Sexual differentiation absence of the genes that generate male genitalia do not single-handedly lead to a female brain. The male brain requires more hormones, such as testosterone, in order to properly differentiate. These hormones are released due to a gene expressed during embryonic development. Sexual differentiation Sexual differentiation is the process of development of the differences between males and females from an undifferentiated zygote. As male and female individuals develop from zygotes into fetuses, into infants, children, adolescents, and eventually into adults, sex and gender differences at many levels develop: genes, chromosomes, gonads, hormones, anatomy, and psyche. Sex differences range greatly and
Sexual Preference (book) that while Bell "et al."′s suggestion that biological factors have a stronger influence on exclusive homosexuality than they have on bisexuality may seem plausible, it has not been directly tested and appears to conflict with available evidence, such as that concerning prenatal hormone exposure. The psychologist Bruce Rind credited Bell "et al." with disproving psychoanalytic theories about the development of homosexuality, along with the idea that childhood seduction causes homosexuality. The psychologist Mark Yarhouse wrote that while "Sexual Preference" is cited by proponents of a biological explanation, it relies on retrospective memory recall, which can be unreliable. The psychologist J.