Sex in Committed Relationships

Abstract

Sexual behavior is an integral and consequential aspect of intimate relationships. In this chapter, we concentrate on understanding the impact of sexual practices on important components of couple formation, maintenance, and devolution. We review sexuality and relationship literature spanning several decades and disciplines to demonstrate specifically what demographic and other factors influence the quality of sex within relationships, how sexuality influences the quality of couples’ relationships, and whether these patterns are constant within and across different kinds of committed couples. Because the definitions of “commitment” and “relationships” are constantly redefined by both researchers and the couples themselves, we also address the literature that examines intimacy within less “traditional” contexts such as dating and less widely understood semi-committed relationships.

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1 Introduction

Sexual behavior is an integral and consequential aspect of intimate relationships. In this chapter, we concentrate on understanding the impact of sexual practices on important components of couple formation, maintenance, and devolution. We review sexuality and relationship literature spanning several decades and disciplines to demonstrate specifically what demographic and other factors influence the quality of sex within relationships, how sexuality influences the quality of couples’ relationships, and whether these patterns are constant within and across different kinds of committed couples. Because the definitions of “commitment” and “relationships” are constantly redefined by both researchers and the couples themselves, we also address the literature that examines intimacy within less “traditional” contexts such as dating and less widely understood semi-committed relationships.

Why limit the focus of our review to sexual behavior within the context of the committed relationship? Of course the first reason is because the committed couple is the central reproductive and socializing building block of most, if not all, societies. What creates solidarity, or disillusionment, and potentially abandonment, has huge consequences for culture and government. It is also true, however, that while sexuality is not restricted to couples, the vast majority of sex still occurs within committed couples. Indeed, for most heterosexual and same-sex couples, sex is anything but a rare or occasional occurrence. For example, Blumstein and Schwartz (1983) found that approximately 46% of married individuals, 38% of cohabiters, 41% of gay men, and 35% of lesbians who were coupled for at least 2–10 years reported engaging in sex between one and three times per week. Likewise, relative to non-partnered individuals, heterosexual women and men who live together in marriage or cohabitation are about twice as likely to have sex two or three times a week (Laumann et al. 1994; Michael et al. 1994). We also include in this chapter couples that live in a more ambiguous state of commitment than the above studies document. They are in a special section of this chapter because their behavior exists in a different context, and generally, involves different interpersonal negotiations. Further, the vast majority of childbearing still takes place within the context of the committed relationship and so these latter adult alliances, often fleeting in nature, have been less intensively researched

We do, however, discuss diverse kinds of couples who have varying degrees of commitment. A recurrent theme in our chapter is that sexual behavior is different depending on what kind of couple is being studied, and the impact of that behavior on sexual satisfaction and relationship satisfaction also varies. To be sure, the literature suggests a few universal principles: for example, in general, sex strengthens the bonds of relationships. However, the motivations for sex, how often couples have sex, and the consequences of sex vary by a host of demographic factors including one’s gender, age, sexual orientation, position in the life course, as well as many contextual factors such as living arrangements. Thus, we address research on a variety of couple types and the circumstances that may define or constrain their sex lives.

Whenever possible we take a comparative perspective by summarizing key international literature on sexuality in committed relationships. Unfortunately, there is very little comparative literature published in English on many of our topics. Very few studies use global data sets with measures of sexual behavior, so we are mostly reliant on single case studies that sample from particular regions. Thus, rather than generalize how certain phenomena may vary across regions and cultures, we usually note existing differences as evidence that there is great variation in sexual behaviors.

We separate our chapter into three sections. First, we review the well-researched studies that consistently come to the same conclusion regardless of the age, gender, sexual orientation or marital status of the population: Having regular sex with a partner is beneficial for relationships. Second, because relationships are dynamic and constantly evolving, we address issues that couples may face as they try to maintain a healthy sex life over the life course. Finally, although every study mentions that the majority of people world-wide hold monogamy (especially female monogamy) to be essential, we address the incidence and relationship effects of both infidelity and negotiated non-monogamy. We also address these same issues about sexuality in semi-committed relationships such as dating and other new forms of commitment. We conclude with what seem to be the most powerful effects of sexuality on relationships (and vice versa) and some suggestions for demographers interested in advancing the demography of sexuality as a subfield.

