How Sexual Desire Works- The Enigmatic Urge

by Frederick Toates

  Genes might act on the brain mechanisms underlying sexual desire, which would not preclude a contributory role for environmental influences. However, genes might act on something else, such as personality, physical appearance or style of childhood play (Hines, 2004), which, in turn, via different environmental experiences, contributes to sexual orientation. Examples of a possibility along these lines are given shortly. Adult hormonal profiles do not predict sexual orientation. The idea, once advanced, that gay males are deficient in testosterone and gay females have unusually high levels finds no support.

  A comparison of various species of animals leads to the following conclusion, which might tentatively be extrapolated to humans (Woodson, 2002). Hormonal influences acting on the very young brain normally tend to create a bias towards heterosexual attraction. However, early learning experiences also play an important role, such as either to reinforce or to reverse this tendency.

  One suggestion that could explain part of the effect is known as the ‘nice-guy theory’ (Buss, 2003). In these terms, male homosexuality is a spin-off from the selection of characteristics of the ‘nice guy’. Such traits as sensitivity and empathy tend to be attractive to women and so their possessors have achieved high levels of mating and thereby these genes have prospered in evolution. The fact that some possessors have an increased tendency to homosexuality is not sufficient to undermine the genes’ advantage in a heterosexual context.

  Although controversial, researchers have reported differences in the structure of the brains of homosexual men compared to heterosexuals (LeVay, 1991), specifically a nucleus of the hypothalamus (Chapter 2): the INAH-3 nucleus. In the sample studied, this was larger in heterosexual males as compared to homosexual and bisexual males, corresponding to its larger size in heterosexual males as compared to heterosexual women. As LeVay notes, even if substantiated, such a difference does not in itself prove this to be the basis of sexual orientation. Rather, in principle, it could be a consequence of differences in life experiences of people with different orientations. However, there are sex differences in a comparable nucleus of the rat brain and these arise from different exposures to testosterone in early development.

  Later studies suggested that a broader range of brain regions are different in structure according to sexual orientation (Savic and Lindström, 2008). Also a different pattern of activation of nuclei in the hypothalamus4 has been observed in response to what are suggested to be human pheromones. In response to stimuli emanating from under the arm of males, homosexual males showed a similar reaction to that of heterosexual females and different from that of heterosexual males (Savic et al., 2005), though the interpretation of this result has been disputed (Burke et al., 2010). Lesbians showed a response pattern similar to that of heterosexual men (Berglund et al., 2006).

  Trying to establish a precise timing

  A young homosexual man, 18 years old, in Chicago described when he first felt his future sexual orientation. He recalled that (McClintock and Herdt, 1996, p. 178):

  he was sitting in the family room with his parents watching the original ‘Star Trek’ television series. He reports that he was 10 years old and had not yet developed any of the obvious signs of puberty. When ‘Captain Kirk’ suddenly peeled off his shirt, the boy was titillated. At 10 years of age, this was his first experience of sexual attraction, and he knew intuitively that, according to the norms of his parents and society, he should not be feeling this same-gender attraction.

  By the time the boy reached puberty, his sense of ‘self’ involved a homosexual orientation.

  Studies give 10 years as the average age when sexual attraction, whether heterosexual or homosexual, is first experienced (McClintock and Herdt, 1996). This runs counter to the common assumption that the emergence of sexual attraction corresponds to the time of maturation of the testes and ovaries (12–14 years). A survey of a group of homosexual boys and girls in Chicago, revealed that the first same-sex attraction appeared at around 10 years of age, the first same-sex fantasy arising a little later at around 11–12 years, followed still later (13–15 years) by same-sex activity.

