Social and Cultural Factors in Sexuality

311
Sexual Behavior
FIGURE
8.3
The Sexual Response Cycle
Masters and Johnson (1966) found that men show one primary pattern of sexual response, depicted in Part A, and that women display at least
three different patterns from time to time—labeled A, B, and C in Part B. For both men and women, sexual stimulation begins with the excitement phase, which is followed by intensified excitement in the plateau phase and the pleasurable release of tension in the orgasmic stage.
During the resolution phase, both men and women return to a state of relaxation. Following resolution, men (but not women) enter a refractory phase, during which they are unresponsive to sexual stimulation.
Refractory
period
Orgasm
A
Orgasm
C
B
Plateau
Plateau
Resolution
Excitement
Excitement
Resolution
Resolution
Resolution
Cycle in men
Cycle in women
(A)
(B)
Resolution
larger in men than in women. Its possible role in some aspects of human sexuality was
suggested by a study that compared the brains of men with a male gender identity to
those of male-to-female transsexuals (genetic males who feel like women and may
request surgery and hormone treatments to create more female-looking bodies). The
BnST in the male-identified men was larger than in the transsexuals. In fact, the transsexuals’ BnST was about the size usually seen in women (Zhou et al., 1995).
Rising levels of sex hormones during puberty activate increased sexual desire and
interest in sexual behavior. Generally, estrogens stimulate females’ sexual interest
(Burleson, Gregory, & Trevarthen, 1995). Androgens raise males’ sexual interest
(Davidson, Camargo, & Smith, 1979), but they may also do so in females (Sherwin &
Gelfand, 1987). The activating effects of hormones are also seen in reduced sexual
motivation and behavior among people whose hormone-secreting ovaries or testes
have been removed for medical reasons. Injections of hormones help restore these people’s sexual interest and activity (Sherwin, Gelfand, & Brender, 1985).
Generally, hormones affect sexual desire, not the physical ability to have sex (Wallen &
Lovejoy, 1993). This fact may explain why castration (removal of the testes) does not
prevent sex crimes by male offenders. Men with low testosterone levels due to medical
problems or castration show less sexual desire, but they still have erections in response
to erotic stimuli (Kwan et al., 1983). So a sex offender treated by chemical or physical
castration would be less likely to seek out sex, but he would still respond as before to
his favorite sexual stimuli (Wickham, 2001).
Social and Cultural Factors in Sexuality
Human sexuality is shaped not only by hormones but also by a lifetime of learning and
thinking. For example, children learn some of their sexual attitudes and behaviors as
part of the development of gender roles, as described in the human development chapter. The specific attitudes and behaviors they learn depend partly on the nature of gender roles in their culture (Baumeister, 2000; Hyde & Durik, 2000; Peplau, 2003).