How Sexual Desire Works- The Enigmatic Urge

by Frederick Toates

The next chapter builds upon the present one by considering the negotiation of initial and later sexual behaviour.

  In summary

  Early experiences mould a child’s social reactions and the experience and later expression of sexual desire can be best understood in this broader context.

  There is a developmental process underlying sexual desire and it involves forming links between bodily arousal and stimuli (‘incentives’) in the environment.

  Incest avoidance appears to arise from a form of ‘negative imprinting’.

  Fourteen Setting the trajectory: link to adult sexuality

  We’ve come a long way culturally in 10,000 years but evolutionary psychologists would argue that if we are to understand the human mind then we would do well to realise that that mind is the same one that scanned the plains of equatorial Africa in days of our Pleistocene ancestors.

  (Workman and Reader, 2014, p. 470)

  The last chapter looked at how the bases of sexual desire are established in the child. The present chapter revisits this topic in the context of how processes established in the child are revealed in:

  the emergence of adult sexual behaviour;

  changes and stability in adult behaviour.

  It first looks at how brain development is manifest in sexual risk-taking (by also drawing on earlier chapters that described levels of the control of behaviour) and it then considers the direction taken by adult sexual desire and expression.

  Transitions between adolescence and young adulthood: brain bases

  Adolescence and young adulthood represent a stage during which there is a strong tendency to engage in risky activities, including dangerous driving, drug-taking and unsafe sexual behaviour (Steinberg, 2008). For many, it is the time of first sexual intercourse (Hawes et al., 2010). Educational programmes designed to warn of risky activities by appealing to rational cognition appear to have a very limited effect. Do young people fail to appreciate the risks, as a result of using wrong and irrational calculations? Do they trust in their own invulnerability? It is not a failure of knowledge; the beliefs and calculations of 16-year-olds are much like those of adults.

  A study of adolescents found an association between (a) high-risk behaviours such as drug-taking and unprotected sex, and (b) the personality characteristic of impulsive sensation-seeking (Robbins and Bryan, 2004). High-risk behaviours were associated with a low value of ‘future orientation’.

  In the psychology literature, sensation-seeking and impulsivity are commonly described as synonymous. It is easy to see why: impulsivity could prove an effective means to obtain high stimulation. However, although their effects commonly combine in particular instances of behaviour, they can be distinguished. For example, one could plan to seek high sensations without acting impulsively. Changes in these two features of behaviour occur over development (Harden and Tucker-Drob, 2011). Examining a large sample of the population, the tendency to sensation-seeking was found to increase from age 12 years to 14 years and then steadily decline to age 24. The tendency to impulsivity declines gradually from age 12 to 22.

  Concerning the pursuit of rewards, two related questions are:

  1 Why is the period between childhood and adolescence one of increasing risk-taking?

  2 Why is the period between adolescence and adulthood one of decreasing risk-taking?

  The answers appear to lie in the profile of changes over the early years in the relative weights of excitatory (incentive-based) and inhibitory factors. The increase in strength of the dopamine-based incentive factor is such that inhibition does not keep up with it (Luciana and Collins, 2012). The rise of levels of sex hormones at puberty could strongly contribute to the strength of any sexual incentive, making this a likely time for attributing incentive salience to images taken from pornography (Owens et al., 2012). This maturation is thought to contribute to increased sensation-seeking between childhood and adolescence, followed by a levelling-off or decline beyond adolescence (Harden and Tucker-Drob, 2011). The lower-level systems are particularly sensitive to reward and novelty (‘sensation-seeking’) and their activation appears to give a bias towards relatively risky options with potentially high reward as opposed to more safe options (Casey and Jones, 2010; Steinberg, 2007). There is an increased level of dopamine activity at adolescence (Wahlstrom et al., 2010).

  There is slower maturation of the (‘high-level’) cognitive systems,1 which mediate more abstract reasoning, long-term planning and underlie restraint (Harden and Tucker-Drob, 2011). This would account for the decrease in impulsivity shown between childhood and adulthood. Of course, differences between individuals of the same age can be considerable and these might be associated with difference in the weight of levels of control.

  In evolution, a period of heightened exploration, sensation-seeking and risk-taking coinciding with sexual maturation might well have proven advantageous in, say, colonizing new territories, finding mates or earning status in a social hierarchy. This could have been especially so for boys, who are known to be more prone to risk-taking than are girls (Steinberg, 2008). By definition, novelty involves uncertainty and dopamine systems are particularly responsive to this, motivating engagement with sources of novelty and risk (Wahlstrom et al., 2010).

  High adolescent risk-taking is particularly likely to occur when being a member of a group (Steinberg, 2008). For example, whether an individual engages in sexual activity or takes alcohol or illegal drugs is strongly influenced by whether his or her peers do so. This might simply reflect the fact that adolescents spend more time in groups than others do, though this of course raises the issue of why they do this. Evidence suggests that the presence of adolescent peers increases tendencies to risk-taking by sensitizing the incentive-processing brain regions (Chein et al., 2011).

