sexual orientation. However, there is much debate on the balance between nature and nurture in the determination. History This paradigm dates back to the 1950s. Even stronger versions were commonly stated in the 1960s and 1970s. One version, perhaps most associated with John Money, (who termed it the Adam principle), held that additional steps in the cascade to male identity were the recognition by parents and doctor that the external genitalia were male, which resulted in a male sex assignment, which in turn resulted in a male sex of rearing by parents and society, which in turn (coupled with the reinforcing appearance of male genitalia) resulted in a male gender identity. At least by implication, female gender identity simply required a female sex of rearing and lack of an obvious penis. See also Feminization References Sexual anatomy Zoology Male