2 A Note on Couples and Units of Analyses

The study of the sexual life of couples has intensified in recent decades. Many scholars now rely on large nationally representative datasets to assess how sexual behavior affects relationship well-being and how qualities of the relationship affect couples’ sex lives. Although the research questions are aimed at understanding the well-being and behavior of the couple, it is somewhat ironic that most large, nationally representative datasets rely on the individual as the unit of analysis. For example, studies that are frequently used to address couples’ sexuality such as the National Health and Social Life Survey (NHSLS), the General Social Survey (GSS), and the National Survey of Family Growth (NSFG), rely solely on the individual as the unit of analysis. Researchers must infer that responses regarding sexual frequency, sexual satisfaction, and relationship well-being apply also to the respondent’s sexual partner. This is problematic because sex is a relational act that nearly always occurs in the dyadic context. Important information may be lost or obscured when one respondent must report on behalf of the dyad. Questions about how one partner’s behavior affects the other partner’s behavior or well-being are particularly error-prone using individual-level data. This may be why some authors call for a relational approach that focuses on both the individual and the dyad as units of analyses (McKinnney and Sprecher 1991; Weiderman 2004).

Despite the tendency for researchers to rely on the individual as the unit of analysis to examine couples, some important datasets have examined sexuality at both the individual and couple level. Most notably, Blumstein and Schwartz (1983) surveyed 4,314 heterosexual married and cohabiting couples, as well as 969 gay male and 788 lesbian couples. Separate interview questionnaires were sent to each couple allowing both partners to respond to an identical list of questions. A subset of 300 couples were interviewed separately and subsequently interviewed with both partners present. By privately interviewing partners, researchers were able to obtain information that may not have been divulged had the other partner been present. By interviewing the couples with both partners present, the researchers were able to document the couple’s interaction. For example, the researchers were able to record the couples as they attempted to solve a number of fictional problems that are common to committed relationships. This approach allowed the researchers to better gauge how interpersonal communication strategies are associated with relationship and sexual well-being. Since then, other researchers have approached the study of sexuality among heterosexual and same-sex couples using similar, relational strategies (see Peplau et al. 1997; Veroff et al. 1995). However, couples studies using this strategy are still uncommon.

Although we include some results derived from large datasets that use couples as the unit of analysis, we advise cautious interpretation of the data. Most statistical techniques assume that a sample of the population consists of independent observations, regardless of the designated unit of analysis. Each observation is usually assumed to be unique and independent of all other observations. However, when one includes both partners in an analysis of couples, the observations are no longer independent, and dependent observations violate the assumptions inherent in many statistical techniques (see Kenny 1988). Thus, while datasets that include both partners may help us better understand dyadic relations and increase statistical power, interpretation of those data should take the above methodological challenges into account.

3 The Importance and Incidence of Sexuality in Committed Relationships

3.1 Sexual Well-Being and Relationship Well-Being

Aside from some small, mostly psychological studies, there was a paucity of sexuality research on couples before the 1970s. Blumstein and Schwartz’s (1983) American Couples Survey was the first large-scale survey study to systematically look at the connection between sexual satisfaction and relationship well-being in a diverse sample of committed couples. This connection between sexuality and relationship satisfaction in married, cohabiting, and same-sex couples was further explored in Laumann and colleagues’ (1994) nationally representative National Health and Social Life Survey (NHSLS). Other conterminous studies that relied on large national surveys arrived at the same general conclusion: happy couples have frequent sex and satisfying sex lives (Byers 2005; Costa and Brody 2007; Deenen et al. 1994; Gossman et al. 2003; Henderson-King and Veroff 1994; Kurdek 1991; Peplau et al. 1997, 2004; Sprecher 2002; Yeh et al. 2006). Several international studies spanning nearly every developed region of the world have also found strong links between sexual satisfaction and relationship quality which lends credence to the universality of the association (Barrientos and Paez 2006; Guo and Huang 2005; Haavio-Mannila and Kontula 1997; Renaud et al. 1997).

