Sexual Orientation and Sexuality - Sexuality, Relationships, and Work

The Psychology of Sex and Gender - Jennifer Katherine Bosson, Joseph Alan Vandello, Camille E. Buckner 2022

Sexual Orientation and Sexuality
Sexuality, Relationships, and Work

Singer-songwriter and actress Janelle Monáe.

Source: Erik Pendzich / Alamy Stock Photo

Test Your Knowledge: True or False?

· 9.1 Less than 5% of the U.S. population identifies as exclusively gay or lesbian.

· 9.2 Many asexual people report difficulty in understanding their internal experiences of their sexuality because they lack the language to describe these experiences.

· 9.3 Recent evidence suggests that most American children and teenagers have either sent or received sexts (sexual texts, images, or videos) via mobile phone.

· 9.4 Genital reconstructive surgery typically makes it difficult for transgender people to have orgasms.

· 9.5 While men experience their sexual peak between the ages of 19 and 25, women reach their sexual peak around the ages of 30—35.


How Do Understandings of Sexuality and Sexual Orientation Differ Across Time and Culture?

· Journey of Research: Sexual Orientation Change Efforts

What Is Sexual Orientation?

· Sexual Identity

· Motivation: Desire and Love

· Sexual Behavior

· Complexity of Sexual Orientation

How Does Sexual Orientation Develop?

· Phase Models of Sexual Identity Development

· Milestone and Narrative Models of Sexual Minority Identity Development

Why Do People Differ in Sexual Orientation?

· Biological Theories

· Evolutionary Theories

· The Integrative Approach

· Evaluation of Theories

How Do Sex and Gender Contribute to the Experience of Sexuality?

· Sexual Behavior, Attitudes, and Brain Activity

· Debate: Do Men Have a Stronger Sex Drive Than Women?

· Orgasm Frequency and Sexual Satisfaction

· Sexual Fluidity

How Does Sexuality Change Over the Life Course?

· Sexual Trajectories

· The Medicalization of Sexual Changes


Students who read this chapter should be able to do the following:

· 9.1 Locate current understandings of sexuality and sexual orientation within social, cultural, and historical contexts.

· 9.2 Describe the multiple dimensions of sexual orientation, and analyze different models of sexual identity development.

· 9.3 Evaluate biological, evolutionary, and integrative theories of sexual orientation.

· 9.4 Explain sex differences in sexuality, including attitudes and behaviors, orgasms and sexual satisfaction, and sexual fluidity.

· 9.5 Understand issues in sexuality across the life course, such as sexual peaks and the medicalization of sexual changes.


In 2016, charismatic young YouTube star Ricky Dillon released a video in which he came out about his sexuality to his 3.2 million curious viewers. Dillon explained that he had tried dating both women and men but never felt sexually attracted to anyone; therefore, he had come to realize that he was asexual. Then, in 2019, Dillon explained in another video that he no longer fully identifies as asexual, because he occasionally develops crushes on people. With his characteristic, good-natured humor, the 26-year-old called himself “the oldest virgin on YouTube” and admitted that he is still figuring himself out. The years since 2016 have seen other notable coming-out confessions by celebrities whose sexuality does not fit cleanly into the three-category, straight/gay/bisexual system. Actress and singer-songwriter Janelle Monáe described herself as “a queer black woman” in a 2018 interview, explaining that she has had relationships with both women and men and identifies with both bisexuality and pansexuality (Spanos, 2018). That same year, Brendon Urie, lead singer of Panic! At the Disco, called himself pansexual, explaining that he is happily married to a woman but often finds men attractive (Hazlehurst, 2018).

These diverse ways of experiencing sexuality are not new. And yet, labels such as “asexual” and “pansexual” are relatively new ways of describing sexual orientations. For many years, researchers and media sources have relied solely on the labels “straight,” “gay,” and “bisexual” to describe the full range of human sexualities. As we will convey in this chapter, this three-category system is overly simplistic and inadequate for capturing something as complex as human sexual orientation.

So, what is sexual orientation? Sexual orientation is an enduring pattern of cognitive, motivational, and behavioral tendencies that regulates the experience and expression of sexuality, which is the capacity for sexual responses and experiences. Thus, sexual orientation describes not only the sex(es) of the persons toward whom individuals direct their romantic and sexual feelings but also the self-labels they adopt and the sexual behavior they enact. As you will learn, a combination of genetic, neurological, hormonal, and sociocultural factors shapes the development and experience of sexual orientation.

In this chapter, we offer a broad overview of the concept of sexual orientation, from its historical origins in 19th-century Western medicine to current ways of thinking about it. Along the way, we also address the complexity of sexual orientation, including coverage of the most updated knowledge of what it is, why people differ on it, and how it develops. The second half of the chapter considers how sex and gender relate to sexuality and how people’s experiences of their sexuality change over the life course.

Sexual orientation An enduring pattern of cognitive, motivational, and behavioral tendencies that shapes how people experience and express their sexuality; often framed as the sex or sexes toward whom an individual feels attraction.

Sexuality The capacity for sexual responses and experiences.

Before we proceed, we note that sexual orientation is typically defined in a way that reinforces the sex and gender binaries. Thinking or talking about sexual orientation often involves assumptions that the world consists of people who are either female or male and that our sexuality orients us toward one or both of these sexes. Therefore, much of this chapter uses the sex binary as a framework. However, not everyone experiences sexuality in this manner. When possible, we draw your attention to alternative ways of experiencing sexuality that do not involve carving the world into female and male. In this spirit, consider this quotation from gender researcher Sandra Bem (1993):

Although some of the (very few) individuals to whom I have been attracted … have been men and some have been women, what those individuals have in common has nothing to do with either their biological sex or mine—from which I conclude, not that I am attracted to both sexes, but that my sexuality is organized around dimensions other than sex. (p. vii)


The idea that people have a stable, internal drive that orients them, sexually, toward members of a particular sex emerged relatively recently from Western cultures. The earliest known references to sexual orientation appeared in a letter written by the Hungarian journalist Karl-Maria Kertbeny in the late 1860s (Fone, 2000). Kertbeny used the word Homosexualität to describe erotic desire toward persons of the same sex and the word Normalsexualität to describe erotic desire toward persons of the other sex (note that the normal in Normalsexualität was not meant as a morality judgment, but merely signified that this was the more common form of desire). In English-language texts, the word homosexual was first used in 1892 by American psychiatrist James Kiernan, who defined “a homosexual” as an individual whose “general mental state is that of the opposite sex.” By the 1930s, both homosexuality and heterosexuality were used widely.


While homosexual and homosexuality are commonly used terms, some people find them offensive because they emerged from and reflect a historical time that fiercely pathologized same-sex sexuality. For this reason, we use these terms sparingly throughout this book. We generally prefer the terms same-sex sexuality, members of the LGB community, or sexual minority individuals. As you may remember from Chapter 1, sexual minority individuals are those who identify with any nonheterosexual orientation.

These early references to heterosexuality and homosexuality reflected a new way of thinking about sexuality. Whereas people have always experienced varying forms of sexuality, it did not become popular to classify people into groups based on the sex of their desired partners until the 1860s. This new labeling did more than create categories of sexuality types; it shifted how people thought about sexuality. Prior to the mid-1800s, people enacted all sorts of sexual behavior, but they did not internalize sexuality as part of their identity the way people do today. Thus, humans’ understanding of our own propensity for sexuality has changed over time and may continue to change as cultural values shift and awareness of diversity increases.


To the extent that sexual orientation guides people’s attractions to specific types of people, are those attractions based more on other people’s sex or on their gender identity? Because most people are cisgender, their sex and gender identity are the same. But what about transgender, genderqueer, or nonbinary individuals? Suppose you were a cisgender man in a relationship with a transwoman. Would you consider yourself straight (because your partner identifies as a woman) or gay (because your partner was assigned male at birth)? Why? What are some limitations of thinking about sexual orientation solely in terms of the straight/gay binary?

Prior to the mid-1800s, to the extent that members of Western cultures made assumptions about people’s sexuality, these pertained to the specific sexual acts or roles (e.g., penetrative versus receptive) that people performed rather than the sex(es) of the partners that people preferred. In ancient Greece, for example, adult men and adolescent boys commonly formed temporary same-sex couplings, or pederastic relationships, in which men offered education, socialization, and protection in exchange for sexual favors from their younger partners (Tskhay & Rule, 2015). In such pairings, meaning was derived not from either man’s assumed orientation toward same-sex partners, but instead from the sexual role played by each partner, with the penetrative role conveying maturity and higher social status and the receptive role conveying youth and lower social status (Fone, 2000).

Detail from an ancient Greek fresco depicting an adult man (at right) and his younger male lover (at left). From the Tomb of the Diver, Paestum, Italy, circa 480 BC.

Source: ©

Similarly, in non-Western cultures, sexual behavior often has meanings that have little to do with sexual orientation. Consider the Sambian people of Papua New Guinea. In this culture, pubescent boys undergo a manhood ritual that involves fellating and ingesting the semen of adult male tribe members (Tskhay & Rule, 2015). Sambian people believe that only through ingesting semen can boys gain the strength and bravery to become warriors, and once they have transitioned to manhood, they largely maintain heterosexual relationships. This cultural practice is not thought to reflect same-sex desire but rather gender role socialization.

Why did people’s thinking about sexual orientation change? Some scholars propose that 19th-century Western medical and scientific fields developed the idea of sexual orientation as a means of controlling people’s erotic behavior (Foucault, 1978). Categorizing and labeling sexuality gave scientific credibility to the notion that some kinds of sexual attractions were “natural” and “normal,” whereas others were “deviant.” This position was reflected in the longstanding practice of psychologists and psychiatrists to treat homosexuality as a mental disorder, which persisted until the early 1970s (Hancock & Greenspan, 2010; for more on this, see the “Journey of Research”). Regardless of why people started to label distinct sexual orientations, the tendency to do so remains popular today, although cultures vary widely in the labels and meanings that they give to different sexual orientations.


Sexual orientation change efforts (SOCEs; sometimes called conversion therapies) have a controversial and troubling history within psychology. In the late 19th century, Sigmund Freud and his daughter Anna treated gay and lesbian clients who wished to change their sexual orientation, although Freud was skeptical about the likely success of this treatment: “To undertake to convert a fully developed homosexual into a heterosexual is not much more promising than to do the reverse” (Freud, 1920, p. 129).

