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Human male sexuality

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Pair-bonded human male and female

Human male sexuality encompasses a wide variety of feelings and behaviors. Men's feelings of attraction may be caused by various physical and social traits of their potential partner. Men's sexual behavior can be affected by many factors, including evolved predispositions, individual personality, upbringing, and culture. While most men are heterosexual, significant minorities are homosexual or varying degrees of bisexual.

Contents

Sexual attractionEdit

Men's mate preferences for women can be based on both physical and non-physical factors. There is a great deal of cross-cultural similarity in men's preferences, but there are a few notable differences as well.

Physical attractivenessEdit

Signs of youth and health, such as clear, smooth skin, are universally regarded as attractive. Facial symmetry, femininity, and averageness are also linked with attractiveness.[1]

Men typically find female breasts attractive[1] and this holds true for a variety of cultures.[2][3][4]

 
A comparison of a desirable waist-to-hip ratio (0.7) and an undesirable waist-to-hip ratio (0.9).

Women with a relatively low waist-to-hip ratio (WHR) are considered more attractive. This appears to be universal across cultures, although exactly what WHR is preferred varies depending on the WHR of women in the local culture. In Western cultures, a WHR of 0.70 is preferred. Other possible physical factors are low body mass index, low waist circumference, longer legs, and greater lower back curvature.[1]

Preference for a slim or a plump body build is culturally variable, but in a predictable manner. In cultures where food is scarce, plumpness is associated with higher status and is more attractive, but the reverse is true in wealthy cultures.[1]

The exact degree to which physical appearance is considered important in selecting a long-term mate varies between cultures.[1]

Non-physical factorsEdit

Men desire partners who are intelligent, kind, understanding, and healthy, as do women.[1]

Men generally prefer their wives to be younger than they are, but by how much exactly varies between cultures. Older men prefer greater age differences, while teenage males actually prefer females somewhat older than they are.[1]

The importance of premarital chastity varies a great deal according to culture, but across cultures marital unfaithfulness is more upsetting to men than any other pain their wife could inflict.[1]

Sexual behaviorEdit

Many factors influence men's sexual behavior. These include evolved tendencies, such as a greater interest in casual sex, as well as individual and social factors related to upbringing, personality, and relationship status.

Interest in casual sexEdit

Compared to women, men have a greater interest in casual sex. On average, men express a greater desire for a variety of sex partners, let less time elapse before seeking sex, lower their standards dramatically when pursuing short-term mating, have more sexual fantasies and more fantasies involving a variety of sex partners, report having a higher sex drive, find cues to sexual exploitability to be attractive for short-term mating, experience more sexual regret over missed sexual opportunities, have a larger number of extramarital affairs, are more likely to seek hookups and friends with benefits, and visit prostitutes more often.[5]

Upbringing and personalityEdit

One study has several factors that influence the age of first sexual intercourse among both genders. Those from families with both parents present, from high socioeconomic backgrounds, who performed better at school, were more religious, who had higher parental expectations, and felt like their parents care, showed lower levels of sexual activity across all age groups in the study (age 13–18). In contrast, those with higher levels of body pride, showed higher levels of sexual activity.[6]

SociosexualityEdit

Males who are in a committed relationship have a restricted sociosexual orientation, and will have different sexual strategies compared to males who have an unrestricted sociosexual orientation. Males with a restricted sociosexual orientation will be less willing to have sex outside of their committed relationship and adjust their strategies according to their desire for commitment and emotional closeness with their partner.

Sociosexually restricted males are less likely to approach females who have lower waist-to-hip ratios (0.68–0.72), generally rated as more physically attractive.[7]

Expected parental investmentEdit

Elizabeth Cashdan[8] proposed that mate strategies among both genders differ depending on how much parental investment is expected of the male, and provided research support for her hypotheses. When men expect to provide a high level of parental investment, they will attempt to attract women by emphasising their ability to invest. In addition, men who expect to invest will be more likely to highlight their chastity and fidelity than men who expect not to invest. Men with the expectation of low parental investment will flaunt their sexuality to women. Cashdan argues the fact the research supports the idea that men expecting to invest emphasise their chastity and fidelity, which is a high cost strategy (because it lowers reproductive opportunities), suggests that that type of behaviour must be beneficial, or the behaviour would not have been selected.[8]

Paternity certaintyEdit

Sexual strategies are essential to males when pursuing a mate in order to maximize reproductive potential, in order for their genes to be passed on to future generations. However, in order for a male's sexual strategy to succeed with a female, it is the male who must compromise his own sexual strategies, typically because of uncertainty over the paternity of a child, whereas maternity is essentially certain.

