Studies on wild house mice iv: On the heredity of testosterone and readiness to attack

An attempt was made to determine the role of the Y chromosome in the development of aggression in wild house mice. The aggression‐eliciting property of testosterone depends not only on circulating adult testosterone, but also on perinatal sensitization of the central nervous system to this steroid. Results of crosses between aggressive (SAL) and non‐aggressive (LAL) mice indicate that adult plasma testosterone in these mice is determined by the autosomes, high testosterone levels being dominant over low levels. Conversely, the Y‐chromosomal effect seems related to perinatal processes that sensitize the brain for testosterone.