What does the research say about the outcomes of SOCEs? Some early accounts portrayed them as modestly effective. In 1962, Irving Bieber reported on the results of psychoanalysis with 106 gay men, concluding that 27% of them shifted to exclusive heterosexuality following treatment (Bieber et al., 1962). Over the next decades, other psychoanalysts reported rates of “success,” which they defined as a change to exclusive heterosexuality, ranging from 18% to 44% (Throckmorton, 1998). However, the clients most likely to report changes in sexual orientation were those who were strongly motivated to change and who had prior histories of heterosexual experiences or leanings. This raised questions about the generalizability of the findings.

From the 1960s to the 1980s, research examined the effectiveness of behaviorism-based SOCEs, which often used aversion therapy to condition gay male clients to associate sexual stimuli (such as images of attractive nude men) with pain, nausea, or negative mental imagery (M. P. Feldman, MacCulloch, & Orford, 1971). Other behavioral methods included assertiveness training or reinforcement of heterosexual behaviors (Greenspoon & Lamal, 1987). Again, mixed findings emerged, with reports of conversion to heterosexuality ranging from 0% to 65%.

Comparatively little systematic research examines the effectiveness of SOCEs that use cognitive therapy, group therapy, or religion-based approaches (Haldeman, 1994). The existing research in these areas often relies on single case studies or very small samples, and the same individuals who conduct the therapy also interpret and report the results, raising the possibility of observer bias. Moreover, almost all of the evidence regarding the effectiveness of SOCEs relies on self-reports by clients, many of whom are strongly motivated to pursue a heterosexual life for religious or cultural reasons. People who want to change might claim that their treatment was effective because they feel pressure to deny their true leanings.

In 1973, the American Psychiatric Association declassified same-sex sexuality as a psychological disorder, and shortly thereafter, the American Psychological Association (APA) urged “all mental health professionals to take the lead in removing the stigma of mental illness that has long been associated with homosexual orientations” (Conger, 1975, p. 633). Given that same-sex sexuality was no longer considered a disorder, it became professionally unethical to conduct SOCEs, so research on their effectiveness declined (APA, 2009a). Though religion-based SOCEs remain prevalent, the people who conduct these therapies often lack professional training in psychology and do not follow the ethical codes of the APA. Further, when conducted with minors against their will, religion-based SOCEs may harm their recipients by increasing the risk of depression, anxiety, drug use, and suicide (Human Rights Campaign, 2017).

To offer a conclusive answer about the effectiveness of SOCEs, an APA task force conducted a systematic review of 83 published, peer-reviewed studies on SOCEs in the mid-2000s (APA, 2009a). The task force determined that SOCEs do not effectively reduce same-sex attraction or behavior or increase other-sex attraction or behavior. Moreover, many people suffer harm from SOCEs. Given these outcomes, the task force strongly opposed the use of SOCEs. Most major medical and psychological organizations, including the World Health Organization, the American Medical Association, and the American Academy of Pediatrics, similarly discredit the effectiveness of SOCEs and take official positions against their practice. As of 2019, 18 U.S. states have banned the use of SOCEs on minors by licensed mental health providers, and bills have been introduced in both the Senate and the House of Representatives to ban the use of any SOCEs in the United States (Riley, 2019). However, since they are privately operated and difficult to regulate legally, religion-based SOCEs are still practiced on vulnerable sexual minority youth today.


Since the earliest origins of the concept of sexual orientation, different scholars have offered different definitions of it. As we discussed earlier, James Kiernan defined same-sex sexuality in terms of an individual’s “mental state,” implying that sexual orientation is a psychological phenomenon. Almost 60 years later, Alfred Kinsey defined sexual orientation in terms of both sexual feelings and sexual experiences, thus adding a behavioral component to the definition (Kinsey, Pomeroy, & Martin, 1948). Others propose even more complex definitions. Herek (2000), for instance, lists five dimensions of sexual orientation, including sexual attraction, sexual behavior, personal identity, romantic relationships, and community membership. Given the complexity of sexual orientation, people do not necessarily agree about how best to define it. Here, we talk about three primary dimensions of sexual orientation: identity, motivation, and behavior.

Sexual identity The label that people use to describe their sexual orientation and their emotional reactions toward this label.

Sexual Identity

Identity refers to one’s recognition of the self as belonging to a given social group or category, along with the emotional significance that one attaches to this group membership. Thus, sexual identity refers to both the label that people use to describe their sexual orientation and the emotional reactions that they have to this label. Most people use the terms that we have already encountered in this chapter, including heterosexual or straight, lesbian, gay, and bisexual. How frequently are these sexual identities represented in the population? Using probability sampling, Laumann and his colleagues found that 2.0% of men identified as gay, 0.9% of women identified as lesbian, and 0.8% of men and 0.5% of women identified as bisexual. The remainder (97.2% of men and 98.6% of women) identified as heterosexual (Laumann, Gagnon, Michael, & Michaels, 1994). Herbenick et al. (2010) found comparable numbers over a decade later, with 4.2% of men and 0.9% of women identifying as gay or lesbian, 2.6% of men and 3.6% of women identifying as bisexual, 92.2% of men and 93.2% of women identifying as heterosexual, and 1.0% of men and 2.3% of women selecting “other.” Based on the results of probability sampling studies like these, Bailey et al. (2016) concluded that fewer than 5% of individuals in Western cultures experience predominantly same-sex attractions, and this rate appears to be stable over time and culture.

What about the small percentage of people who describe their sexual orientation as “other”? Perhaps these are people like Ricky Dillon, Janelle Monáe, and Brendon Urie, who do not fit into the sexual orientation categories that usually appear on surveys. Recall from the chapter opener that Dillon identified as asexual, meaning that he lacked sexual interest in other people. In a large, national probability survey of British residents, Anthony Bogaert found that 1% of respondents indicated never having felt sexual attraction to another person (Bogaert, 2004). Asexual individuals may still experience romantic love, however, and some engage in sexual activity with partners despite their lack of sexual interest. Others, who identify as aromantic, lack all romantic interest in others. Perhaps Dillon’s confession that he lacks sexual attraction, but still develops crushes, indicates that he is asexual but not aromantic. In contrast, Monáe and Urie both identify as pansexual, meaning that they experience romantic or sexual attractions to people of all sexes and gender identities.

Once people categorize themselves into a given social group, they tend to incorporate the traits, behaviors, and values associated with this group into their self-concept (J. C. Turner, Hogg, Oakes, Reicher, & Wetherell, 1987). Thus, people often come to view themselves as similar to other members of their sexual orientation group and as sharing similar experiences and outcomes. Accordingly, many people view their sexual identity as a central and important part of themselves and associate it with positive feelings. There are exceptions to this, however. Given the stigmatization and prejudice that sexual minority individuals face in many cultures, some experience negative, shameful, or fearful emotions associated with their sexual identity. For example, some Latino gay men who are raised with values of familism—viewing the family as central and prioritizing family over self—report experiencing feelings of regret, sadness, and conflict surrounding their sexual identity if relatives interpret their same-sex sexuality as a family betrayal (A. A. Eaton & Rios, 2017). Some sexual minority individuals also experience internalized homophobia, meaning that they internalize the negative messages they receive about same-sex sexuality from the larger culture. People higher in internalized homophobia tend to feel less positive about their sexual identity and less connected to other LGB individuals (Szymanski, Kashubeck-West, & Meyer, 2008).

Finally, some people do not identify with a sexual orientation label at all. Some may avoid labels due to uncertainty about which one best applies to them. Others may consider themselves fluid, meaning that their sexual orientation changes over time, or they may view sexual identity labels as overly simplistic. Still others may avoid labeling themselves because they do not consider their sexuality a core feature of the self that connects them to a social group. In an upcoming section, we will go into more detail about the phases that characterize the development of sexual identity (see “How Does Sexual Orientation Develop?”).


What’s the association between status as transgender (vs. cisgender) and sexual orientation? As we discussed in Chapter 5, stereotypes of transgender people include the trait “gay,” indicating a widespread assumption that transgender people also experience same-sex sexuality. What do the data say? Jacobson and Joel (2019) asked a large, online sample of cisgender, transgender, and gender-diverse (e.g., nonbinary, genderqueer) adults about their internal experience of gender identity as well as their sexual attraction to women and men. Findings revealed that having a transgender or gender-diverse identity was very weakly correlated with nonheterosexual orientation, and that the variance in people’s sexual attractions to women and men was larger within each gender identity group than it was between the groups. This indicates that gender identity and sexual attraction are experienced as different things.

Motivation: Desire and Love

People experience the motivation components of sexual orientation as feelings of desire and love, both of which consist of longing for and impulse to seek proximity to a given target. Evolutionary theorists describe desire (lust) and love (attachment) as distinct but overlapping systems that regulate reproduction and mating (H. E. Fisher, 1998; Hazan & Zeifman, 1994). Although desire and love are often directed toward the same partner or person, they do not need to be. Moreover, each of them can be directed toward persons of the same or another sex, which means that a person may feel sexual desire primarily toward persons of the other sex while typically falling in love with persons of the same sex. Below, we consider these motivations in turn (see Table 9.1 for a summary).

Sexual desire (lust)—or a yearning to engage in sexual activities—is characterized by physiological arousal and regulated by gonadal hormones (estrogens and androgens) and neurotransmitters, including oxytocin (Diamond, 2003). For most people, sexual desire is directed primarily or exclusively toward other-sex persons, which is adaptive from an evolutionary standpoint because it motivates the sexual activity essential for reproduction (H. E. Fisher, 1998). Nonetheless, same-sex sexual desire can and often does coexist with other-sex sexual desires without impeding reproductive success (Diamond, 2003).

Sexual desire (lust) A wish or urge to engage in sexual activities.

Love (attachment) Strong feelings of affection and attachment that go beyond mere warmth.

Sexual desire may motivate people to seek out sexual union, but love presumably motivates people to direct their attentions toward a specific other person who is cherished above others. Love (attachment) consists of strong feelings of affection and attachment that go beyond mere warmth. The early stage of love (sometimes called passionate love) consists of arousal, urgent longing, exhilaration, and obsessive thinking about the love object. Such feelings are associated with elevated levels of neurotransmitters, including dopamine (which regulates feelings of reward and positive arousal) and norepinephrine (which plays a role in sympathetic arousal and the “fight-or-flight” response; Bartels & Zeki, 2000). The later stages of love (sometimes called companionate love) consist of calm, warm, and emotionally close feelings of intimacy toward a familiar other. Oxytocin and vasopressin, a neuropeptide related to intimacy and bonding, regulate this type of love (Carter, DeVries, & Getz, 1995).

Table 9.1

Evolutionary theorists view desire and love as part of larger behavioral systems that regulate mating, reproduction, and parenting. As you can see, these systems are associated with specific goals, feelings, behaviors, and neurological substances.

Passionate love An early stage of love characterized by arousal, urgent longing, and exhilaration.