Women have higher levels of parental investment because they carry the developing child, and higher confidence in their maternity since they witness giving birth to the child. Hence women have reason to accept greater responsibility for raising their children. By comparison, males have no objective way of being certain that the child they are raising is biologically theirs. Because of this difference, males have to adapt their own sexual strategies to accommodate the strategies of the females around them.[9]

Among other behaviors, this means that men are more likely to favour chastity in a woman, as this way a male can be more certain that her offspring are his own. Such a strategy is seen in males, and maternity is never doubted by the female, and so a chaste male is not highly valued by women.[citation needed] However, for men, female chastity confirms paternity, causing the male to compromise his sexual strategies in order to select a chaste mate.

Sexual coercion and violenceEdit

Sexual coercion is forcing mate choice against a partner's will or preference. Sexual coercion increases the chance of a female mating with a male, and decreases the chance that the female will mate with another male.[10] There are several methods by which sexual coercion occurs. These are harassment, intimidation, and forced copulation (rape).[11]

Evolutionary explanationsEdit

Thornhill and Palmer's A Natural History of Rape investigates the evolutionary causes of sexual coercion, particularly of rape, and suggests that such behaviour is a result of sexual selection, rather than Darwinian natural selection.[12]

Of ten listed hypotheses, they accepted two reasonable hypotheses:

  • The first, that rape is a by-product of an adaptation other than rape.
  • The second, that rape as an adaptation (the rape specific adaptation hypothesis), which suggests that rape evolved because it was an adaptive, beneficial behaviour in the environment of evolutionary adaptation.

Thornhill and Palmer argue that these two theories are the strongest of the ten for several reasons. For example, both hypothesis argue rape exists because it functions to increase matings, thus improving reproductive success. Because rape can be a costly behaviour for the male – he risks injury inflicted by the victim, or punishment by her social allies, it must have strong reproductive benefits for the behaviour to survive and be demonstrated today. Thornhill and Palmer also use several facts to support the idea that the two evolutionary based hypotheses are the most reasonable. They argue that the fact that most female rape victims are of childbearing age, that married women and women of childbearing age suffer more psychological distress after rape than single or postmenopausal women, and that rape takes place in a variety of other species, all point towards an evolutionary heritage for rape behaviour.[12]

Rape as an evolutionary by-product hypothesisEdit

The 'rape as a by-product' explanation holds that rape behaviour evolved as a by-product of other psychological adaptations in men to obtain many mates.[12] This adaptation not only leads to rape but a number of other behaviours including overrating female sexual interest,[13] a desire for sexual variety, coercion, and sexual arousal which is not dependent on the consent of mate.[12][14]

Rape as specific adaptation hypothesisEdit

The rape specific adaptation hypothesis suggests that rape is an evolved behaviour because it provides direct benefits to the rapist. In this case, the benefit would be a higher chance of reproductive success through increasing mate number. The hypothesis suggests that rape behaviour is the result of psychological mechanisms designed specifically to influence males to rape, unlike in the by-product hypothesis. This theory suggests that rape by a man which offers no chance of reproductive success, i.e. the rape of any other person who is not a female of reproductive age, is a maladaptive byproduct of this evolutionary adaptation.[12]

Support for the idea that rape provides males with a way to increase their reproductive success comes from a study by Barbaro and Shackelford, who found that men in committed heterosexual relationships who had committed at least one act of violence/coercion towards their partner in the last month had more in-pair copulations per week.[15]

Some potential specific psychological adaptations that Thornhill and Palmer suggest might be present in men to induce rape include the evolution of a mechanism that helps males evaluate the vulnerability of potential victims, or mechanism that motivates men with a lack of sexual access to females, to rape – the mate deprivation hypothesis.[12]

The mate deprivation hypothesis alludes to the concept that the threshold for rape is lowered in males that lack alternative reproductive options. This idea is supported by the fact that rape is disproportionately committed by men with a lower socioeconomic status.[16] However, Malamuth[17][18] found a relationship between low socioeconomic status and a rearing environment in which social relationships were not committed, which in turn resulted in a male's reduced ability to form enduring relationships in later life. This subsequently results in less alternative reproductive options. Therefore, while there is indeed a relationship between a lack of alternative reproductive options and rape behaviour, there are likely to be a number of co-morbid factors affecting this correlation, leading Thornhill and Palmer to conclude that the idea of a specific psychological adaptation that motivated men with a lack of sexual access to females is unlikely, and that further research need be conducted.

