Sexual Orientation

Some terms

• Sex - sexual behaviour
• Gender - being male or female
• Gender identity - the male's association with the male role and the female's association with the female role.
• Sexual identity - one's self label or self-identification as heterosexual, homosexual or bisexual.

Sexual Identity

An individual's enduring sense of self as a sexual being that fits a culturally created category and accounts for one¹s sexual fantasies, attractions and behaviour. Savin-Williams, 1995. p.166)

Sexual Orientation

• what is it? how many are there? is the number increasing?
• inborn or learned?
• is it natural?
• is it "catching"?
• is it a choice?
• can it be changed?

Sexual Orientation

• an illness? an indication of illness?
• a quality of the self?
• a type of personality?
• a lifestyle?

Sexual Orientation


Sexual Orientation

• Is same-sex sexual behavior a "natural" biological variant?
• Observed in many species of animals in their normal habitat, all the higher primates, penguins, whales, sheep.
• Is not associated with fatality or sterility (no violation of natural selection)

Sexual orientation

• 1600s: sin
• 1700s: crime
• 1800s: sickness
• 1900s: immoral choice, innocent victim of biology
• 2000s: neutral, natural variant????

Left handedness

• Left-handedness: the history of a biological variation
• 1600 - dangerous, evil : burned at the stake, devil possessed (sinestral)
• 1700 - social repugnant - associated with bodily wastes
• 1800 - defective: need for correction, prevention
• 1900 - tolerant acceptance: a nuisance, handicap
• 2000 - civil right???
• Bush, Clinton, Perot all "lefties"


Sexual Orientation: A person's erotic and emotional orientation toward members of his or her own gender or members of the other gender (J. Shibley Hyde and J. DeLaMater).
Distinct preference for sexual partners of a particular gender in the presence of clear alternatives

Gay males and lesbians too may engage in male-female sexual activity while maintaining a gay sexual identity. Some gay men and women are married, but harbour desire for members of their own sex, and fulfil these in extramarital affairs. Some, often women, only come to an awareness of their homosexual inclinations later in life.

Ford and Beach (1951) found that in nearly two thirds of the preliterate societies they studied, male to male sexual interactions were viewed as normal and deemed socially acceptable for some people, especially as certain times of life, e.g. during rites of passage.

Kinsey Scale

0 Exclusively heterosexual with no homosexual
1 Predominantly heterosexual, only incidentally homosexual
2 Predominantly heterosexual, but more than incidentally homosexual
3 Equally heterosexual and homosexual
4 Predominantly homosexual, but more than incidentally heterosexual
5 Predominantly homosexual, only incidentally heterosexual
6 Exclusively homosexual (Kinsey 1948.)

Sexual Orientation

• Gay men and lesbians often recall childhood play preferences like those of the other sex (Bailey & Zucker, 1995). Childhood gender conformity or nonconformity was not only the strongest but the only significant childhood predictor of later sexual orientation for both men and women (Bell et al., 1981a).
• But most homosexual people report not becoming aware of same-sex attraction until during or shortly after puberty, and not thinking of themselves as gay or lesbian until around age 20 (Garnets & Kimmel, 1990).

Sexual orientation

Little is known about female-female sexual activity in non-western cultures. Evidence for female-to-female sexual behaviour was found by Ford and Beachinn in only 17 out of the 76 societies they studied. This cross-cultural evidence is consistent with data from our own culture. Here too, males are more likely to develop sexual interest in, or romantic relationships with, members of their own sex. (Katz, 1995; Laumann et al., 1994).

Erotic Plasticity

• Baumeister R. (2000)- The degree to which a person's sex drive can be shaped and altered by cultural, social, and situational pressures.
• Lack of plasticity: A person's sexuality is more rigidly pattered early in life, as a result of biological and/or childhood influences.

Women's sexuality

• Study hints at a finding reported recently by other researchers-that women's sexual orientation tends to be less strongly felt and potentially more fluid and changeable than men's (Diamond, 2000; Peplau & Garnets, 2000).
• Little evidence that biological factors are a major determinant of women's sexual orientation: "It remains more subject to personal choice and social influence" (Baumeister 2000, p.356).

Women's sexual orientation

• Women, regardless of sexual orientation, respond to both male and female stimuli (Chivers & others, 2002).
• More malleable: Victorian times seen as sexless till sexual desire awaken up male.
• More women spend periods of their lives identifying with different sexual orientations. Emphasize individual characteristics rather than gender when selecting a partner (Fox,1996).


• Negative attitudes towards gay persons prevade our western society. Homosexual behaviour is often percieved as distusting, or wrong, or unacceptable.
• Homophobia is the name given for a cluster of negative feelings and attitudes towards gay people, including intolerance, hatred and fear. There is some evidence that homophobic men are threatened by the possiblity of discovering male-male impulses in themselves.


• Homophobia is strong also towards bisexuals even amonst the gay subculture. Bisexual people are attracted to both males and females. They report that they can maintain erotic interests in, and romantic relationships with, members of both genders. Depending on how one defines bisexuality, perhaps 1% to 4% of the population is bisexual. Less would have a bisexual identity (Laumann et al., 1994). American women who are not exclusively homosexual are more likely to be bisexual rather than exclusively homosexual.(Diamant and others, 1999).