Dopamine A neurotransmitter that is associated with feelings of reward, positive arousal, and intentional control of voluntary movement.

Norepinephrine A neuropeptide that is associated with sympathetic arousal and the “fight-or-flight” response.

According to evolutionary approaches, love (attachment) is adaptive because it encourages individuals to focus their mating efforts on a specific, preferred love object for the purpose of raising offspring. More specifically, love is presumably part of the mammalian pair-bonding system, which is the tendency for (usually) two adults to bond together, produce offspring, and coparent (Hazan & Shaver, 1994). Bonding and coparenting may have been especially important in humans’ evolutionary past, because human infants are vulnerable at birth and thus highly dependent on extended caregiving by willing adults. For example, human infants cannot hunt or prepare their own food, escape from predators, seek shelter and safety, or perform many other survival-relevant acts that infants of other species can do shortly after birth. Human infants also wean (stop nursing) at much younger ages than members of many other primate species, which means that human adults can have babies at relatively short intervals. As a result, humans can have multiple, highly dependent offspring at the same time, a challenge that some argue is best met through biparental care, or consistent and reliable parenting by two adults who coordinate activities and pool resources (Pillsworth & Haselton, 2005). Love may thus motivate adult mates to remain together in biparental units for long enough to see their offspring through a vulnerable infancy and childhood. Feelings of love would make it difficult, after all, to leave one’s family in search of other options. Note, however, that biparental care need not be provided by parents of different sexes, as any adults can work together to raise offspring. Moreover, some take issue with the suggestion that children need two parents to thrive, noting that single parents—with the right personal and structural resources in place—can successfully raise healthy and well-adjusted children (Howard & Reeves, 2014). We will return to this issue in Chapter 10 (“Interpersonal Relationships”).

Companionate love A later stage of love characterized by calm feelings of warmth and emotional closeness.

Pair-bonding system A system in which two adult members of a species remain bonded to one another for the purpose of producing and raising offspring.

Sexual Behavior

Sexual behavior includes anything that can be considered an erotic act, including behavior performed alone (e.g., masturbation and viewing of pornography) or with others (e.g., vaginal, anal, and oral sex), as well as acts performed with others who are not physically present (e.g., cybersex and sexting). So, what exactly do people do sexually, and with whom do they do it? As you might imagine, sexual behavior can be difficult to measure accurately because many people consider it extremely private. Still, we can get a rough look at the relative rates of various sexual behaviors by using random sampling techniques. In one nationally representative sample of over 5,800 U.S. adults, solo masturbation and vaginal intercourse were the most frequent sexual behaviors reported, with 62% of men and 39% of women reporting masturbation in the past month and 59% of men and 58% of women reporting vaginal intercourse in the past month (Herbenick et al., 2010). All other behaviors measured, including partnered masturbation, oral sex, and anal sex, were reported relatively less frequently by adults in this age range.

Unlike humans, baby sea turtles can run, seek safety, and find food as soon as they hatch from their eggs. They do not need parents to assist them, and it’s a good thing, too—sea turtle moms leave their babies before the babies even hatch.

Source: ©

Individuals report same-sex sexual activity less frequently than other-sex sexual activity. For example, whereas 86% of men ages 18—59 reported having vaginal sex at least once in their lifetime, only 8% reported experiencing receptive anal sex (penetrative anal sex with another man was not measured in this study), and 10%—11% reported oral sex with a man (Herbenick et al., 2010). Among women, while 91% reported having had vaginal sex during their lifetime, only 10%—12% reported having oral sex with a woman. In a more recent nationally representative study of sexual activity in the past year, 74% of men and 67.2% of women reported only other-sex partners, 4.4% of men and 2.9% of women reported only same-sex partners, and 1.3% of men and 1.0% of women reported both male and female partners, with the remainder reporting no sexual activity (Fu et al., 2019).

What about rates of same-sex sexual behavior in non-Western cultures? In a classic anthropological investigation of 76 predominantly non-Western societies around the world, Ford and Beach (1951) documented male—male sexual behavior in 64% of the societies and female—female sexual behavior in 22% of the societies. Broude and Greene (1976) reviewed ethnographic data collected in 69 non-Western cultures and found evidence of same-sex sexual behavior in 41% of them. Note, however, that Western influences may have altered expressions of same-sex sexuality in non-Western cultures. For example, European and American colonialization transmitted religious notions of stigma associated with same-sex sexual behavior to many indigenous people in Native American, South American, and African cultures (Tskhay & Rule, 2015). To this day, same-sex sexuality is illegal—and sometimes punishable by death—in parts of the Caribbean, Middle East, Africa, and Asia (Bailey et al., 2016). Taken as a whole, these data suggest that same-sex behavior, while rarer than male—female sexual behavior, is likely not limited to any particular type of culture, although cultural factors play a role in shaping its expression and consequences.


While evolutionary theory offers a framework for making sense of purportedly universal behavioral patterns, such as pair bonding, exceptions to pair bonding are found in every human culture. For instance, more U.S. families are now headed by single parents than ever before. Can evolutionary theory explain this change in the traditional family structure? If so, how? If not, what implications does this have for the explanatory power of evolutionary theory?

Some scholars propose that exposure to Western ideas, norms, and attitudes can have an impact on the sexual behaviors of people in non-Western societies more generally, not just in terms of same-sex sexuality. One large-scale survey in Thailand showed substantial differences in sexual behaviors as a function of rapid urbanization (Techasrivichien et al., 2016). Younger respondents, compared with older generations, reported engaging in sexual activity at a younger age, had sex with more partners, and had more sexual intercourse outside of marriage. Among the older generations, men consistently displayed more permissive sexual behavior (e.g., more sex partners and more sex outside marriage) than women, but these sex differences shrank substantially or disappeared among the younger respondents. This suggests that exposure to urbanization corresponded with reductions in sexual double standards (norms that allow greater sexual freedom in men than in women).

Sexting Sending or receiving sexual texts, images, or videos via mobile devices.

In recent years, researchers have become interested in the prevalence of sexting, defined as sending or receiving sexual texts, images, or videos via mobile devices. Because so many youths have mobile phones, some parents and educators worry that young people may be exposed to sexting before they are emotionally ready. One study sampled over 1,000 Internet users between the ages of 10 and 17 and found relatively low rates of sexting, with 2.5% of children reporting sending sexts and 7.1% reporting receiving sexts (Mitchell, Finkelhor, Jones, & Wolak, 2012). However, a review of 31 studies of mostly U.S. respondents found somewhat higher sexting rates, with approximately 10%—12% of adolescents (aged 10—17) sending sexts and 16% receiving sexts (Klettke, Hallford, & Mellor, 2014). In contrast, sexting rates were substantially higher among adults (aged 18—30), with about 49%—53% sending sexts and about 33% receiving sexts.

Complexity of Sexual Orientation

Why distinguish between identity, motivation, and behavior when defining sexual orientation? When researchers analyze these dimensions separately, it becomes apparent that people do not always experience their sexual orientation in a unified manner, with all of the dimensions lining up consistently. Consider the following findings from Fu and colleagues’ (2019) nationally representative study of U.S. adults: Among men who label themselves heterosexual, 1.6% are sexually attracted to men only. Among men who label themselves gay, 3.8% had sex with both women and men in the past year. Similarly, among women who label themselves heterosexual, 3.7% are sexually attracted to both women and men. Among women who label themselves lesbian, 13% had sex with both women and men in the past year. And of men and women who label themselves bisexual, 6%—8% are attracted only to women, while 3%—5% had sex only with men in the past year.

The list of examples goes on, with small numbers of people reporting these inconsistencies among their sexual orientation label (identity), desire (motivation), and behavior. This means that some heterosexual-identified people feel same-sex desire without acting on it, while others experience same-sex sexual behavior without adopting a same-sex sexual identity. And some gay-, lesbian-, and bisexual-identified people report (a) same-sex desire without same-sex behavior, (b) other-sex behavior with or without other-sex desire, or (c) some other combination of desire and behavior. Although the number of people who experience these inconsistencies is small, it appears stable over time: Fu et al. (2019) and Laumann et al. (1994) reported comparable numbers of people with these inconsistencies in their studies conducted 25 years apart.

To examine the complexity of sexual orientation further, Christine Kaestle (2019) recently examined changes over time in a nationally representative sample of 6,864 young Americans from adolescence through their late 20s. At four different times, participants reported on their sexual identity label (from options such as heterosexual, gay/lesbian, bisexual, and not attracted to either sex), attractions to both women and men, and recent romantic and sexual relationships. Kaestle found evidence of four classes of sexual orientations among men and five classes of sexual orientations among women, each characterized by unique and specific patterns of identity, desire, and behavior (these are summarized in Table 9.2). Finally, Lisa Diamond finds evidence for sexual orientation subtypes that reflect the fluidity versus stability of the identity rather than the sex or gender of the people toward whom attraction is directed, such as distinctions between stable lesbians, fluid lesbians, fluid bisexual women, and unlabeled bisexual women (L. M. Diamond, 2005, 2008). These analyses highlight the need for more nuanced understandings of sexual orientation that go beyond a simple, three-category system.

Table 9.2

Source: Based on data reported in Kaestle (2019).


How do you think researchers should define sexual orientation? Should they rely on people’s self-labels alone? Or should they consider people’s behaviors or desires? Does one of these aspects more clearly represent sexual orientation than the others? Should researchers measure all of them? Why or why not?


Given the complexity of sexual orientation, how do people come to think of themselves as gay, straight, pansexual, asexual, or another sexual identity? At what age do people start to develop a sense of themselves as sexual beings, and how do they make sense of these experiences? According to phase models, most people proceed sequentially through a similar series of phases as they discover and internalize a sexual identity. In these sections, we will summarize these phase models as well as other models that focus more on milestones or narrative themes.

Phase Models of Sexual Identity Development

According to phase models (summarized in Figure 9.1), sexual identity development consists of distinct emotional, psychological, social, and behavioral phases that mark important transitions in self-knowledge and self-definition. Note, however, that these phases do not occur in the same order for all people, nor does everyone experience all phases. That said, many sexual minority individuals experience an early phase of awareness during which they recognize a sense of differentness from others and first realize that people can differ in sexual orientation (Fassinger & Miller, 1997; Worthington, Navarro, Savoy, & Hampton, 2008). The awareness phase may be accompanied by feelings of confusion, fear, or bewilderment as sexual minority individuals seek to understand their private feelings and anticipate rejection or stigmatization by others. In contrast, some heterosexual people bypass the awareness phase of identity development if their socialization within a heteronormative culture never inspires feelings of difference. In such cases, heterosexual individuals may instead experience a phase of unexplored commitment characterized by a lack of conscious thought about whether to adopt a heterosexual identity and, for some, an unquestioning acceptance of the privileges of heterosexuality (Worthington, Savoy, Dillon, & Vernaglia, 2002).