  Development, evolution and culture in understanding gender differences

  Consider the following interesting observation. Throughout the world, in most societies that have been examined, it is the broadly accepted cultural norm that men alone should be the ones who are permitted to take the initiative in making sexual advances (Ford and Beach, 1951). However, in reality and in defiance of such norms, for most of the cultures examined by Ford and Beach, girls and women do sometimes take the initiative in looking for sexual liaisons with men.

  The reasons that young people give for their first experience of sexual intercourse show a gender difference. Girls tend to express emotional and relationship reasons, whereas boys tend to express reasons of curiosity or lust (Hawes et al., 2010). A significant number attribute their first experience to peer pressure, often under the influence of alcohol. Social context appears to play a somewhat stronger influence in the initiation of girls’ sexual activity, whereas boys’ initiation can be better explained in terms of rising levels of testosterone (Udry, 1990).

  Evolutionary psychology explains gender differences in how sexual desire is expressed as the result of genetically influenced differences between males and females. There is a caution to be sounded here. These behavioural differences might reflect genetically determined sex differences in the processes underlying sexual desire. However, writers taking a feminist perspective argue that they might instead, or in addition, be the outcome of male attitudes to anything but a narrow range of acceptable female behaviour (Hrdy, 1981). It could be that there is some genetically determined tendency acting in the direction of a sex difference, but that this effect is strongly magnified by culture. So, how can this gender difference be explained?

  There could well be a biological basis to gender differences but any neat dichotomy needs qualification. Consider by analogy skin colour. Without doubt, this is largely genetically determined. However, imagine growing up in racially segregated society. Based upon this biological factor, a person is in effect allocated to one half of a binary divide: black or white. How that person is then treated depends upon cultural factors such as implicit assumptions, laws, economics, customs and prejudices. It is worth raising the issue that some o
f the differences in gender roles might similarly reflect social labelling, the label reflecting a biological difference. Furthermore, the individual could assume a self-identity based in part upon such social labelling.

  Comparing humans and other species

  The history of the application of evolutionary theory to the social sciences has not been a happy one. Social scientists of radical and progressive persuasion have tended to see evolutionary explanations as inevitably supporting the status quo and being male-centric. However, the Harvard anthropologist Sarah Blaffer Hrdy (Hrdy, 1999) is able to reconcile both evolutionary and cultural perspectives.

  Hrdy (1999, p. xxvi) asks:

  If our ancient female ancestors were not ‘naturally’ coy, sexually discreet, monandrous, and modest, then how did women in so many cultures become so sensitive to their social surroundings in that respect? Was the sexual modesty that to varying degrees characterizes women in all societies selected for some time in the Pleistocene2 because women lived longer if they learned to be sensitive to disapproval? Or did some transformation from a near absence of sexual inhibition (as in chimps and bonobos) evolve earlier or later? Why are women so modest compared with other primates? And within our own species, how much variation exists and why? Is modesty learned, or partly so? This is just one aspect of an ongoing debate over the nature of human nature.

  Observers of animal behaviour have tended traditionally to see sexual motivation in terms of males who are aggressive and active choosers, and who select from amongst passive or, at most, receptive females (Hrdy, 1999). However, according to Hrdy, careful observation of non-human primates does not lead to this conclusion.

  Hrdy nominates the Barbary macaque as the most ‘promiscuous’ of non-human primate females. Typically females of this species will mate at least once with every sexually mature male troop member, abandoning a male after each copulation, and, at her peak of fertility, copulating at around once every seventeen minutes. In most cases observed, the female took the initiative in securing these copulations. In some cases, females are particularly solicitous of mating, even at times when fertilization is impossible. Hrdy suggests that this points to a functional value of such mating.

  The evolutionary psychologist David Buss acknowledges that casual sexual encounters might have brought some advantages to women in terms of assessing the value of available males and her own value as well as negotiating access to a male’s resources, such as meat from a recent animal kill (Buss, 2003). Also, the male in question might serve as a kind of understudy in case the regular partner is deposed, killed or injured. Furthermore, the so-called ‘good genes hypothesis’ suggests that a female might secure genes from a particularly attractive male by means of a casual encounter, thereby involving a cuckolded partner. It appears that women tend to select men who are facially symmetrical for their affairs and hence likely to produce sexually attractive offspring. Anthropological evidence points to much greater degrees of female activity and promiscuity in societies where women have more power (Goethals, 1971).

  Gender differences in child rearing

  Some theorists attach weight to social learning (Chapter 13) in determining gender differences. Various processes underlie sex differences in learning and these include reward, punishment and observational learning (‘imitation’). Which behaviours are modelled depends upon a number of factors such as the power shown by the model and the consequences of the model’s actions. For example, aggression is more likely to be modelled if it has been observed to achieve favourable consequences.

