Testosterone and gonadotropin levels and r/K reproductive strategies.

It is proposed that different levels of testosterone are the physiological basis in males of the racial differences in sexual drive which form the core of the different r/K reproduction strategies documented by J. P. Rushton. There is direct evidence for higher testosterone levels in Negroids than in Caucasoids and indirect evidence from the incidence of cancer of the prostate. Prostatic cancer is a function of testosterone levels and shows increasing incidence from Mongoloids to Caucasoids to Negroids. It is further proposed that in females the hormonal basis of differential r/K behaviour lies in the level of gonadotropin.