Phase models of sexual identity development Models that posit distinct phases of emotional, psychological, social, and behavioral experiences that mark transitions in self-knowledge as people develop a sexual identity.


Figure 9.1 Phase Models of Sexual Identity Development

In the exploration phase, some sexual minority individuals explore same-sex attractions and erotic feelings, learn about other sexual minority people and communities, and continue to acquire more complex self-knowledge. For others, the exploration phase does not produce clear awareness and self-knowledge, perhaps due to internal or external resistance to same-sex sexuality. These individuals may then experience a phase of identity uncertainty during which their sexual orientation remains unclear. Heterosexual individuals in the exploration phase may actively explore and gain awareness of their attractions, sexual preferences, desired partner characteristics, and modes of sexual expression (Worthington et al., 2002). In this phase, some heterosexual people become aware of their heterosexual privilege and either question its fairness or accept it as right and just. As shown in Figure 9.1, however, some heterosexual individuals bypass the exploration phase altogether and remain in a prolonged phase of unexplored commitment.

During the deepening and commitment phase, information and experiences acquired through exploration lead to an increasing commitment to one’s sexual identity, greater self-knowledge, and active choices about how to relate to others sexually. For sexual minority individuals, this phase often involves further involvement in an LGBTQIA+ community. For heterosexual people, this stage may involve the refinement of conscious attitudes and moral values regarding heterosexual privilege and societal treatment of sexual minority individuals. During the final phase of integration and synthesis, sexual identity becomes fully integrated into an overall sense of self. Individuals who reach this phase experience their sexual identity as coherent, volitional, and integrated with other valued identities, such as race and ethnicity, religious orientation, gender, physical ability, and so on.

During the deepening and commitment phase of sexual identity development, individuals show a stronger sense of sexual identity and more active sexuality-related choices.

Source: ©

Asexual individuals often report experiencing a comparable but slightly more elaborate series of developmental phases (Robbins, Low, & Query, 2016). Like other sexual minority individuals, many asexual people recall an awareness phase during which they realized their difference from others. However, because asexuality is not well understood and people often lack language for describing it, asexual people may experience the awareness phase as identity uncertainty (see Figure 9.1). Initially, they may pathologize their own experiences and assume that something is wrong with them. Many asexual individuals then recall a distinct discovery of terminology phase during which they first encountered the language with which to describe their experiences. The Internet typically plays an important role in this phase, as asexual people search out online communities (such as the Asexual Visibility and Education Network, or AVEN; that validate their experiences and contribute to self-awareness. This phase then leads to the exploration phase, characterized by expanding knowledge, connections to other people and communities, and a tendency for some asexual individuals to embrace and internalize their asexual identity.

In the phase of identity acceptance and salience negotiation, asexual individuals may acknowledge and accept asexuality as a legitimate orientation and assess the centrality of asexuality to their sense of self. Some feel a strong sense of connection to this identity and derive meaning from it, while others view it as unimportant to their self-concept. Some asexual individuals may decide at this point to enter a coming-out phase in which they publicly label themselves and discuss their identity with others. Coming out may be especially important for those asexual individuals who desire to become involved in a romantic relationship. For instance, revealing their asexuality can help people to negotiate the terms of their relationships and discuss with partners whether or how much sexual activity is acceptable. Other asexual people, however, feel no need to reveal their identity to others and may therefore bypass the coming-out phase. These negotiations and decisions continue to the integration and synthesis phase, during which individuals integrate sexual identity into the self-concept as either a central or relatively peripheral aspect.

Some Muslim sexual minority individuals feel that their religious and cultural background erases and silences their sexual minority identity. Here, Muslim people participate in the Gay Pride Parade in London in 2019 to bring visibility to their intersecting identities.

Source: Guy Corbishley / Alamy Stock Photo

Most of the research on phase models of sexual identity development assesses relatively nondiverse samples of respondents. But how do ethnicity and religion shape sexual identity development? One qualitative study of Middle Eastern sexual minority individuals living in the United States illustrates how religious and cultural factors can complicate the development of sexual identity (Ikizler & Szymanski, 2014). These individuals noted that Middle Eastern cultures tend to deny and erase same-sex sexuality, making it very difficult for them to understand and interpret their own private experiences during the awareness phase. Furthermore, because Islam strictly prohibits same-sex sexuality, Muslim participants in the sample reported an incompatibility between their sexual minority and Muslim identities, leading to a prolonged phase of identity uncertainty. Several individuals described the Middle Eastern sexual minority community as invisible, small, and disjointed, which likely complicates their phases of exploration and of deepening and commitment. Others, however, described their dual identities as sexual and ethnic minority individuals as a source of resilience and strength. For instance, developing a stronger Middle Eastern ethnic identity in the United States helped one gay man cope with adversity as he gained awareness of his sexual minority identity. Finally, several people mentioned pride about bridging two seemingly unconnected worlds, excitement about their unique perspective on life, and a sense of responsibility to advocate for others.

Milestone models of sexual identity development Models that identify the timing, sequence, and tone of different milestones that many sexual minority individuals experience.

Milestone and Narrative Models of Sexual Minority Identity Development

Rather than identifying phases of identity development, milestone models of sexual identity development instead identify the timing, sequence, and tone of different milestones that many sexual minority individuals experience. Such milestones may include awareness of first same-sex attraction, labeling the self as a sexual minority individual, first same-sex sexual contact, and first disclosure of identity to others (Savin-Williams & Diamond, 2000). By tracking the ages and orders in which these milestones occur, researchers observe some interesting sex differences. Sexual minority girls generally become aware of same-sex attractions, experience their first same-sex sexual contact, and label their sexual identity at a slightly older age than boys. Relative to boys, girls more frequently experience their first same-sex attraction in emotional terms (e.g., falling in love) and have their first same-sex sexual experience in the context of a dating relationship. In contrast, relative to girls, boys more frequently experience their first same-sex attraction as primarily sexual and have their first same-sex sexual contact with a friend or stranger. These sex differences may reflect gender socialization patterns that encourage girls to prioritize the emotional components of sex and to confine sexual activity to relationship contexts, while boys experience greater freedom to prioritize the pleasurable, physical aspects of sex and to pursue sex without love.

Finally, the narrative approach to sexual identity development broadly considers how multiple sources of identity (e.g., race, culture, nationality) and pride interact to shape sexual identity development within specific contexts. One qualitative study using this approach groups relevant life experiences into classes of socializing structures (SSs) and individual decisions and actions (IDAs). SSs include social contexts and institutions that either empower or disempower sexual identity development, including family, friends, workplaces, community, religion, and culture. Within such contexts, sexual minority individuals often report experiencing contradictory forces, such as invisibility and support or hostility and celebration. IDAs include private experiences, such as discovering one’s sexuality, labeling the self and disclosing to others, acquiring and sharing knowledge, becoming an activist, and finding inspiration through creative works. These classes of experiences jointly influence each other in a nonlinear and flexible manner, with both of them shaped strongly by national and racial background (D. N. Shapiro, Rios, & Stewart, 2010).

Narrative approach to sexual identity development An approach that broadly considers how multiple sources of identity (e.g., race, culture, nationality) and pride interact to shape sexual identity development within specific contexts.


While phase models identify common phases that presumably unfold sequentially for most people, milestone models identify the timing of important turning points and narrative models focus on broad themes of similarity and difference within specific contexts. Which of these approaches do you think does the best job of describing sexual orientation development? If you identify with a sexual orientation, how did you experience the development of this part of yourself? Do you view your own development more in terms of phases, milestones, or contextual themes? If you were going to study sexual identity development, which approach would you adopt? Why?


Why do people differ in sexual orientation? Are people born with an unchangeable sexual orientation, or do life experiences shape our sexuality? The truth is we do not yet have a definitive answer to these questions, but there is no shortage of theories. Most contemporary approaches consider the roles of biological factors, social factors, or both types of factors in shaping sexual orientation. In the following sections, we cover several influential theories of sexual orientation. (These are summarized for you in Table 9.3.)

Table 9.3

Theories of sexual orientation range from primarily biological to integrative (combining biological and sociocultural factors).

Biological Theories

Early sexologists Richard von Krafft-Ebing (1886/1998) and Havelock Ellis (1915) theorized a biological basis of sexual orientation, but it would be decades before scientific methods advanced to the point where researchers could test these ideas in a rigorous manner. Now, we have substantial evidence that biology shapes sexual orientation. In terms of genes, the evidence indicates that sexual orientation is moderately heritable—and somewhat more so among men than among women. Heritability estimates for sexual orientation suggest that genes account for 14%—67% of the population variance in men’s sexual orientation and 8%—30% of the population variance in women’s sexual orientation (J. M. Bailey, Dunne, & Martin, 2000; Burri, Spector, & Rahman, 2015). More recently, results of a large-scale study of over 477,000 White adults indicate that about 32% of the variance in the tendency toward same-sex sexual activity is due to genes, but in very complex ways (Ganna et al., 2019). Rather than one or two genes coding for same-sex sexuality, it appears that many different genes, spread across the whole genome, each play a small role. Genetic approaches offer compelling evidence that variations in sexual orientation are encoded in human DNA, but they also leave many questions unanswered. For instance, if genes explain about one-third of the variance in human sexual orientation and same-sex activity, what explains the remaining two-thirds of the variance? Genetic approaches are not equipped to answer this question.

Sexologist A scientist who formally studies human sexuality.


For the first half of the 20th century, Sigmund Freud’s psychoanalytic theory was the “go-to” theory for explaining sexual orientation. The theory stated that family dynamics that occurred during a critical phase early in life (between the ages of 3 and 5) shaped a person’s sexual orientation. In most cases, family experiences during this phase lead children to develop as heterosexual through a process of identification with the same-sex (presumably heterosexual) parent. In some cases, however, a boy might develop a same-sex orientation if he has a domineering mother and an absent or passive father; a girl might develop a same-sex orientation if her father disappoints her deeply (Freud, 1920). However, research failed to offer any evidence that early family dynamics shape sexual orientation (Hooker, 1969; Whitam & Zent, 1984). While Freud’s ideas about the causes of sexual orientation are creative and provocative, those who seek evidence-based explanations must look elsewhere.

