Friedman R C, Wollesen F, Tendler R
J Nerv Ment Dis. 1976 Oct;163(4):282-8. doi: 10.1097/00005053-197610000-00008.
Despite differences in psychological development and personality structure, blood levels of testosterone and estradiol were equivalent in two monozygotic male twins of divergent sexual orientation.
尽管心理发展和人格结构存在差异,但性取向不同的一对同卵双胞胎男性体内的睾酮和雌二醇水平相当。