Same-sex relationships were even more neglected before the late 1970s and early 1980s. It was not until 1983 when the Blumstein and Schwartz study first used survey data to systematically analyze same-sex committed unions. Their data indicated that sexual activity was just as important for relationship satisfaction in gay couples as it was in heterosexual couples (Blumstein and Schwartz 1983). This finding was replicated by a number of smaller studies since the 1990s (Kurdek 1991, 1994; Peplau et al. 1997, 2004). The same conclusion has been validated in two recent studies based on internet samples of lesbian women (Henderson et al. 2009; Tracy and Junginger 2007); these researchers also found that pleasure during sex, heightened arousal, and overall sexual satisfaction were positively associated with relationship satisfaction.

Most studies that document the association between sexual satisfaction and relationship satisfaction measure relationship well-being as a subjective assessment of the relationship at the time of the interview. The association remains robust, however, when researchers examine relationship well-being in a more objective manner by observing relationship stability or relationship durability. A handful of longitudinal studies have found a significant negative association between sexual satisfaction and either thoughts of ending the relationship or the dissolution of the relationship itself (Edwards and Booth 1994; Veroff et al. 1995; White and Keith 1990). More recently, Yeh and colleagues (2006) studied 283 midlife heterosexual couples over a period of 5 years, and found that early reports of sexual satisfaction predicted later changes in marital stability. The authors found that sexual satisfaction led to stability through its positive effect on marital satisfaction. This study was limited to rural, married couples who had previously been together for many years, but studies of urban couples and studies using random samples have arrived at similar conclusions (e.g. Blumstein and Schwartz 1983; Laumann et al. 1994).

Which individual characteristics and relationship types are most likely to lead to a satisfied sex life? The short answer to the question is that, by and large, most partnered individuals are satisfied with their sex lives. However, the frequency of sexual satisfaction varies dramatically by a few key demographic factors. Both Blumstein and Schwartz (1983) and Laumann and colleagues (1994) found that individuals who had sex within the context of a committed relationship were more likely to report satisfaction with their sex lives. Figure 8.1, adapted from Laumann and colleagues’ NSHSL (1994) data, demonstrates the strong association between sexual satisfaction and couple type. Specifically, about 88% of married, monogamous couples reported being very or extremely sexually satisfied followed by about 84% of cohabiters and 78% of singles. The researchers noted that this finding defies the stereotype of highly satisfied and sexually manic singles that dominates much of popular media (see Michaels et al. 1994).

Fig. 8.1

Percent “very” or “extremely” sexually satisfied with sexual relationship by relationship status (Source: Laumann et al. (1994) using NHSLS 1994)

The same study, however, did reveal a satisfaction gap by gender and age. Figure 8.2 presents the proportion of respondents who reported being extremely physically satisfied with their relationship. While women appear to be slightly less satisfied with their sex lives at all age groups, the satisfaction gap is more pronounced for women of older ages. The authors speculated that some of the discrepancy may be accounted for by different biological and cultural processes; specifically, the fact that menopause affects many women’s sexual interest and satisfaction, and the cultural devaluation of older women’s sexuality may affect their sexual self-image (see also Koch et al. 2005).

Fig. 8.2

Percent extremely physically satisfied with relationship (Source: Laumann et al. (1994) using NHSLS 1994)

The quality of sex is not the only aspect of physical intimacy that affects couples’ satisfaction with their relationship. The quantity of sexual acts (usually measured as coital frequency) is also associated with relationship well-being. Perhaps unsurprisingly, sexual frequency is strongly correlated with sexual satisfaction (Blumstein and Schwartz 1983; Fisher 2009; Greely 1991; Haavio-Mannila and Kontula 1997; Laumann et al. 1994). This finding is consistent when comparing married couples, cohabiting couples, and same-sex couples (Blumstein and Schwartz 1983; Deenen et al. 1994; Peplau et al. 2004; Richter et al. 2003). To be sure, the correlation may be driven by the fact that couples may have more frequent intercourse if the sex is satisfying (Harvey et al. 2004). However, Schwartz and Young (2009) noted that an alternative explanation may be that frequent sex gives partners the opportunity to explore each others’ desires and increase the likelihood of orgasm. Longitudinal studies that examine the effects of changes in sexual frequency and sexual satisfaction over time and how changes affect relationship well-being may shed more light on the causal order.