  So, is there a biological event happening at around the age of 10 years, which could help to transform a neutral image into one endowed with sexual attraction? A candidate is maturation of the adrenal glands (Chapter 2), a source of sex hormones5 in males and females (McClintock and Herdt, 1996). With maturation, the glands appear to secrete relatively large amounts of sex hormone into the blood. The hormone travels around the body and some enters the brain, where it has effects on the organization of brain processes that underlie sexual attraction. It is known that, in adults, sex hormones sensitize erotic thoughts, making them more likely to appear. So it could be that hormonal elevation is responsible for the first appearance of sexual attraction.

  Of course, the fact that two events occur together in time does not prove that the hormone caused an effect on the brain processes that underlie sexual attraction. So, McClintock and Herdt were led to consider a possible social cause. Could there be some event in the lives of young people that happens at around age 10 and which assumes great significance? The researchers could find no such significant social event normally happening then.

  They considered a possible explanation that combined biological, cognitive and social factors. The hormonal change might trigger changes in the brain that underlie interpreting the social world, so that the child assimilates notions of sexual attraction observed in adults. They suggest that this could explain the development of heterosexual attraction but not homosexual attraction. Heterosexual development would consist of ‘reading-off’ the cultural norms of their environment, whereas homosexual development would be counter to cultural norms and might well involve considerable prejudice.

  So, a hormonal change at around age 10 years might explain when the process of forming an orientation occurs. It could be seen as switching on a process of assimilating sexual information from the environment. However, it seems not to be able to explain the form of orientation. What is happening at around 10 years of age in the environment to determine sexual orientation? The next sections describe some suggestions.

  The role of conditioning

  What is considered a normal sexual orientation is surely to some degree set by conventions of society in the form of role models and reinforcement or punishment for signs of attraction to particular types of individual (Akers, 1985). Any reinforcement derived from actual sexual behaviour will tend to be strengthened if there is social approval of the kind of relationship involved. Conversely, disapproval might undermine the potential for positive reinforcement to be derived from an unconventional attraction. Kinsey et al. (1953) found that disapproval of heterosexual activity prior to marriage was a significant trigger to homosexual contact. Presumably in some social contexts, homosexual and heterosexual desires might be equally acceptable and this might contribute to bisexuality.

  Children tend to exhibit curiosity about the bodies of other children and many engage in low-level sexual interaction (Van Wyk and Geist, 1984). From peer contact and particularly with those slightly older, children learn the ways of the sexual world and things about the opposite sex (Storms, 1981). Between the ages of 12 and 15 years, ideas that encourage heterosexual behaviour are usually transmitted to the child within groups of same-sex friends.

  Other people use the existence of biological sex differences as indicators of how to treat the developing child, that is what is boy-appropriate or girl-appropriate behaviour, and thereby what kinds of behaviour to reinforce. These influences are such that most people become heterosexual, while it is anticipated that signs of homosexual attraction are likely to be punished, either explicitly or implicitly. However, Akers argues, upbringing might, explicitly or implicitly, reinforce homosexual attraction. The criteria and standards set for heterosexual attraction might be perceived as impossible to meet by the developing child, with a correspondingly increased tendency for a homosexual attraction. Excessive moralizing
might devalue heterosexual attraction.

  Adolescent sex play between boys or between girls might ‘accidentally’ reinforce homosexual attraction, which could then be further reinforced by fantasy based on the early experience (Van Wyk and Geist, 1984). Sensitized, it would seem, by testosterone, boys tend to be more adventurous than girls and might well find more willing male than female sex partners. This might partly explain the higher frequency of homosexuality amongst males than females. Boys also masturbate more than girls, which could strengthen the role of fantasy. Those boys who learned to masturbate by having this done to them by another male tend to prefer male partners when adult. In addition, some children who grow up to become homosexual claim to have experienced early urges towards homosexual contact prior to any experience, such that first experiences are likely to be rewarding (Akers, 1985). Many adult homosexuals have had earlier heterosexual experiences of some sort but found them less rewarding than their homosexual contacts. Some might have found initial heterosexual advances intimidating (Van Wyk and Geist, 1984). Once a trajectory is started it then tends to be self-reinforcing. Girls who had coerced sexual experience with older males have some tendency to prefer women sexual partners. A whole array of different experiences could blend into a feeling of being gender-atypical.