What about the role of hormones in sexual orientation? According to the neurohormonal approach, fetal exposure to sex hormones, particularly testosterone and estradiol, plays an important role in the development of sexual orientation (L. Ellis & Ames, 1987). As you may recall from Chapter 3 (“The Nature and Nurture of Sex and Gender”), the fetal brain and nervous system undergo a process of sexual differentiation between the second and fifth months of gestation, and this relies heavily on production of and exposure to sex hormones. Genes that code for biological sex guide the levels of these hormones, but other factors can also influence whether a fetus gets exposed to female-typical or male-typical levels of hormones. The neurohormonal approach proposes that fetuses (of any sex) exposed to female-typical hormone levels will display a preference for male sexual partners at puberty and that those exposed to male-typical levels will display a preference for female partners at puberty. In most cases, this process results in heterosexual orientations but, in some cases, it results in same-sex orientations.

Another biological approach examines whether fetal exposure to maternal antibodies (proteins used by the immune system to fight pathogens) plays a role in male sexual orientation. According to this explanation, the male fetal brain contains Y-linked proteins that elicit a maternal immune response. That is, pregnant women’s bodies treat certain Y-linked proteins as foreign invaders and release antibodies that bind to these proteins, which alters their role in male fetal development (Bogaert et al., 2018). Moreover, this maternal immune response grows stronger with each male fetus that a mother carries. After carrying a certain number of male fetuses, the mother’s body presumably produces enough antibodies to prevent the fetal brain from developing in a male-typical fashion, which increases the likelihood of male same-sex sexuality.

If this explanation were true, we should see that men’s likelihood of identifying as gay increases with the number of older brothers they have. And in fact, it does. The fraternal birth order effect refers to the well-established positive correlation between the number of older brothers a man has and his own likelihood of identifying as gay (Blanchard, 2004). A man’s odds of identifying as gay in adulthood increase by about 33% with every additional older, biological brother that he has. Interestingly, this effect is exclusive to men: Older sisters are not associated with the sexual orientation of later-born sons, and lesbian identification does not correlate with the number of older siblings of any sex. Moreover, this effect is observed in both Western and non-Western samples. For instance, the fa’afafine of Samoa—biological males who are raised in the female gender role and primarily have sex with men—have disproportionately more older brothers than do heterosexual, non-fa’afafine Samoan men (VanderLaan & Vasey, 2011). Finally, recent research finds that the blood plasma of mothers of gay sons contains elevated levels of certain antibodies (Bogaert et al., 2018), which is consistent with the notion that mothers’ antibodies can shape sons’ sexual orientation. But why would this happen? Some speculate that this maternal immune response evolved because it reduces the likelihood that later-born sons will compete against their brothers for access to mates when the mating pool is limited (E. M. Miller, 2000). While provocative and interesting, this hypothesis is speculative. Furthermore, exposure to maternal antibodies can only explain same-sex sexuality for about 15%—29% of gay men (Blanchard, 2004). After all, plenty of gay men do not have older brothers, and plenty of men with older brothers are not gay.

Fraternal birth order effect The positive correlation between the number of older brothers a man has and his likelihood of identifying as gay.

Evolutionary Theories

As discussed in previous chapters, evolutionary theories seek to identify how tendencies observed today might reflect genetically heritable adaptations to ancestral environments. While evolutionary and biological theories both focus on the role of genes in transmitting human traits, evolutionary approaches tend to focus more on big-picture explanations for why people inherit certain tendencies in the first place. Because people with a same-sex orientation reproduce at lower rates than heterosexual people (Iemmola & Ciani, 2009), some question how the genes that code for same-sex sexuality get transmitted. And yet, both female—female and male—male sexual behavior is evident in over 450 animal species around the world (Bagemihl, 1999), including 33 different primate species. So, how do same-sex orientations get passed on?

Alliance formation hypothesis The hypothesis that same-sex sexual activity is adaptive because it promotes emotional bonds and facilitates survival and resource sharing between pairs of friends.

Kin selection Helping behavior that is costly to the helper in the short term but beneficial in the long term because it increases the survival likelihood of the helper’s genetic relatives.

One evolutionary explanation, termed the alliance formation hypothesis, argues that same-sex sexual activity promotes beneficial friendship bonds between unrelated primate pairs. For instance, friends who bond through same-sex sexual activity are more likely to display reciprocal altruism, meaning that they more frequently risk their own safety or expend their own resources to assist and defend one another (Vasey, 1993). If such behavior increases survival rates, then it should get transmitted genetically from one generation to the next (provided that these individuals also engage in heterosexual mating). Although this hypothesis derives from studies of nonhumans, Kirkpatrick (2000) proposes that the same logic applies to human same-sex sexual activity as well. This hypothesis remains speculative, however.

Another evolutionary hypothesis explains male same-sex sexuality as a form of kin selection. In this view, male same-sex sexuality persists in the gene pool because the benefits that same-sex-oriented individuals bestow on their genetic relatives offset the costs to them of not reproducing. Specifically, if a gay man provides larger-than-average amounts of child-rearing assistance to his siblings, thereby increasing the likelihood that his nieces and nephews will survive and pass on their genes, then the genes that code for same-sex sexuality will get transmitted. This hypothesis lacks support in Western cultures, including the United States, United Kingdom, and Canada (Bobrow & Bailey, 2001; Rahman & Hull, 2005). However, Vasey and his colleagues find support for it among the fa’afafine. Specifically, fa’afafine show higher levels of altruism toward nieces and nephews than do heterosexual men and women (Vasey & VanderLaan, 2009), and they are culturally valued for their family loyalty. Thus, evidence for this theory is inconsistent, emerging in some cultures but not others.

Two fa’afafine friends.

Source: Education Images / Universal Media Group / Getty Images

Genes for male same-sex sexuality may also pass down if the relatives of sexual minority men are especially fecund, or likely to reproduce. Consistent with this fecundity hypothesis, the biological mothers and aunts of gay men tend to have more children than the biological mothers and aunts of heterosexual men (Iemmola & Ciani, 2009). Since men share many genes with their mothers and aunts, these women’s heightened fecundity may keep the genes that code for same-sex sexuality in the population.


Note that most (though not all) of the theories summarized in this section focus on explaining same-sex sexual orientation rather than heterosexuality. Why do you think this is? What (if anything) does this reveal about the perspectives and assumptions of the researchers? Does heterosexuality require explanation as well? Why or why not?

Fecundity hypothesis The hypothesis that genes for same-sex sexuality get passed on genetically because the female relatives of gay men produce more than the typical number of offspring.

Tipping point theory The theory that genes for same-sex sexuality get passed on because the same-sex relatives of gay and lesbian people have personalities that increase their likelihood of engaging in reproductive sex.

Biobehavioral model A model proposing that prolonged sex segregation combined with proximity, intimacy, and touch can lead people to develop novel sexual desires.

The tipping point theory uses a similar logic. This theory posits a group of genes that together code for same-sex sexuality in men and also for communal personality tendencies, such as kindness and sensitivity. Some men inherit the genes for communal personality but remain heterosexual. Because communal traits are desirable to women, these men have a reproductive advantage over their peers. Their desirable personalities increase their mating opportunities, and they pass on their genes with relative success. Men who inherit many of these genes, however, reach a tipping point at which their own mate preferences become reversed, and they demonstrate a same-sex orientation (E. M. Miller, 2000). In partial support of this theory, heterosexual men who possess more communal traits do tend to have more female sexual partners (Zietsch et al., 2008), suggesting that they are highly attractive to women.

Tipping point logic may also explain female same-sex sexuality. Andrea Burri and her colleagues found that reports of having more agentic personality traits in childhood predicted both same-sex attraction and larger numbers of sexual partners in adult women (Burri et al., 2015). Moreover, Burri proposes that common genetic factors influence all three of these factors (personality, adult same-sex attraction, and number of sexual partners). Thus, genes that code for lesbian sexual orientation may also code for agentic personalities and a tendency to pursue more sexual partners. Importantly, the links between agentic personality and more sexual partners emerge among both lesbian and heterosexual women. If heterosexual women who share genes with lesbians (such as their sisters) have more reproductive sex with men, then the genes that code for same-sex sexuality in women will remain in the gene pool.

The Integrative Approach

Integrative approaches—reflecting a theme you have seen throughout this book—consider how biological and social—environmental factors jointly contribute to the development and experience of sexual orientation. For example, Lisa Diamond’s (2003) biobehavioral model proposes that sexual desire toward same-sex individuals can develop in certain social environments, facilitated by oxytocin. For instance, in sex-segregated environments such as boarding schools, sororities and fraternities, athletic teams, and the military, people may form intense passionate friendships with same-sex peers that are indistinguishable from romantic love. Historians and anthropologists have noted these passionate friendships between heterosexual youth in ancient Greece, Africa, Melanesia, Samoa, Guatemala, Native American cultures, and contemporary Western cultures. In the context of passionate friendships, friends tend to share prolonged physical proximity, social intimacy, and touch, which can increase oxytocin levels. Oxytocin, in turn, can foster sexual arousal and attraction. Thus, same-sex love can turn into same-sex desire due to a complex interaction between environmental and biological factors. The biobehavioral model is particularly useful for explaining how people can unexpectedly develop feelings of sexual attraction toward persons of a sex that does not typically attract them, as in the case of a woman who identifies as heterosexual but develops feelings of sexual desire for another woman.

Evaluation of Theories

So which theory does the best job of explaining sexual orientation? Unfortunately, there is no simple answer to this question. Both biological and environmental factors shape the development of sexual orientation, but researchers do not fully understand the precise ways in which these factors interact. And while some of the theories summarized here have empirical support, none of them explains all of the variance in sexual orientation.

Finally, you may have noticed a couple of biases in the theories we covered here. First, note that many theories of sexual orientation primarily focus on explaining same-sex sexuality rather than heterosexuality or even sexuality more broadly. This likely reflects the heterocentric assumption that heterosexuality is universal and “normal,” while other sexualities are deviations from this norm that require explanation (think back to the material on heterocentrism as a cultural ideology from Chapter 6). Second, note also that many theories focus more on explaining male than female sexual orientation. Why might this be? Does this pattern reflect an androcentric tendency to prioritize men’s experiences over women’s? Or alternatively, might male sexual orientation be easier to explain than female sexual orientation?


People commonly believe that women—compared with men—have less interest in casual sex, are more selective in choosing sexual partners, and are less sexually assertive. Recall from our discussions of parental investment theory (see Chapter 3, “The Nature and Nurture of Sex and Gender,” and Chapter 5, “The Contents and Origins of Gender Stereotypes”) that evolutionary theories locate the origins of these sex differences in evolved tendencies. Because women invest more than men do in gestating and caring for offspring, they should have evolved a tendency to be highly selective about choosing mating partners, uninterested in casual sexual encounters that might leave them pregnant, and relatively sexually reserved.

