ABSTRACT
The neuroscience explanation of gender differences rests on a foundation of differential neurological organization shaped by a complicated mélange of prenatal genetic and hormonal processes that reflect sex-specific evolutionary pressures. The process of sexing the brain is a real wonder of nature: consider the immensely complicated interactions and permutations of chromosomal, genetic, enzymatic, and hormonal factors that go into it. Disorders of sex development individuals are useful to behavioral scientists who want to get to the bottom of gender differences because they defy our usual binary gender categories and expectations. Partial androgen insensitivity syndrome individuals are usually behaviorally intermediate in terms of gendered behavior. Transsexuals are persons who feel that they inhabit the body of the wrong sex. These individuals reveal the complication of sexing what all mammals are prior to that momentous sixth week—undifferentiated hermaphrodites—because they seem to defy the organizational-activation process.