• Genetics
• Birth Order
• Chromosones
• Brain differences
• Hormones
• Socio-Biology

• Psychodynamic
• Learning theory
• Early sexual experiences

Biological Perspectives

Genetics and Sexual Orientation.

Considerable evidence exists that gay male and lesbian sexual orientations run in families (Bailey et al., 1993; Pillard, 1990). In one study, for example, 22% of the brothers of a sample of 51 predominantly gay men were either gay or bisexual themselves. This is nearly four times the proportion expected in the general population (Pillard & Weinrich, 1986). Although such evidence is consistent with a genetic explanation, families also share a common environment.

Runs in Families

"Studies indicate that male homosexuality is more likely to be transmitted from the mother's side of the family." Robert Plomin, John DeFries, Gerald McClearn, and Michael Rutter, Behavioral Genetics, 1997


Sexologist John Money (1994) agrees that genetic factors may play a role in the development of sexual orientation. However, genetic factors do not fully govern sexual orientation. Most researchers believe that sexual orientation is affected by a complex interplay of biological and psychosocial influences (Barlow & Durand, 1995).

Birth order

Men who have older brothers are somewhat more likely to be gay, reports Ray Blanchard (1997, 2001). Assuming the odds of homosexuality are roughly 3 percent among first sons, they rise to about 4 percent among second sons, 5 percent for third sons, and so on for each additional older brother.
The reason for this curious phenomenon-the "fraternal birth order effect-is unclear. Blanchard suspects a defensive maternal immune response to foreign substances produced by male fetuses. The maternal antibodies may become stronger after each pregnancy with a male fetus and may prevent the fetus' brain from developing in a male-typical pattern. Women with older sisters, and women who were womb-mates of twin brothers, exhibit no such sibling effect (Rose & others, 2002).


Researchers at the National Cancer Institute have found evidence linking a region on the X sex chromosome to a gay male sexual orientation (Hamer et al., 1993). The researchers cautioned that they had not found a particular gene linked to sexual orientation, just a general location of where the gene may be found. Nor do scientists know how such a gene, or combination of genes, might account for sexual orientation.

Hormonal Influences

Sex hormones strongly influence the mating behaviour of other species (Crews, 1994). Researchers have thus looked into possible hormonal factors in determining sexual orientation in humans.Testosterone is essential to male sexual differentiation. Thus, the levels of testosterone and its by-products in the blood and urine have been suspected as a possible influence of sexual orientation, at least in males. Research has failed to connect sexual orientation in either gender with differences in the levels of either male or female sex hormones in adulthood (Friedman & Downey, 1994). In adulthood, testosterone appears to have activating effects. That is, it affects the intensity of sexual desire, but not the preference for partners of the same or the other gender (Whalen et al., 1990).

Hormonal Influences and Sexual Orientation

What of the possible prenatal effects of sex hormones? Experiments have been performed in which pregnant rats were given anti-androgen drugs that block the effects of testosterone. When the drugs were given during critical periods in which the fetuses' brains were becoming sexually differentiated, male offspring were likely to show feminine mating patterns as adults (Ellis & Ames, 1987). The adult males became receptive to mounting attempts by other males and failed to mount females.

Hormonal Influences

Do prenatal sex hormones play a similar role in determining sexual orientation in people? There is suggestive evidence. For example, Meyer-Bahlburg and his colleagues (1995) interviewed groups of women exposed prenatally to DES--a synthetic estrogen. They found that these women were more likely to be rated as lesbian or bisexual than women who were not exposed to DES. We do know that the genitals of gay people differentiate prenatally in accord with their chromosomal gender (Whalen et al., 1990). It remains possible that imbalances in prenatal sex hormones may cause brain tissue to be sexually differentiated in one direction even though the genitals are differentiated in the other (Collaer & Hines, 1995).

Brain differences

• Hypothalamic cell cluster is larger in straight men than in women and gay men; same difference is found in male sheep displaying other-sex versus same-sex attraction.
• Anterior commissure is larger in gay men than in women or straight men.

Biological Correlates of Sexual Orientation

On average (the evidence is strongest for males), various biological and behavioral traits of gays and lesbians fall between those of straight men and straight women. Tentative findings‹some in need of replication‹include these: Brain differences

These brain differences and genetic and prenatal influences may contribute to observed gay-straight differences in:
• spatial abilities
• fingerprint ridge counts
• auditory system.
• handedness
• occupational preferences
• relative finger lengths
• gender nonconformity
• age of male puberty
male body size

Structural differences

Evidence suggests that there may be structural differences between the brains of heterosexual and gay men. In 1991, Simon LeVay, a neurobiologist at the Salk Institute in La Jolla, California, carried out autopsies on the brains of 35 AIDS victims--19 gay men and 16 (presumably) heterosexual men. He found that a segment of the hypothalamus in the brains of the gay men was less than half the size of the same segment in the heterosexual men. The same brain segment was larger in the brain tissues of heterosexual men than in brain tissues obtained from a comparison group of 6 presumably heterosexual women. No significant differences in size were found between the brain tissues of the gay men and the women, however.