Some studies have examined the effects of sexual frequency on relationship well-being, apart from its effects on sexual satisfaction. Call and colleagues (1995) utilized the National Survey of Families and Households (NSFH) to examine the incidence and frequency of sexual intercourse in a large sample of married couples. The authors found that aside from the aging process, sexual frequency was most strongly associated with marital satisfaction. This finding appears to hold true for same-sex couples. Using two waves of longitudinal data, Balsam and colleagues (2008) compared 176 partnered gay men, 397 partnered lesbians, and 110 married heterosexuals and found that sexual frequency at time one was a significant predictor of relationship quality at time two. However, the positive effects of sexual frequency on couples’ relationship well-being may not be as universal as the effects of sexual satisfaction. Some researchers who have found weaker sex frequency effects in other regions of the world suggest that sexual frequency may be less relevant in cultures that do not openly emphasize sexuality as a key component of relationships (Knodel et al. 2007).

It is important to note, however, that sexual frequency is not constant through the duration of relationships. Virtually all couples—heterosexual or same-sex, cohabiting or married—experience a decline in sexual frequency over their years together (Blumstein and Schwartz 1983; Brewis and Meyer 2005; Call et al. 1995; Gossman et al. 2003; James 1981; Johnson et al. 1994; Klausmann 2002; Udry 1980). Fortunately for committed couples, most studies find that declines in sexual satisfaction do not necessarily follow declines in sexual frequency, suggesting that while the initial novelty of the “honeymoon phase” may eventually fade, most partners still enjoy their sex lives (but see Klausmann 2002; Liu 2002). Thus, it appears that although sexual frequency and sexual satisfaction are strongly associated, to some degree both operate differently in the context of the relationship.

While it has been firmly established that regular and satisfying sex is beneficial for both heterosexual and same-sex relationships, not all groups behave or benefit equally. The incidence of couples’ sexual interaction and the impact of those interactions vary depending on the population studied. Key demographic variables such as gender and sexual orientation of the partner have a significant influence on what kinds of sexual behaviors occur, as well as the consequences of these behaviors, in different kinds of intimate relationships.

3.2 Variation in the Incidence and Effects of Sexuality in Different Types of Committed Couples

Even in quite diverse samples of couple types, few differences in sexual behavior or sexual satisfaction exist by race, ethnicity, income, occupation, and education. However, as we discuss below, several researchers have found that certain social and demographic characteristics do matter in determining how sex affects relationships. In particular, respondent’s gender, sexual orientation, and whether the couple is cohabiting versus married explain some of the variation in sexual behaviors and the impact of sex on relationships. While these variables by no means invalidate the positive relationship between frequent and satisfying sex lives and satisfying relationships, they certainly add complexity to our understanding of the role of sexuality in committed relationships.

3.2.1 Differences by Gender

While women and men both benefit from maintaining a frequent sex life, most research suggests that sex is more central to the health and maintenance of the relationship for men. When asked to report their ideal sexual frequencies, men report higher frequencies than women (Richter et al. 2003). Also, virtually every study conducted has shown that the positive benefits of sexual satisfaction on relationship well-being are stronger for men than for women. For example, in an analysis of premarital couples, Sprecher (2002) found that sexual satisfaction was negatively associated with ending the relationship for men, while for women relationship satisfaction was more strongly associated with relationship dissolution. In addition, changes in sexual frequency may be more closely associated with sexual satisfaction for men relative to women (McNulty and Fisher 2008). There also appear to be gender differences in the effects of different types of sexual contact; research suggests that genital contact is more important for men’s perceptions of relationship satisfaction compared to women (Fassinger and Morrow 1995; Loulan 1988). We do not mean to imply that, for women, sexual satisfaction and sexual frequency are not important aspects of relationships, it is just the case that the positive effects of a healthy sex life appear to be stronger for men.