  The first experience of sexual arousal might have a particularly strong effect in setting future orientation, for example first masturbation while viewing an image or holding an image in mind. A study of a group of individuals in San Francisco found that sexual orientation, whether primarily heterosexual or homosexual, followed the orientation of their first sexual experience (Weinberg et al., 1994). However, this did not preclude some later feelings that were discordant with the initial orientation.

  Amongst the Sambia people of Papua New Guinea, and some other ethnic groups (Ford and Beach, 1951), boys are initiated into homosexual activity at around 7–10 years of age and this lasts for several years. Yet Sambia boys do not grow up with an exclusively homosexual attraction. Indeed, they mainly assume a heterosexual identity. This could be interpreted as the cultural norms prescribing acceptable adult behaviour powerfully influencing sexual orientation. It might equally be interpreted as a biologically determined predisposition coming to dominate in spite of early experience.

  A social learning model

  Storms (1981) proposed a theory of sexual orientation, based upon (a) conditioning and (b) early social experiences, comparing children who went on to become either homosexual or heterosexual. As the basic process of conditioning, he suggests that sexual arousal that is followed by its reduction with orgasm, for example the sequence of masturbation, will consolidate the link to the object of desire that is current at the time, either in reality or in fantasy. This much could be common to either orientation of desire or indeed to bisexual fantasy.

  Storms cites Kinsey’s evidence that the sexual experiences of boys prior to age 13 are mainly homosexual, whereas beyond this age they are mainly heterosexual. For girls, the pattern of change is similar but less marked. Another observation fits Storms’ theory: exclusive homosexuality is more frequent amongst men than amongst women. He accounts for this by noting that, amongst other factors, sexual arousal commonly appears earlier in boys (when still in homosocial groups) than in girls (when they are already in heterosocial groups).

  Another theory is discussed next and, beyond its opening assumptions, appears to be at odds with that just described.

  Exotic-becomes-erotic?

  Bem (1996) advanced the ‘exotic-becomes-erotic’ theory of desire orientation. It questioned the assumption that heterosexual desire is the unproblematic default position of the brain/mind and only deviations from this require explanation. Rather, following in the tradition of Freud, Bem suggests that the acquisition of either a heterosexual or homosexual orientation requires explanation, something which is accounted for symmetrically in his theory. Both male and female desire are similarly accommodated with the same proposal. One might suppose that bisexuality arises from finding both sexes exotic.

  The logic of Bem’s ‘exotic-becomes-erotic’ theory is as follows. For a given individual, whichever gender is perceived to be the most different (‘exotic’) becomes attractive. Exotic gets transformed into erotic by labelling of arousal. The exotic tends to be arousing because it triggers an emotion such as fear, but this arousal tends to get labelled as sexual attraction. If Bem is right, heterosexuality is no more ‘wired into’ the brain through the genes than is homosexuality. Rather, it is experience-dependent and the experience is within a culture that normally dichotomizes the genders, as exemplified by the term the ‘opposite sex’.

  The role of later experience

  The theories just described refer to different early childhood experiences comparing heterosexuals and homosexuals, whereas Gallup (1986) emphasizes the role of later experience. The foundations of his argument lie in evolutionary principles and the difference in optimal mating strategies (‘sexual agendas’) of men and women. Gallup suggests that heterosexual mating usually involves a compromise: the male has fewer sexual partners and less immediate gratification than he would desire, while the female must compromise with a less than ideal emotional commitment from the man.