Rejected hypothesesEdit

One of Thornhill and Palmer's rejected hypotheses for why men rape implicates violent pornography. Subscribers to the social science theory of rape[19][20] purport that one of the main reasons why the human male learns to rape is via learning imitative behaviour when watching violent pornography. However, this fails to explain why if males are likely to imitate behaviour witnessed in violent pornography they would not also imitate the actions of human males in other videos. Furthermore, no explanation is offered into why this behaviour is inspired in some men and not others. It is also limited in its ability to predict valuable variables surrounding why rape occurs (such as who, when or where). For this reason, Thornhill and Palmer argued that "although the removal of violent pornography may be desirable in its own right, it is very unlikely to solve the problem of rape".[12]

Another of their rejected hypotheses is the 'choosing victim' rape-adaptation hypothesis which suggests that there is an evolved victim-preference mechanism to maximise the reproductive benefits of rape. This hypothesis suggests that men would be most likely to rape reproductive-age females. Research shows that the age of US rape victims correlates slightly better with age of peak fertility than age of peak reproductive potential.[16]

Evolutionary selection of sexual coercionEdit

Though it is a widely held view that sexually coercive behaviour occurs as a result of sexual selection, Smuts and Smuts (1993) proposed that sexual coercion is best described as a third type of sexual selection, rather than attempting to fit it into either of the other two forms: mate choice and intrasex competition.[10] While sexual coercion certainly interacts with the other two forms of sexual selection, its conceptual distinction lies under the fact that a sexually coercive male may succeed in the competition for mates using coercion, despite losing in male-male competition for females, and despite not being chosen by females as a mate.

Impact of upbringingEdit

Malamuth found that men raised in the absence of their father (or where resources were scarce) reported more use of sexual coercion in the past, and were more likely to indicate being more willing to rape, in the event that there was no chance of them getting caught.[17]

Male sexual entitlementEdit

Gender stereotypes view men and boys as being the more typically aggressive sex.[21] This can result in men being more likely than women to view pressuring a woman or girl into sex as acceptable behavior.[22] A study has shown that male sexual entitlement might be related to men's preference for larger breasts.[23] Another two studies have shown that some young English and Canadian students think that performing oral sex on women is demeaning.[24][25] Non-consensual condom removal has been described as "a threat to [a victim's] bodily agency and as a dignitary harm", and men who do this " justify their actions as a natural male instinct".[26]

Male sexual entitlement, which consequently can predict sexual entitlement due to societal norms, has been found to predict rape-related attitudes and behaviors.[27] If men feel that their own sexual needs are more important, it is likely that they will have rape-related attitudes, as such, attitudes reinforce their own sexual entitlement as being the more dominant sex.

HomosexualityEdit

Sexual orientationEdit

Sexual orientation refers to one's relative attraction to men, to women, or to both. Most researchers studying sexual orientation focus on patterns of attraction rather than behavior or identity, because culture affects the expression of behavior or identity and it is attraction that motivates behavior and identity, not the other way around.[28]

Aside from being heterosexual or homosexual, individuals can be any of varying degrees of bisexual.[28][29] Many researchers expect that in all cultures the vast majority of people are sexually predisposed exclusively to the other sex, with a minority being sexually predisposed to the same sex, whether exclusively or not.[28] In Western surveys, about 93% of men identify as completely heterosexual, 4% as mostly heterosexual, 0.5% as more evenly bisexual, 0.5% as mostly homosexual, and 2% as completely homosexual.[28][29] An analysis of 67 studies found that the lifetime prevalence of sex between men (regardless of orientation) was 3-5% for East Asia, 6-12% for South and South East Asia, 6-15% for Eastern Europe, and 6-20% for Latin America.[30] The World Health Organization estimates a worldwide prevalence of men who have sex with men between 3 and 16%.[31]

Sexual orientation can be measured via self-report or physiologically. Multiple physiological methods exist, including measurement of penile erection, viewing time, fMRI, and pupil dilation. In men, these all show a high degree of correlation with self-report measures,[28] including men who self report as "mostly straight" or "mostly gay."[29]