  Evidence suggests that children learn socially approved sex-typed behaviours by means of both direct reinforcement of the sex-appropriate behaviour (e.g. by parental approval) and observing the behaviour of models that is followed by favourable consequences. Certain behaviour acquires negative connotations by verbal descriptions, such as sissy (for boys) or tough (for girls). An admission of anxiety is not considered manly and so is less likely to be shown by boys than it is by girls. Aggression fits the notion of sex-typing, with boys showing more physical aggression than do girls. Observations of parental behaviour reveal that boys are not discouraged from expressing aggression to the extent that girls are. Girls both show more dependency upon others than boys and are reinforced more by others for showing it. These could represent developmental precursors of later interactions with sexual desire and modes of expressing that desire.

  Sanctions against female sexuality

  Almost as a universal, there have been severe sanctions against female adultery, promiscuity or even sex before marriage, enforced by officers of the law and religion, male relatives and partners. In some cultures, this prohibition extends even to showing the face or an ankle in public. In the most extreme cases, women are subject to disfigurement of the genitals in order to deter sexual desire and girls judged not to be virgins at marriage are killed (Hrdy, 1981; Smuts, 1996). Sanctions against unacceptable male sexuality tend to be much milder, if they even exist.

  Surgical removal of the clitoris (‘clitoridectomy’) as a cure for masturbation appeared in England around 1858 but mercifully never became established. In the United States, this and other forms of genital mutilation, as well as removal of the ovaries, were not uncommonly prescribed as a cure for masturbation and survived to at least 1937 (Barker-Benfield, 1976; Moscucci, 1996).

  Why, as happens in parts of North Africa, should a man insist that any potential future wife would earlier have received genital mutilation? In some of the forms practised, it is easy to appreciate that this operation was perceived to guarantee her virginity and increase the chances of chastity and later fidelity, thereby increasing his certainty of paternity of any children. Indeed, her marital prospects required this. The belief prevailed that women would otherwise be over-sexed and promiscuous. The Chinese custom of binding the feet of girls appears to have emerged and survived for some thousand years for the same reason: immobility as a guarantee of virginity, chastity and fidelity and a passport to a good economic future (Mackie, 1996). As a bonus, bound feet were something of a fetish for Chinese men and were thought to lead to better sex.3

  All this, it is argued, has led the developing young woman to associate sex with danger and tends ‘to foster a kind of female sexuality that responds to male needs and desires rather than one that has needs and desires of its own’ (Smuts, 1996, p. 255). Consider the argument that, because of the dangers to women, a restrained sexual motivation has been favoured by evolution. There are several arguments against this (Hrdy, 1981; Smuts, 1996), including:

  If sexual desire is intrinsically weaker in females, why are such extreme measures taken to restrain it?

  There can be an important reproductive advantage gained by women having multiple partners.

  Non-human primates and women in societies with fewer ‘coercive constraints’ reveal excitation of female desire by variety.

  Barbara Smuts considers Symons’ argument that the relatively low numbers of partners of lesbians as compared to either gay or heterosexual males is evidence of the intrinsically weaker level of desire for novelty in women. She suggests that such women are not immune from an earlier, if not current, influence of male-dominated culture.

  Smuts (1996) suggests that (p. 254):

  human females are less promiscuous and appear to be less sexually motivated in part because of the effects of male aggression on female sexuality.

  This is such that (p. 255):

  in most societies, it is impossible to identify the ‘intrinsic’ nature of female sexuality based on female behaviour.

  Smuts (1992) adds that in some cultures female sexual adventure is more tolerated than in others (p. 30):

  I do not call attention to these considerations in order to argue that in the absence of constraints, female sexuality would be just like male sexuality. Rather, my goal is to emphasize the need to investigate how the experience and expression of female sexuality varies, at both the psychological and behavioural levels, depending on the extent
and nature of the constraining influence of male strategies. Until these investigations provide new evidence, the nature of female sexuality must remain an open question.

  Orgasm

  The function of female orgasm is a topic of much discussion (Chapter 10). It could help the woman to assess the viability of the male with whom she is copulating (Meston and Buss, 2009). The man who hangs around long enough to trigger orgasm might be a considerate and investing type!

  Sexual orientation

  Closely related to the subject of gender differences in sexuality is that of sexual orientation, similar arguments being raised by these topics. The question usually takes the form – is sexual orientation, whether heterosexual, homosexual, bisexual or asexual, determined either biologically or socially? This suggests an unrealistically neat dichotomy, as will be shown in this section. Differences between heterosexual and homosexual behaviour, of course, derive primarily from differences in the object (the ‘goal’) of sexual desire. This is both in terms of the individual’s desired partners and the content of his/her sexual fantasy (Bogaert, 2006; Storms, 1981).

  Biological perspectives

  The biological argument sometimes takes the form: does a gene (a ‘gay gene’) determine sexual orientation? A genetic contribution does not require that a single gene determines orientation. More likely, a combination of genes could yield a tendency to a particular orientation. Evidence derives from twin studies, comparing identical and fraternal twins (Hines, 2004). Research tentatively suggests that the ‘concordance’ (correlation) in orientation is closer in identical twins, who are genetically identical, than in fraternal twins. Attempts have been made to rule out the possible explanation that identical twins are treated in a more similar way than are fraternal twins.