Gonadal androgen and sociosexual behavior of male mammals: A comparative analysis.

Sexual, aggressive, and scent-marking behavioral patterns are altered by withdrawal and replacement of gonadal androgen in some mammalian species. Although in some animals peripheral organs related to the expression of these behavioral patterns may be affected by androgen, most behavioral influences are due to the effects of androgen on the central nervous system. Earlier experimental work dealing with species differences in androgen control of sexual behavior suggested that androgen influence was inversely proportional to the relative development of the neocortex. Although this evolutionary principle may play a role in the overall picture, recent work reveals that understanding species differences requires an analysis of factors that relate to the responsiveness of the neural tissue in areas of the central nervous system that are affected by androgen. Several aspects of social behavior of male mammals are markedly influenced by gonadal androgen. As our knowledge of these influences has developed, various hypotheses attempting to unify observations on several species and to explain physiological mechanisms have been formulated. The purpose of this review is to bring recent experimental findings to bear on an examination of some of these hypotheses and to offer some new perspectives. In several instances gaps in the information needed to focus upon questions of a comparative nature are apparent. A few years ago almost all of the experimental observations related to gonadal androgen dealt with sexual behavior. But we have recently learned that a variety of behavioral patterns in adult males that are not directly related to copulation are also influenced by androgen. From the comparative standpoint sexual, aggressive, and scent