CausesEdit

Although no causal theory has yet gained widespread support, there is considerably more evidence supporting nonsocial causes of sexual orientation than social ones, especially for males. This evidence includes the cross-cultural correlation of homosexuality and childhood gender nonconformity, moderate genetic influences found in twin studies, evidence for prenatal hormonal effects on brain organization, the fraternal birth order effect, and the finding that in rare cases where infant males were raised as girls due to physical deformity, they nevertheless turned out attracted to females. Hypothesized social causes are supported by only weak evidence, distorted by numerous confounding factors.[28] Cross-cultural evidence also leans more toward non-social causes. Cultures that are very tolerant of homosexuality do not have significantly higher rates of it. Homosexual behavior is relatively common among boys in British single-sex boarding schools, but adult Britons who attended such schools are no more likely to engage in homosexual behavior than those who did not. In an extreme case, the Sambia ritually require their boys to engage in homosexual behavior during adolescence before they have any access to females, yet most of these boys become heterosexual.[32][33]

It is not fully understood why the genes for homosexuality, or allowing it to develop, whatever they may be, persist in the gene pool. One hypothesis involves kin selection, suggesting that homosexuals invest heavily enough in their relatives to offset the cost of not reproducing as much directly. This has not been supported by studies in Western cultures, but several studies in Samoa have found some support for this hypothesis. Another hypothesis involves sexually antagonistic genes, which cause homosexuality when expressed in males but increase reproduction when expressed in females. Studies in both Western and non-Western cultures have found support for this hypothesis.[28][1]

Possible adaptive functionEdit

 
Pederastic courtship. Paris, Musée du Louvre.

Due to its existence in diverse cultures and through history, some researchers have argued that homosexual behavior has an adaptive function related to same-sex affiliation or alliance formation. Frank Muscarella argued that homoeroticism serves an indirect adaptive purpose, though this disposition would vary genetically among individuals.[34] R.C. Kirkpatrick similarly argued that homosexual behavior may be a type of reciprocal altruism or resource exchange, facilitating same-sex alliance formation, and that sexualization of these alliances occurs more often when competition for partners is especially severe.[35] They stated homosexual behavior helped reduce aggression between males, facilitated same-sex affiliation and alliance formation, and that it often occurred between males with a significant age or status difference. These relationships may have brought many benefits to the younger males, such as access to food, protection from aggression, greater status, and access to females. They point to the historical record for support, including examples such as pederasty in ancient Greece.

A 2014 study sought to test this affiliation hypothesis among 56 undergraduate men, and found that men in an affiliative priming condition are less averse to engaging in homoerotic behavior, with the effect most pronounced in men with high progesterone, a hormone associated with affiliative motivation. This group had a mean of 1.79 on their homoerotic motivation score (5 questions on a 5-point Likert scale) with scores of 1 indicating they "strongly disagree" they have interest in homosexual activity.[36]

CriticismEdit

Evolutionary psychologist David Buss criticized the alliance hypothesis. He argued it faces several empirical difficulties. He states that there is no evidence that most young men in most cultures use homoerotic behavior to establish alliances; instead, the norm is for same-sex alliances to not be accompanied by any sexual activity. Additionally, he states that there is no evidence that men who engage in homoerotic behavior do better than other men at forming alliances or ascending in status.[1]

Criticism from other researchers has been on various grounds. They have commented that the cultural data on sexual practices are sketchy and uneven; that there is no need to assume that homosexual behavior, more than any other sexual behavior, is under direct selection rather than being a neutral byproduct; that the hypothesis ignores the existence of sexual orientation; that it contradicts findings that behaviorally homosexual or bisexual men have much lower rates of fatherhood; that there is no evidence that men with bisexual experience have higher evolutionary fitness or are better than heterosexual men at forming same-sex alliances; that it does not account for the preponderance of nonsexual alliance formation; that primate homosexual behavior is not a uniform phenomenon and varies within and across species; and that since same-sex sexual partners are chosen on the basis of sexual emotion (in contrast to bonobos, for example), useful alliances of this kind would only occur as often as mutual sexual attraction, and such variability would seem to indicate a lack of design by natural selection.[37]

Sexual identityEdit

What impact same-sex sexuality has upon one's social identity varies across cultures. The question of precisely how cultures through history conceptualized homosexual desire and behavior is a matter of some debate.[38][39]

In Western cultures, sexual identity is defined based on the sex of one's partner. In some parts of the world, however, sexuality is often defined based on sexual roles, whether one is a penetrator or is penetrated.[31][40]

See alsoEdit

ReferencesEdit

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