Many researchers try and parse out biological versus contextual and cultural variables as the explanation for these gender differences. To date, there is no definitive answer. Still, there are data that lead us to believe that social forces such as differential socialization may account for such consistent gender differences in the desire for, and impact of, sexual behavior. A study by Carpenter and colleagues (2009) suggested that, for women, simply believing in inherent gender differences regarding women and men’s sexual roles lowered their satisfaction with sex. Also, Blumstein and Schwartz (1983) hypothesized that the association between sexual satisfaction and relationship satisfaction may be weaker for women because women have absorbed the widespread cultural belief that women want sex less, can control their sexual impulses more, and that it is inappropriate for a woman to overemphasize sex in a relationship. It will be interesting to see if the changes in young women’s sexual lives in uncommitted relationships (more sexual partners, “hooking up,” etc.) will make sexual satisfaction more important for relationship satisfaction in committed relationships in the future (see Bogle 2008).

3.2.2 Differences by Couple Type

Despite the fact that cohabitation appears to be an increasingly popular context for committed relationships, there are still differences in the sexual lives of married and cohabiting couples. Figure 8.3, adapted from Laumann and colleagues’ (1994) data, shows various coital frequencies broken down by couple type and gender. Although married couples and cohabiters appear similar in terms of sexual frequency, both male and female cohabiters are more likely to report having sex two to three times a week relative to their married and single counterparts. Additionally, estimates from the NSFH suggest that cohabiters have a mean of 11–13 sexual acts per month, while their married couples have a mean of 6.3 times per month (Call et al. 1995). Additional studies have replicated this finding using large, nationally-representative datasets (Rao and DeMaris 1995; Yakibu and Gager 2009). However, as the data in Fig. 8.1 imply, it is rather intriguing that even though cohabiters have more frequent sex than married couples, they are less likely to be satisfied with their sex lives (Blumstein and Schwartz 1983; Laumann et al. 1994).

Fig. 8.3

Frequency of sex in the past 12 months by gender and relationship status (Source: Laumann et al. (1994) using NHSLS 1994)

This is an especially important finding because the preponderance of studies show that sex is more important to cohabiters than it is to married couples. Blumstein and Schwartz (1983) found that declines in sexual frequency were especially problematic for cohabiting couples in terms of relationship well-being. Similarly, Yakibu and Gager (2009) examined two waves of the NSFH and found that cohabiters, compared to married couples, were much more likely to separate over time, but a higher sexual frequency reduced the likelihood of relationship dissolution. Blumstein and Schwartz (1983) hypothesized that because cohabitation represents a less recognized and less committed context relative to marriage, declines in sexual frequency may signal to one partner that the other may be disinterested with the relationship. Schwartz and Rutter (1998) also argued that many cohabiters, especially those who are cohabiting as a trial run for marriage, may see cohabitation as an “audition” before deciding on marriage or some kind of deeper commitment. In other words, partners may view frequent and satisfying sex in cohabitation as a key predictor of what sex would be like in marriage. Yakibu and Gager (2009) pointed out that cohabiting unions are more likely to be based on immediate gratification and extrinsic rewards—an argument that is consistent with the common finding that cohabiters are, on average, more individualistic-oriented than adults who transition directly into marriage.

3.2.3 Differences by Sexual Identity

While there has been an increase in the research on same-sex couples, the 1983 “American Couples” survey by Blumstein and Schwartz remains one of the only large-scale studies to include a sample of paired gay men and lesbians. Laumann and colleagues (1994) included information about same-sex behavior and identities in the NHSLS, but couples were not studied and the resulting sample was far too small for any meaningful analysis. Thus, most of our recent knowledge about same-sex couples is derived from small convenience samples (see Kurdek 1991, 1994; Peplau et al. 1997, 2004).