But are women really less interested than men in casual sex? Terri Conley and her collaborators think not. In fact, Conley considers many popular beliefs about gender and sexuality to be myths that do not hold up to scrutiny (Conley, Moors, Matsick, Ziegler, & Valentine, 2011). Think about the stereotype that men are relatively unselective when it comes to choosing sexual partners. According to this view, the average heterosexual man who walks into a room full of potential dates will find more of them desirable as sexual partners than will the average heterosexual woman. But Finkel and Eastwick (2009) questioned whether this reflects an evolved, biological sex difference or whether it can be explained by gender norms. Specifically, they asked whether the simple act of approaching a potential partner, as opposed to being approached, might explain men’s attraction to a wider range of partners. To examine this, the researchers randomly assigned women and men at heterosexual “speed-dating” events to play the roles of either rotators (daters who walked from date to date) or sitters (daters who remained seated and got approached by multiple dates). Each person had 4-minute dates with approximately 12 different other-sex partners, after which they rated their sexual attraction to each partner. When men rotated and women did not, men reported more sexual attraction to their partners than women did. However, as shown in Figure 9.2, when women rotated and men did not, the sex difference in sexual attraction disappeared—women and men reported equal attraction to their partners. Thus, given the social norm that men rather than women should approach potential dates, men may exhibit greater sexual interest than women because of their role as “the suitor” in dating contexts and not because of an evolved tendency.


Figure 9.2 Sex Differences in Romantic Desire

Source: Finkel and Eastwick (2009).

What about the notion that men are more sexually assertive than women? Sexual assertiveness refers to people’s perceived control over their sexual intimacy, with more sexually assertive people being more likely to initiate sexual encounters and communicate their needs and desires within such encounters. Widespread gender stereotypes portray men as much more sexually assertive than women, but when Lammers and Stoker (2019) measured power and sexual assertiveness in nearly 2,000 women and men from the Netherlands, British Isles, United States, and Southeast Asia, an interesting finding emerged. Regardless of their sex, people who held more powerful workplace positions also reported more sexual assertiveness in the context of their personal relationships. That is, occupying a more powerful work role was associated with greater assertiveness regarding sexual intimacy, and this was true for women and men across cultures. Thus, observed sex differences in sexual assertiveness may result less from evolved tendencies than from socially constructed differences in power between men and women.

In a similar vein, Conley and her collaborators described and systematically debunked several sex differences in sexuality that people commonly accept as fact by pointing out conditions under which each one fails to emerge (Conley et al., 2011). These are summarized in Table 9.4. What do you think about these beliefs and their alternative interpretations? In the sections that follow, we will consider several aspects of sexuality for which sex differences do—and do not—emerge.

Sexual Behavior, Attitudes, and Brain Activity

Petersen and Hyde (2010) conducted a meta-analysis of sex differences in sexuality from 1993 through 2007 to determine whether men truly are the more sexual sex. While most of the studies included were conducted in North America and Europe, approximately 30% were conducted in Latin America, Africa, the Middle East, and East Asia. They reviewed research on 14 different sexual behaviors (e.g., vaginal, anal, and oral sex; masturbation; pornography use; and cybersex), and 16 sexual attitudes (e.g., attitudes about casual sex, extramarital sex, and same-sex sexuality). Overall, men reported more sexual experience than women did on 13 of the 14 behaviors, but most of the effects were in the small (d values between 0.11 and 0.35) and close-to-zero (d < 0.11) ranges. Men also reported more permissive attitudes about sex than women on 9 of 16 measures, but again, most effects were small and close-to-zero. Medium effects emerged only for men reporting greater frequency of casual sex, masturbation, and pornography use and more favorable attitudes toward casual sex. In contrast, women reported greater frequency of same-sex sexual experiences (with a close-to-zero effect size, d = −0.05) and more favorable attitudes about sex accompanied by emotional commitment. They also reported stronger support for sexual minority rights and same-sex marriage, although these effects were small. Finally, sex differences in reported rates of adolescent sexual intercourse have decreased somewhat over time, due primarily to decreases in adolescent boys’ reports of intercourse. Summarizing across all of these patterns, Petersen and Hyde concluded that the sexes are more similar than different in their sexual behavior and attitudes and that this similarity increases with time. This may remind you of the finding described earlier that young women and men in Thailand show smaller sex differences in sexual behavior than the older generations do (Techasrivichien et al., 2016).

Table 9.4

Terri Conley and her collaborators summarized several sex differences in relationship preferences and sexuality that have been commonly accepted as fact (Conley et al., 2011). They then systematically debunked each “fact” by pointing out conditions under which it fails to emerge. What do you think about these beliefs and alternative interpretations?

Source: Adapted from Conley, Moors, Matsick, Ziegler, and Valentine (2011).

Note that all of the behaviors and attitudes summarized in Petersen and Hyde’s (2010) meta-analysis were based on self-reports. But as you will read in the chapter debate (“Do Men Have a Stronger Sex Drive Than Women?”), gender role expectations may encourage men to exaggerate their reported interest in sex and the frequency of their past sexual experiences, while encouraging women to downplay these same things. Therefore, some researchers bypass self-reports altogether and instead examine sex differences in brain activity during exposure to erotic images and videos. When researchers expose women and men to erotic images in the lab, men routinely report feeling more sexually aroused than women do (Rupp & Wallen, 2008). And yet, a meta-analysis of brain imaging studies indicates no sex differences in neuronal responses to erotic stimuli. Specifically, visual sexual stimuli elicit an “arousal network” in the brain—that is, a pattern of activation of brain regions throughout the cerebral cortex and subcortical structures—that does not differ significantly between women and men (Mitricheva, Kimura, Logothetis, & Noori, 2019). Based on this, some conclude that women and men have similar cognitive and perceptual responses to sexual stimuli, and that any observed sex differences in self-reported arousal must therefore reflect other factors such as learning and socialization.


Who do you think has a stronger sex drive, men or women? Stereotypes usually portray men as the more lustful sex, but researchers disagree on whether men actually have a stronger sex drive or whether women and men have similar sex drives. Here we define sex drive as the motivation or desire to engage in sexual activity (Baumeister, Catanese, & Vohs, 2001). Let’s consider the arguments for both positions.


Evidence for a stronger male sex drive comes from a variety of sources. Men self-report having a stronger sex drive than women do, and this pattern emerges across cultures (Lippa, 2009; Schmitt, 2005). Men also report thinking about sex more often than women do (Fischtein, Herold, & Desmarais, 2007). In one study, college men and women reported all of their sexual thoughts and fantasies over 7 days (J. C. Jones & Barlow, 1990). Men reported an average of eight thoughts per day, while women reported about five thoughts per day.

On average, men report wanting to have sex more often than women do. Heterosexual men report desiring sex more frequently than heterosexual women do, in both dating and marriage relationships (Willoughby, Farero, & Busby, 2014; Willoughby & Vitas, 2012). Same-sex couples show the same pattern, with gay male couples reporting more frequent sex than lesbian couples (Blair & Pukall, 2014). Men also tend to seek greater sexual variety. When questioned about their ideal number of sexual partners, men report wanting more partners than women, on average (Pedersen, Miller, Putcha-Bhagavatula, & Yang, 2002). Men also tend to have more positive attitudes toward casual sex compared with women, and they report masturbating more frequently than women (Petersen & Hyde, 2010). Across the world, men are much more likely than women to pay for commercial sexual services, prostitutes, and other erotic entertainment (Hakim, 2015). Taken as a whole, these studies provide compelling evidence that men have a stronger sex drive than women.


While true that, on average, men report wanting more sexual partners than women do, this is misleading. Gender norms may lead men to exaggerate their sexual desires and behaviors and conversely lead women to underreport theirs. In fact, one study showed that when participants thought they were connected to a “lie detector” that could determine the truthfulness of their answers, women and men reported similar rates of sexual behavior (M. G. Alexander & Fisher, 2003). Furthermore, the distributions of desired sexual partners are highly skewed, meaning that a small number of men report extremely high numbers, and this inflates the statistical mean for men. When we look at the median values instead—the values that fall at the 50th percentile of each distribution—we see that women and men both claim to desire just one partner over the next 30 years (Pedersen et al., 2002). Thus, most men and women have similar desires.

The findings that men want more sexual activity and more casual sex than women may also be misleading. For example, while gay male couples do report having sex more frequently than lesbian couples, lesbian couples report having sexual encounters that last longer than those of gay male and heterosexual couples (Blair & Pukall, 2014). Thus, if one considers not just frequency but duration of sex, men’s tendency toward more sexual activity goes away. Furthermore, women express as much willingness to accept casual sex offers as men if they believe that the potential sex partner is “a great lover” (Conley, 2011). In short, findings regarding men’s greater sex drive than women’s may reflect skewed data or other factors such as duration of sexual encounters and expected pleasure.

What do you think? Which evidence do you find most and least convincing? Why?

Orgasm Frequency and Sexual Satisfaction

Having an orgasm during sexual activity is a strong predictor of overall sexual satisfaction (Haning et al., 2007), and orgasm frequency predicts not only sexual satisfaction but also relationship satisfaction for heterosexual, lesbian, and bisexual women, as well as for heterosexual men (Frederick, St. John, Garcia, & Lloyd, 2018). Orgasm rates do not appear to differ between Latinx, Black, Asian, Native American, or White young adults (A. M. Galinsky & Sonenstein, 2011), but they differ consistently by sex: Women orgasm less frequently than men in the context of heterosexual sexual activity, a phenomenon referred to as the orgasm gap. For example, in an investigation of over 2,600 college students reporting on their most recent hookup (defined as a casual sexual encounter with someone who is not one’s relationship partner), 70% of men and 34% of women had an orgasm during vaginal intercourse (England, Shafer, & Fogarty, 2008). As shown in Figure 9.3, the size of the orgasm gap during hookups differs by type of sexual activity, but in each case, men orgasm at higher rates than women do.

Orgasm gap The tendency for women to have lower rates of orgasm than men during heterosexual sexual encounters.

Both biological and social factors affect orgasm frequency. Some research indicates that genes explain about 31% of the population variance in women’s rates of orgasm during sexual intercourse (Dawood, Kirk, Bailey, Andrews, & Martin, 2005). This may occur because genes affect the distance between the clitoris and the vaginal opening (Wallen & Lloyd, 2011). For women with a larger distance, the clitoris receives less stimulation during heterosexual intercourse, and clitoral stimulation directly relates to orgasm for women.


Figure 9.3 The Orgasm Gap

Source: England, Shafer, and Fogarty (2008).