The Structure of the Brain

LeVay's findings are intriguing, but they are preliminary. We do not know, for example, whether the structural differences found by LeVay are innate. Nor should LeVay's findings be taken to mean that biology is destiny. As Richard Nakamura, a scientist with the National Institute of Mental Health, commented, "This [LeVay's findings] shouldn't be taken to mean that you're automatically [gayl if you have a structure of one size versus a structure of another size" (Angler, 1991).

Brain Differences

•Interpretation of Brain Differences
• possible causes of difference
-- genetic instructions
-- hormonal events (fetal, pubertal, maternal)
-- post natal experiences (80% of synapses form after birth due to experience)
• non-causal correlation
• causal brain difference

Psychological Perspectives

Do family relationships play a role in the origins of sexual orientation? What are the effects of childhood sexual experiences? Psychoanalytic theory is the major psychological approach to understanding the origins of sexual orientation.

Psychoanalytic Views

Sigmund Freud, the originator of psychoanalytic theory, believed that children enter the world polymorphously perverse. That is, prior to internalizing social inhibitions, children are open to all forms of sexual stimulation. However, through proper resolution of the Oedipus complex, a boy will forsake his incestuous desires for his mother and come to identify with his father. As a result, his erotic attraction to his mother will eventually be transferred, or displaced, onto more appropriate female partners. A girl, through proper resolution of her Electra complex, will identify with her mother and seek erotic stimulation from men when she becomes sexually mature.

Psychoanalytic Views

In Freud's view, a gay male or lesbian sexual orientation results from failure to successfully resolve the Oedipus complex by identifying with the parent of the same gender. In men, faulty resolution of the Oedipus complex is most likely to result from the so-called classic pattern of an emotionally "close-binding" mother and a "detached-hostile" father. A boy reared in such a family may come to identify with his mother and even to "transform himself into her" (Freud, 1922/1959, p. 40). He may thus become effeminate and develop sexual interests in men.


• A girl who does not resolve her penis envy in childhood may "manifest homosexuality, exhibit markedly masculine traits in the conduct of her later life, choose a masculine vocation, and so on" (Freud, 1922/1959, p. 50). The residue of this unresolved complex is continued penis envy, the striving to become a man by acting like a man and seeking sexual satisfaction with women: lesbianism.
• In Freud's view, a gay male or lesbian sexual orientation is one result of assuming the gender role normally taken up by the other gender.


The findings of lengthy Kinsey Institute interviews with nearly 1000 homosexuals and 500 heterosexuals (Bell & others, 1981; Hammersmith, 1982). The investigators assessed nearly every imaginable psychological cause of homosexuality-parental relationships, childhood sexual experiences, peer relationships, dating experiences. Their findings: Apart from homosexuals' somewhat greater nonconformity, the reported backgrounds of homosexuals and heterosexuals were similar.


Homosexuals were no more likely to have been smothered by maternal love, neglected by their father, or sexually abused. And consider this: If "distant fathers" were more likely to produce homosexual sons, then shouldn't boys growing up in father-absent homes more often be gay? (They are not.) And shouldn't the rising number of such homes have led to a noticeable increase in the gay population? (It has not.)

Bem's theory: Exotic becomes Erotic (EBE)

It proposes that biological variables, such as genes, prenatal hormones, and brain neuroanatomy, do not code for sexual orientation per se but for childhood temperaments that influence a child's preferences for sex-typical or sex-atypical activities and peers. These preferences lead children to feel different from opposite- or same-sex peers--to perceive them as dissimilar, unfamiliar, and exotic. This, in turn, produces heightened nonspecific autonomic arousal that subsequently gets eroticized to that same class of dissimilar peers: Exotic becomes erotic (D. Bem,1996).

Early sexual experiences

• Sample of 11.000. Van Wyk and Geist, (1984). Sex play to orgasm.
• Those who have arousing or uncomfortable experiences develop differently. Early sexual contact seems to be a predictor of homosexual attraction.

The Socio-Biology of Sexual Orientation

• Evolution of Sexual Behaviour
• Reproductive = coitus when female is ovulating
• Non reproductive = everything else masturbation; paraphernalia; anal, oral, manual-sex; coitus before puberty, after menopause, when the female is sterile, using B.C., when not ovulating, when male is sterile, not ejaculating, same-sex behaviour


There are some reports of changed orientation (Nicolosi & others, 2000; Yarhouse & Burkett, 2002). In one report that was highly publicized by advocates of sexual reorientation, Robert Spitzer (2002) located, with assistance from "ex-gay" ministries and therapists specializing in sexual conversion, "200 subjects reporting a change from homosexual to heterosexual orientation."


When interviewed, only 54 percent of the females and 17 percent of the males, however, had achieved "exclusively opposite sex attraction." Critics questioned the accuracy of these after-the-fact retrospective memories and testimonials (there were no before-and-after measurements of sexual response). Even so, the difficulty locating people who had made a self-reported U-turn in sexual orientation suggested to Spitzer that sexual reorientation "may actually be quite rare.