Testicular hormones reduce individual differences in the aggressive behavior of male mice: A theory of hormone action

Abstract

A chronology of theoretical development in studies of the role of testicular hormones in murine aggression is presented. Evidence which brings into question the generality of current theory is reviewed, and the implications of this evidence for the direction of future research are discussed. A new method by which to characterize individual differences in aggressive behavior is described, and recent data which provide the basis for the development of a new theory are presented. It is theorized that testicular hormones reduce individual differences in the aggressive behavior of male mice, and that this behavioral "homogenization" is mediated by a testicular-hormone regulated "discrimination mechanism," possibly localized within the mouse olfactory system. The generality of this theory and the implications for other hormone/behavior systems are also discussed.