In terms of social factors, the sex of women’s sexual partners also plays a role in orgasm rates. Reports that they “usually or always” orgasm during sexual intimacy are made by 65% of heterosexual women, compared with 86% of lesbian women, 95% of heterosexual men, and 89% of gay men (Frederick et al., 2018). In other words, women orgasm relatively less frequently during sexual encounters with men than during sexual encounters with other women. However, the heterosexual orgasm gap is smaller in the context of established relationships than in hookups because men in relationships more frequently engage in foreplay activities that produce clitoral stimulation (Armstrong, England, & Fogarty, 2009). For instance, receiving oral sex predicts orgasm among heterosexual, lesbian, and bisexual women (Andrejek & Fetner, 2019; Frederick et al., 2018), but women receive oral sex less often than men do from hookup partners. Similarly, for heterosexual and bisexual (but not lesbian) women, the duration of sexual encounters correlates positively with orgasm frequency. Therefore, if sexual activity during the average hookup does not last very long, then the likelihood of women orgasming decreases. Finally, in the context of casual sexual relationships, women may be reluctant to initiate or request the sort of clitoral stimulation that will lead to orgasm. Heterosexual women in one qualitative interview study reported not requesting clitoral stimulation during sexual activity out of fear of damaging their partner’s ego (Salisbury & Fisher, 2014).

All of these factors combined—lower likelihood of foreplay, brief duration of sexual activity, and reluctance to request clitoral stimulation—may add up to women being much less likely than men to orgasm during hookups. And this, in turn, may contribute to sex differences in attitudes toward casual sex. In fact, results of a recent study found that women tend to react less positively than men to casual sexual encounters primarily because they are less likely to orgasm during such encounters (Piemonte, Conley, & Gusakova, 2019).

The heterosexual orgasm gap is smaller in established relationships than in hookups because couples in relationships more often engage in sexual behaviors that stimulate female orgasm.

Source: ©

One interesting question concerns the effects (if any) of genital reconstructive surgery (GRS) and hormone treatments on the orgasm rates and sexual desires of transgender individuals. Small sample sizes and large variance in the findings across relevant studies make drawing conclusions about this question difficult. Moreover, many studies lack comparable data from both before and after individuals undergo treatments. However, one review of the literature concluded that transwomen generally report high orgasm rates following GRS (C. Klein & Gorzalka, 2009). In a study of 232 transwomen, 85% reported achieving orgasm from either masturbation or sexual intercourse after surgery. However, the findings regarding spontaneous sexual desire, such as fantasies or thoughts about sex, vary a lot for transwomen: Some report an increase following surgery, some report a decrease, and some report no change. In contrast, transmen tend to report an increase in sexual desire more consistently, likely resulting from testosterone treatments, as well as high rates of orgasm after surgery: Between 78% and 100% of transmen report reaching orgasm during either masturbation or intercourse after GRS.

Rather than focusing on orgasm rates, some research examines how hormone therapies can transform people’s sexual desires and experiences. One qualitative study of transwomen revealed that hormone treatments increased the erogenous sensitivity of their body parts including their nipples, back and neck, inner thighs, face, and ears. As a result, several of the women reported having more sensual pleasure during sex, with more prolonged “full-body” orgasms than they experienced prior to their transition (Rosenberg, Tilley, & Morgan, 2019).


Given the biological and social factors that contribute to the orgasm gap, what steps might people take to close this gap? Who bears the greatest responsibility in increasing women’s orgasm rates: women, their partners, or society? Do you view the orgasm gap as unfair? Why or why not?

Sexual Fluidity

As discussed earlier in this chapter, people sometimes change how they experience their sexuality or develop novel romantic or sexual feelings toward individuals of a sex that does not usually attract them. In one longitudinal study, Lisa Diamond (2008) found that 67% of sexual minority women exhibited sexual fluidity by changing how they identified their sexual orientation over a 10-year period. Another large study of transgender and gender-nonconforming adolescents found that 58% reported changes in their sexual attractions over their lives (Katz-Wise, Reisner, Hughto, & Keo-Meier, 2016). In contrast to these studies that used convenience samples, a large, nationally representative sample of emerging adults found much lower rates of sexual orientation change over time: While 7.4% of young adults changed to a more same-sex-oriented identity over time, 4.4% changed to a less same-sex-oriented identity and 88.2% reported no change (Everett, 2015).

Sexual fluidity The tendency for people’s sexual orientation or sexual identity to change across time.

Women generally demonstrate more sexual fluidity than men. Roy Baumeister (2000) reviewed evidence collected from thousands of respondents over several decades. He found that women’s sexual orientation tends to change more over their lives compared with men, and women more frequently exhibit sexual behaviors that differ from their private attitudes and feelings. For example, lesbian women consistently report more heterosexual sexual experiences than gay men, and heterosexual women report more same-sex sexual desires and experiences than heterosexual men. In general, women exhibit discrepancies between the identity, motivation, and behavior components of their sexual orientation more often than men do (Norris, Marcus, & Green, 2015). In fact, relative to men, women show greater sexual response to both male and female sexual stimuli regardless of their sexual orientation. For instance, heterosexual and lesbian women become genitally aroused in response to both female and male sexual stimuli, while heterosexual and gay men become genitally aroused only in response to the type of sexual stimuli that corresponds with their sexual orientation (Chivers, Rieger, Latty, & Bailey, 2004). Similarly, among heterosexual women, stronger sex drive predicts increased sexual attraction to both women and men, whereas among heterosexual men, stronger sex drive predicts sexual attraction to women only (Lippa, 2006). Women, compared with men, also more strongly endorse the general idea that sexual orientation is a fluid rather than a fixed thing (Lloyd & Galupo, 2019).

Why might this be the case? To explain women’s greater sexual fluidity, Lisa Diamond (2007) proposes that men’s overall pattern of sexual desire is driven primarily by sexual proceptivity, which is a hormonally driven, internal motivation to initiate sexual activity. In contrast, women’s overall pattern of sexual desire is driven primarily by sexual arousability, which is the flexible capacity to become aroused in response to sexual stimuli. If women are generally more arousable than men, then women’s sexual desires will more frequently be shaped by external sexual stimuli and contexts as well as by learning and conditioning. As a result, women should generally show more malleability in their day-to-day sexual desires, including shifts over time in their desires for same- and other-sex partners.


Sexual Trajectories

Are there sex differences in the age at which people reach their sexual peak, or the height of their interest in and enjoyment of sexual activity? People commonly assume that men reach their peak approximately 10 years younger than women. Both college students and middle-aged adults estimated that men peak sexually between the ages of 19 and 24, while women peak sexually between the ages of 28 and 34 (Barr, Bryan, & Kenrick, 2002). This belief has roots in the classic work of Albert Kinsey, who wrote that men desire sexual contact most strongly in their early years, while women’s sexual interest grows with age (Kinsey, Pomeroy, Martin, & Gebhard, 1953). But how valid is this assumption? The answer is complicated and depends on how researchers define sexual peak. On a biological level, there is little evidence that the hormone levels of women and men follow different trajectories or that men’s hormones peak at a younger age (Baldwin & Baldwin, 1997). In terms of sexual behavior, women and men both show similar, gradual increases in sexual activity from puberty through midlife, a plateau between the ages of 45 and 55, and then gradual declines over the next several decades (Mercer et al., 2013). This again contradicts the notion that the sexes reach their peaks at different ages.

Sexual peak The height of a person’s interest in, enjoyment of, or engagement in sexual activity over time.

What about in terms of sexual desire? Research conducted in the United States and Canada suggests that men peak slightly earlier than women do. Men report their highest levels of lust in their late 20s, whereas women report their highest levels of lust a few years after that, in their early to mid-30s (Schmitt, Shackleford, Duntley, & Tooke, 2002). Moreover, women between the ages of 27 and 45 report stronger motivation to engage in sexual intercourse, more frequent and intense sexual fantasies, and greater willingness to have casual sex compared to women ages 18—26 and 46 or older (Easton, Confer, Goetz, & Buss, 2010). These findings point to a small sex difference in sexual desire trajectories, although some scholars caution against putting too much stock in these self-report data given that they come exclusively from Western cultures.

Regardless of when people reach their sexual peak, sexual activity tends to be highest between the ages of 16 and 44, followed by a plateau and then a gradual decline over the next several decades (Mercer et al., 2013). For instance, one longitudinal study of Singaporean couples found that rates of sexual activity declined from five to six times per month before age 55 to three times per month after the age of 55 (Goh, Tain, Tong, Mok, & Ng, 2004). Men also become less likely to orgasm during sex as they get older, regardless of sexual orientation (Frederick et al., 2018).

Corresponding to this trajectory of sexual activity over the life course, the importance of sexual health to people’s overall quality of life follows a similar pattern: As people age from their 20s to early 40s, sexual health plays an increasingly important role in general quality of life. However, the importance of sexual health for quality of life declines for women and men between the ages of 50 and 80. That said, sexual satisfaction correlates with both physical and mental health across adults of different ages (K. E. Flynn et al., 2016). Studies that track adults through their 60s and 70s, across both Western and Eastern cultures, find that people who have regular sexual activity, more frequent orgasms, and more enjoyable sex also have lower mortality rates (L. M. Diamond & Huebner, 2012). Thus, while people may experience declines in sexual activity as they age, engaging in regular sexual activity still correlates with good health.

The Medicalization of Sexual Changes

Around the middle of life, adults begin to experience hormonal changes that can influence their sexual behavior and their experiences of sexuality. For women, menopause—the cessation of menstruation and fertility, accompanied by stable declines in estrogen levels—usually occurs between the ages of 45 and 55 (although this can vary a lot). Perimenopause, the phase prior to menopause, usually occurs in the early to mid-40s. In this phase, fertility begins to decline, estrogen levels rise and fall, and menstrual periods and ovulation may become irregular. Women’s sexual desire often declines with the onset of menopause, although many people continue to have satisfying sexual activity well beyond menopause. Also, around the age of 50, men tend to lose erectile function and often report having more difficulty either achieving or maintaining an erection, a condition commonly referred to as erectile dysfunction. Both of these phases—menopause and the loss of erectile function—are natural and normal (if sometimes frustrating and unpleasant) physiological processes. And yet, the term erectile dysfunction portrays men’s transition as a medical illness. Similarly, the pervasive treatment of menopause with drug therapies encourages a perception of menopause as unnatural and medically problematic.

Regular sexual activity and sexual satisfaction correlate positively with physical and mental health throughout adulthood and old age.

Source: ©

Menopause The cessation of menstruation and fertility, accompanied by stable declines in estrogen levels, that usually occurs between the ages of 45 and 55.

Erectile dysfunction A condition characterized by loss of erectile function and difficulty achieving or maintaining an erection.

