sentences:  In 1961, Sherfey's interest in female biology was intensified when she came upon the inductor theory, which demonstrated that the human embryo is female until hormonally “induced” to become male.Determined to popularize a fact that had lain in neglect since its discovery in the 1950s, Sherfey began researching the subject and familiarizing herself with a variety of disciplines, including embryology, anatomy, primatology and anthropology.Many of her findings appear in "The Nature and Evolution of Female Sexuality", which initially took form as an article contesting the existence of vaginal orgasm, published in the Journal of the American Psychoanalytic Association in 1966.