ABSTRACT
Human Sexual DevelopmentSexual development occurs in two phases. The first organizational phase occurs during gestation and involves the development of the internal and external genitalia and most or all of the brain circuits that provide for adult sexual behavior. The second, or activational, phase of sexual development takes place at puberty and throughout adulthood, when under the influence of sex hormones, both male and female anatomy mature to their full adult form and function. The brain circuits that support adult sexual behavior also become fully functional under the influence of the pubertal surge of sex hormones. How sex hormones influence these processes will be examined in Chapter 4.