Feminist scholars have long written about the medicalization of sexuality, or the process whereby societies view normal, natural conditions and transitions as medical illnesses that require diagnoses and treatments. Medicalization can be problematic because it increases people’s reliance on unnecessary and sometimes ill-advised treatments, makes people feel like there is something wrong with them, and casts healthy people into the role of medical patients. For instance, the medical view of menopausal women as “hormone deficient” encourages women to use hormone replacement therapies (HRTs), often consisting of estrogen and/or progesterone in pill or skin patch form. While members of the medical community recommend HRTs based on the claim that menopausal declines in estrogen put women at an increased risk of illnesses like heart disease, large-scale epidemiological studies show that some HRTs increase women’s risk of developing breast cancer. A review of studies of over 100,000 postmenopausal women worldwide found slightly elevated risks of breast cancer among women who had ever used HRTs compared to those who never used them (Collaborative Group on Hormonal Factors in Breast Cancer, 2019). Moreover, breast cancer risks were higher for HRTs containing both estrogen and progesterone than for estrogen-only HRTs, and risks were also higher for women who used HRTs for longer periods of time.

Medicalization The process whereby normal, natural physical conditions and transitions are viewed as medical illnesses that require diagnoses and treatments.

The medicalization of sexuality also focuses attention on biological factors that underlie sexuality and ignores social, emotional, and cultural factors. Consider Viagra, the wildly successful “impotence drug” that hit the market in 1998. Viagra presumably solves the “problem” of erectile dysfunction through physiological means, by increasing blood flow to the penis. And yet, erections are not only a physiological phenomenon—they also reflect psychological arousal, mood and emotion, context, stimulation, culture, partners, sexual techniques, and life stage (Tiefer, 2006). Not only does the medicalization of impotence reduce the complexity of erections to a single, physiological cause (i.e., blood flow), it also reduces men’s sexuality to the rigidity of their erections (Tiefer, 1994). This focus on penile rigidity as the essence of men’s sexuality ignores other ways in which men can and do experience sexual gratification, both with and without partners.

Declines in sexual interest and activity later in life are normal. While some people may wish to seek medical treatments to help ease them through midlife transitions, such treatments are often unnecessary, may bring health risks, and can subtly influence how people think about their own sexuality. With or without medical interventions, sexual activity can contribute to overall well-being and physical health well into the later decades of life. In fact, researchers now recognize the importance of positive sexual activity for a healthy and happy life (L. M. Diamond & Huebner, 2012). And self-acceptance appears to be a key component of healthy sexuality, regardless of what (if any) sexual identity label one adopts, whom one loves and desires, and what sexual behaviors one pursues.

Viagra is commonly prescribed for erectile dysfunction.

Source: ©


The search for impotence cures is nothing new. Over the centuries, men have tried to improve the vigor of their sexual functioning with various remedies. Some examples include chewing on garlic and leeks (ancient Rome), drinking the secretion of Spanish fly beetles (ancient Greece), roasting and eating wolf penises (medieval Europe), having goat testicles surgically implanted into the scrotum (United States, early 20th century), and using radium suppositories (United States, the 1920s). Alas, none of these remedies proved reliably effective, and some—such as radioactive suppositories—likely did serious damage to men’s health (Paulus, 2016).


· 9.1 Locate current understandings of sexuality and sexual orientation within social, cultural, and historical contexts.

Psychologists define sexual orientation as an enduring pattern of cognitive, motivational, and behavioral tendencies that guides how people experience and express their sexuality. Sexuality refers to the capacity for sexual experiences. The concept of sexual orientation is a relatively recent, Western development. In different cultures and times, same-sex sexuality has meanings that have little to do with sexual orientation. The tendency to define and label sexual orientation may have emerged as a means of controlling people’s erotic behavior.

· 9.2 Describe the multiple dimensions of sexual orientation, and analyze different models of sexual identity development.

Sexual identity refers to the label that people use to describe their sexual orientation and the emotional reactions that they have to this label. Most people identify as gay/lesbian, straight, or bisexual, but there are many other categories and labels whose prevalence differs across cultures. Evolutionary theories view love (attachment) and sexual desire (lust) as motivational states that compel people to seek proximity to and mate with others. Sexual desire presumably encourages reproductive mating, and love encourages pair bonding (attachment to a mate for the purpose of raising infants). The behavioral component of sexual orientation consists of the sexual acts that people perform both alone and with others. Importantly, not all people experience the cognitive, motivational, and behavioral components of sexual orientation in a unified, consistent manner.

Phase models of sexual identity development describe distinct phases that mark important transitions in self-knowledge as people develop a sexual identity. While gay, lesbian, and bisexual individuals usually go through phases of awareness, exploration, deepening and commitment, and integration and synthesis, they may also go through an identity uncertainty phase. Heterosexual individuals may bypass the awareness and exploration phases and experience a prolonged unexplored commitment phase. Asexual individuals may experience unique phases of terminology discovery, coming out, and identity acceptance and salience negotiation. Instead of phases, milestone models identify the timing, sequence, and tone of different sexual identity milestones, while narrative approaches broadly consider how multiple sources of identity and pride interact to shape sexual identity development within specific contexts.

· 9.3 Evaluate biological, evolutionary, and integrative theories of sexual orientation.

Biological theories propose that sexual orientation is moderately heritable, associated with fetal exposure to sex hormones, and predicted (among men) by having more older brothers. Evolutionary theories posit that carrying the genes for same-sex sexuality confers an advantage by increasing altruism and helping among friends and genetic relatives or by increasing the attractiveness and fecundity of one’s genetic relatives. Integrative approaches, such as the biobehavioral model, consider how biological and social environments shape sexual orientation and can explain how people sometimes develop novel sexual attractions that follow from romantic love. Sexual orientation is a complex phenomenon that likely reflects many underlying causes, and no single theory fully accounts for the differences in sexual orientation across all people.

· 9.4 Explain sex differences in sexuality, including attitudes and behaviors, orgasms and sexual satisfaction, and sexual fluidity.

People commonly assume that women are less sexual and hold less permissive sexual attitudes than men. However, meta-analyses show that most sex differences in sexual behavior and attitudes are in the small and close-to-zero ranges. As one exception, women have orgasms less often than men in the context of casual heterosexual sex and hookups (the orgasm gap). The orgasm gap is smaller, however, in committed heterosexual relationships and when male partners engage in more stimulation of the clitoris. Both transwomen and transmen report high rates of orgasm after genital reconstructive surgery, although transmen consistently report higher rates of orgasm and sexual desire than transwomen. Transwomen sometimes report different (longer, more full-body) orgasms after transitioning. Women tend to show more sexual fluidity than men, meaning that they more frequently experience changes in sexual orientation or sexual identity across time.

· 9.5 Understand issues in sexuality across the life course, such as sexual peaks and the medicalization of sexual changes.

For both women and men, sexual interest increases from puberty through midlife and then gradually declines from age 55 through the next several decades. While women and men do not appear to “peak” at very different ages, either in terms of hormones or behavior, men tend to report their highest levels of sexual desire in their late 20s, and women report their highest levels in their early 30s. Women also report stronger motivation to engage in sexual intercourse during the perimenopause phase, which is the phase preceding menopause. Menopause marks the end of menstruation and women’s fertility, a period when estrogen levels and women’s sexual interest typically decline. Men around this age may also lose erectile function and have fewer orgasms. The diagnosis of erectile dysfunction in men reflects the medicalization of sexuality, whereby society views normal changes in sexual functioning as medical illnesses that require treatments. Men may be encouraged to take Viagra, which tends to reduce men’s sexuality to the rigidity of their erections. Physicians often encourage menopausal women to take hormone replacement therapy, but this can increase the risk of breast cancer. Regardless of these physical changes and declines in rates of sexual behavior, women and men can maintain satisfying sexual lives through old age, and sexual activity relates positively to good physical health, well-being, and long life.

Test Your Knowledge: True or False?

· 9.1. Less than 5% of the U.S. population identifies as exclusively gay or lesbian. (True: Just under 5% of the population identifies as exclusively gay or lesbian.) [p. 315]

· 9.2. Many asexual people report difficulty in understanding their internal experiences of their sexuality because they lack the language to describe these experiences. (True: Because asexuality is not well understood, asexual people often lack the language to describe and understand their experiences until they first encounter the relevant terminology.) [p. 315]

· 9.3. Recent evidence suggests that most American children and teenagers have either sent or received sexts (sexual texts, images, or videos) via mobile phone. (False: Relatively small percentages of children send or receive sexts.) [p. 319]

· 9.4. Genital reconstructive surgery typically makes it difficult for transgender people to have orgasms. (False: Transgender people report relatively high rates of orgasm following surgery.) [p. 340]

· 9.5. While men experience their sexual peak between the ages of 19 and 25, women reach their sexual peak around the ages of 30—35. (False: There is little evidence that men and women “peak” sexually at such disparate ages.) [p. 342]

Descriptions of Images and Figures

Back to Figure

The model is as follows:

Under Lesbian, Gay, Bisexual, the following components are connected by linear arrows:

1. Awareness,

2. Exploration,

3. Identity uncertainty,

4. Deepening and Commitment,

5. Integration/Synthesis.

An arrow connects the two components Exploration and Deepening and Commitment.

Under Heterosexual, the following components are connected by linear arrows:

1. Unexplored Commitment,

2. Awareness,

3. Exploration,

4. Deepening and Commitment,

5. Integration/Synthesis.

An arrow connects the two components Unexplored Commitment and Deepening and Commitment.

Under Asexual, the following components are connected by linear arrows:

1. Awareness/Identity Uncertainty,

2. Discovery of Terminology,

3. Exploration,

4. Identity Acceptance and Salience Negotiation,

5. Coming Out,

6. Integration/Synthesis.

Back to Figure

The graph is described as follows:

The horizontal axis shows men and women rotated.

The vertical axis shows the scale of romantic desire from 1 to 7 in increments of 1.

When men were the rotators and women were the sitters, the approximate value of the romantic desire was:

1. Men: 5.2;

2. Women: 4.8.

When women were the rotators and men were the sitters, the approximate value of the romantic desire was:

1. Men: 5.0;

2. Women: 4.9.

Back to Figure

The graph is described as follows:

The horizontal axis shows different types of heterosexual hookup activities in men and women.

The vertical axis shows the percentage of orgasm from 0% to 90% in increments on 10.

The approximate rate of orgasm is:

1. Hand Stimulation:

1. Women: 15%

2. Men: 20%

2. Oral Sex:

1. Women: 25%

2. Men: 55%

3. Intercourse:

1. Women: 35%

2. Men: 70%

4. Intercourse and Oral Sex:

1. Women: 50%

2. Men: 85%