gender–SDO relationship would be moderated by strength of gender group identi- cation. Both samples (150 non-students and 163 students) completed the full SDO 6 measure, and measures of gender group identication. Consistent with predictions, strength of gender identication was found to moderate the gender–SDO relation- ship, such that increasing group identication was associated with increasing SDO scores for males, and decreasing SDO for females. This result raises questions concerning the theoretical basis of social dominance theory, and whether gender group membership should be accorded a di fferent status from other ‘arbitrary-set’ group memberships. One might be forgiven for anticipating that, should anyone profess the expectation that women not only consider that group-level equality is more desirable than do men but that this difference will be invariant (include any covariate of your choice), such a position would prove short-lived. Yet this is exactly the hypothesis proposed by the authors of social dominance theory (Sidanius, Levin, Liu, & Pratto, 2000; Sidanius, Pratto, & Bobo, 1994) and, as yet, there is little data to suggest that this is anything other than the case. It is our intention to suggest a potential moderator of the gender– SDO relationship, specifically gender group identification. According to social dominance theory (SDT; Pratto et al., 1994; Sidanius, 1993; Sidanius & Pratto, 1999) post-industrial human societies are conceived as group- oriented social hierarchies. These hierarchies function to maintain human survival over the evolutionary period. On this basis it is argued that most forms of intergroup oppression and conflict serve the function of establishing and maintaining particular group-based, hierarchical social systems (see also Ng, 1980). Additionally, human social systems are argued to be andrarchical in nature (Sidanius, 1993) in that males will hold disproportionate political power. Given the sociobiological origin of SDT it comes as *Requests for reprints should be addressed to Dr Marc Stewart Wilson, School of Psychology, Victoria University of Wellington, PO Box 600, Wellington, New Zealand (e-mail: Marc.Wilson@vuw.ac.nz). 187