  Gallup suggests that females become disillusioned with being lied to, betrayed and coerced, whereas males become disillusioned with limited access to females. In such terms, female homosexuality is a response to the negative experiences they have had in their sexual relations with men, whereas male homosexuality is a response to the frustration of thwarted expectations and limited access.6 Gallup observes that some 85 per cent of female homosexuals had experience of heterosexual intercourse prior to assuming a gay identity, whereas only 20 per cent of male homosexuals had prior heterosexual experience. Gallup notes that hostility and distrust towards men is relatively common in homosexual women, whereas such feelings directed towards women are uncommon in homosexual men. Following this line of logic, if evolution had been such that mating opportunities for men and women were equal there would be no homosexuality (Gallup, 1986).

  In these terms, orientation might not be dichotomous but rather on a sliding scale that can accommodate bisexuality.

  Asexuality

  Puberty, well uh, you know I had the hormones, uh stuff starting working there but I really didn’t have anything, nothing to focus it on. I did you know test the equipment so to say and everything works fine, pleasurable and all it’s just not actually attracted to anything.

  (Participant interviewed by Brotto et al., 2010, p. 612)7

  Asexual people can be defined by their agreement with the expression ‘I have never felt sexually attracted to anyone at all’ (Brotto et al., 2010). Defining asexuality in terms of lack of desire is entirely compatible with the definitions of heterosexuality and homosexuality in terms of preferred object of desire as directed towards another (Bogaert, 2006). Asexuals are not averse to sex as in feeling fear or disgust, but rather are indifferent towards it (Prause and Graham, 2007). For a number of such ‘asexuals’, this constitutes an orientation which they are happy with and, they believe, is rooted in biology (Brotto et al., 2010). Asexuals sometimes feel a romantic attraction to others, so asexuality is characterized specifically by a lack of the sexual incentive. Asexuals need to be distinguished from those who experience (often temporarily) the distress of hypoactive sexual desire disorder and might well seek treatment for this (Bogaert, 2006). As with the dimension of heterosexuality–homosexuality, one might locate desire somewhere on a continuum from hypersexuality to asexuality (Chasin, 2011). How could the asexual orientation arise?

  People self-identifying as ‘asexual’ commonly report pleasure derived from genital stimulation by masturbation but no link to any attractive other (Brotto et al., 2010). The chapter has earlier described the developmental formation of links between the three components of (a) genital arousal, (b) pleasure from the genitals and (c) attraction to another. So, for asexuals a link can form between
the genitals and pleasure but not between this process and an attractive other. How is this lack of a link to be explained? People destined to become asexuals might not interpret their arousal as arising from an attractive other and therefore they never form an association between other individuals and their arousal.

  When desire can overcome any incestuous aversion

  Palmyre stood straight up, and in her panic and misery she flew into a rage.

  ‘And even if it is true what’s it got to do with you? The poor boy doesn’t have much fun. I’m his sister. I might easily be his wife because none of you girls will look at him’…She earned his keep for him, and at night she could surely give him what everyone else refused him, a real treat that cost them nothing…in the depths of their dark minds lay instinctive desire and unpremeditated consent.

  (Émile Zola, 1887/1975, p. 62)

  Incestuous aversion is not absolute but can under some conditions be overcome: there are a number of exceptions to the universality of the taboo (Bagley, 1969). Incest rules across cultures do not invariably match the criterion of biological closeness. Anthropological reports describe children brought up together but who nonetheless marry each other. For example, some cultures permit brother–sister marriage. Incest was reported as ‘not infrequently practiced’ on the Polynesian island of Mangaia, including between brother and sister (Marshall, 1971). In the nineteenth century, amongst the isolated Mormon communities of Utah, a man’s marriage to his daughter or sister was not uncommon, a similar phenomenon being reported from rural Japan (Bagley, 1969). In the period between the world wars in rural Sweden, father–daughter incest was reported as ‘not uncommon’. It occurred in isolated farms, where there was no other sexual outlet for the father and the daughter assumed the role of wife. The actual wife, if she was still around, offered tacit approval to the relationship. Of course, as is commonly concluded from the Taiwanese study (Chapter 13), a marriage or other form of sexual relationship should not be taken as a reliable index of the presence of reciprocal sexual desire.