Still there seem to be some consistent results that are replicated in both large and small studies. To begin with, same-sex couples are more similar to heterosexual couples than they are different. Same-sex couples appear to be equally as likely as their heterosexual counterparts to report being satisfied with their sex lives (Kurdek 1991) and also benefit from having satisfying sex lives (Blumstein and Schwartz 1983; Cohen et al. 2008; Tracy and Junginer 2007). When it comes to quantity of sex, however, there are sharp distinctions between same-sex and heterosexual couples. Blumstein and Schwartz (1983) reported that gay men had the highest frequencies of sex (all genital behaviors), while lesbians had the lowest frequencies of sex (all genital behaviors). Figure 8.4, adapted from Blumstein and Scwhartz’s (1983) American Couples data, displays the proportion of couples engaging in intercourse three or more times a week, broken down by couple type for various lengths of relationship duration. Gay male couples appear more likely to have sex three times a week or more compared to all other couple types, while lesbians are the least likely to report having sex three or more times a week across all stages of their relationships. A recent, well-designed study not only found similar results, but was able to add another dimension to the analysis—couple’s commitment level. Because Vermont is one of the few states to allow same-sex civil unions, Solomon and colleagues (2005) were able to use registration records to compare a sizeable sample of same-sex couples who opted for civil-unions (presumably high-commitment) to same-sex cohabiting couples (presumably low-commitment) and the married heterosexual siblings of the same-sex couples (to control for similar background characteristics). With regard to lesbian couples, the authors replicated Blumstein and Schwartz’s (1983) survey of nearly three decades earlier: lesbians at both stages of commitment had significantly less sex with their partners than did heterosexual women and the other couple types. Solomon and colleagues, however, found that gay men’s frequencies were not distinguishable from heterosexual men, regardless of whether they were in a civil union or not. Thus, it is unclear whether gay men still have more frequent sex compared to other couple types, and it appears that level of commitment (as best approximated by obtaining a civil union) is unrelated to sexual frequency for gay men.

Fig. 8.4

Frequency of sex three times a week or more by partnership type and relationship duration (Source: Blumstein and Schwartz (1983) using the American Couples Survey)

Researchers have also speculated about why lesbians report significantly lower sex frequencies relative to other couple types. Blumstein and Schwartz (1983) noted that heterosexual women in committed couples had more sexual activity and ranked it as more important than did their lesbian counterparts. The authors speculated that the presence of a male may alter the nature of the sexual relationship because men are socialized to initiate sex more and also place a greater emphasis on the importance of coital frequency. The fact that the absence of a male would result in less sexual frequency—especially coital frequency—would be consistent with the finding that women may find genital sexuality less important than men (Fassinger and Morrow 1995; Loulan 1988). An additional factor to consider would be that perhaps lesbians have more kinds of sex that we do not tabulate (most research looks primarily at coital frequency) and so lesbian sexual behavior may be inadequately represented in models that only examine coital frequency. There is certainly evidence that lesbians rely on a wide variety of sexual techniques apart from actual penetrative sexual behavior (Coleman et al. 1983; Lever 1995; Nichols 2004). For example, lesbians engage in more kissing and cuddling than other kinds of couples and their sexual play has been described as “more fluid” compared to heterosexual women (Nichols 2004). Furthermore, some evidence calls into question the claim that lesbians might be leading unfulfilling sex lives. To begin with, it is interesting to note that while gay men may report high sex frequencies, at least one study suggests that lesbians are more likely to report higher levels of sexual satisfaction (Bryant and Demian 1994). Also, a 3 year follow-up of the Vermont study found that sexual frequency was an important predictor of relationship satisfaction for lesbians, but not for heterosexual women. This suggests that while lesbian couples may not engage in coital frequency as often as other couple types, regular sexual behavior is still an important source of relationship stability (Balsam et al. 2008).

3.3 The Effects of Relationship Well-Being on Sexual Behavior in Committed Relationships

So far our review has been focused primarily on the effects of sexual behaviors on committed relationships. However, because most of our research comes from large, cross-sectional data sets, researchers usually interpret their results using the language of association rather than causation. While it true that studies suggest that healthy and frequent sex must, at the very least, partially cause relationships to feel more rewarding, we cannot entirely rule out the possibility that happy couples are simply more likely to report more frequent and fulfilling sex lives. Unfortunately, cross-sectional data cannot establish what occurs first—so we do not know for sure whether good sex leads to a satisfying relationship or a satisfying relationship leads to good sex. In this section we review several well done studies that suggest that relationship characteristics do in fact exert their own independent effects on couples’ sexual well-being.

