which set of processes is primarily responsible for the SMTH effect. We regard this chapter and the work summarized by Sidanius and Pratto ( 1999) as merely preliminary efforts at such an explanation.
Despite the lack of complete clarity as to the ultimate sources of the SMTH, it is nonetheless quite clear that gender and arbitrary-set dominance systems are not reducible one to the other, nor purely additive. Further, this suggests that a complete understanding of the psychology of gender cannot be reached until we appreciate the distinct gender differences in the predisposition to generate and maintain arbitrary-set hierarchies by means of economic exploitation and physical violence. Most importantly, understanding of discrimination and outgroup aggression will not be complete without appreciation of the fact that males are both the primary perpetrators of intergroup oppression, and also the primary and deliberate targets of this oppression as well.
Finally, what does this perspective imply about our ability to attenuate and possibly eliminate both gender and arbitrary-set discrimination? Of course, the answer to this question is directly dependent upon a theoretical understanding of the forces and factors driving these various forms of discrimination. In general, social dominance theorists have argued that a primary reason for our seeming inability to eliminate the plagues of gender, ethnic, and class discrimination is the fact that we have not properly understood the etiology and functions of these phenomena. Social dominance theorists suggest that these forms of social oppression, rather than being merely products of "improper socialization," simple ignorance, or the exigencies of capitalism, are primarily the result of inherent features of human and primate social organization.
Thus, while social dominance theorists doubt that we will ever be able completely to eliminate these forms of social oppression, a more thorough and valid understanding of their underlying dynamics should at least put us in a better position to try to attenuate and control some of the most ferocious manifestations of these forces. On the other hand, it seems clear that the elimination of discrimination will not be possible until most dominant-group members are at least willing to admit that discrimination continues to exist in modern society. Unfortunately, current empirical evidence indicates that a large majority of American Whites are still in denial about this ugly reality ( Kearney, 1997).