When couples are emotionally invested in each other and share similar goals, it is reasonable to hypothesize that they may have more enjoyable sex lives. Young and colleagues (1998) examined a group of 797 married couples and found that of all the possible correlates of sexual satisfaction (including orgasm and sexual frequency), overall satisfaction with the marriage and satisfaction with non-sexual aspects of the relationship, such as shared goals, respect, and recreational companionship, were the most strongly associated. A study that examined the motivations for sexual behavior found that when cohabiting and married couples have sex in order to express their love, they were more likely to report deriving physical pleasure from the act (Waite and Joyner 2001). While it is true that these studies do not imply causality, the correlation between non-sexual aspects of the relationship lends considerable evidence to the possibility that the state of couples’ relationships may influence their sexual satisfaction.

The connection between relationship quality and sexual pleasure seems to be especially important for women. Basson’s (2000) model of female sexuality suggests that many women rely on mental and relational stimuli for sexual arousal. The author asserted that the lack of such subjective, relational arousal often explains women’s reports of low sexual desires—reports that are often mislabeled as a sexual dysfunction (Basson 2000; Basson et al. 2003). Several studies confirm the validity of this model for large numbers of women. For example, Bridges and colleagues (2004) analyzed a nationally representative survey of 2,632 women and found that feeling connected to one’s partner was associated with sexual satisfaction. Some studies go further to suggest that women must be satisfied with their relationship to enjoy sex at all (Fenney and Noller 2004; Metz and Epstein 2002). Other research has demonstrated that women in relationships characterized by egalitarian decision-making processes are more likely to have fulfilling sex lives (Blumstein and Schwartz 1983; Brezsnyak and Whisman 2004), and are more willing to experiment with new sexual positions (Blumstein and Schwartz 1983).

We are not suggesting, however, that relationship satisfaction is unimportant for men’s sexual lives. On the contrary, relationship satisfaction is a significant predictor for men’s sexual satisfaction; it is just not as central to their sexual well-being (Lawrence and Byers 1995). In fact two studies suggest that both gay men (Cove and Boyle 2002) and heterosexual men over the age of 50 (Schiavi 1999) are more likely to enjoy sex if they perceive their relationship as going well. Ultimately, while there are gender differences in the strength of the effect of relationship quality on sexual satisfaction, the differences are only relative. Men, like their female counterparts, are happier with their sex lives when they are content with their love lives.

When we break “a good relationship” into its component parts, communication emerges as one of the most important factors to take into consideration (Schnarch 2009). The research literature has consistently associated a couple’s communication skills with sexual satisfaction. Partners who communicate regularly about their relationship and their sex lives report higher levels of sexual satisfaction and sex frequency (Byers 2005; Gossman 2003; Mackey et al. 2000, 2004; Purnine and Carey 1997). Communication skills may be especially important for couples who face constraints on their sexual lives. Good couple communication appears to increase non-sexual physical intimacy between partners when disruptions (such as the presence of young children) decrease sexual satisfaction (Alhborg et al. 2005). But good couple communication may have its limits. A study by MacNeil and Byers (1997) found that although sexual and non-sexual communication were positively associated with sexual satisfaction, the presence of both types of communication did not reduce the negative effect of partners’ real or perceived concerns about sexual intimacy on sexual satisfaction. However, the authors acknowledged that two of their samples’ most commonly reported sexual concerns were disinterest in sex and trouble getting aroused, and good communication may still be beneficial for couples with more serious sexual problems. Indeed, as we discuss in a later section, good communication and partner support appears to mitigate the harmful effects of serious sexual impairments on reported levels of sexual satisfaction.

The mundane aspects of relationships also affect sexual satisfaction. The division of household tasks can affect sexual satisfaction and sexual frequency. Some recent media reports have suggested that men who assist in housework get more sex from their partners, and suggest that women reward men’s egalitarian behavior with increased sexual frequency. Supporting the claim, Rao and Demaris (1995) found that women who reported an egalitarian division of household labor were more likely to report higher sexual frequencies. However, a study by Kornrich and colleagues (2013) casts doubt on the association between egalitarianism and sex. Using data from Wave II of the NSFH, the authors found just the opposite of the egalitarian-men-get-more-sex hypothesis. Couples who divided their housework tasks in a more traditional fashion reported higher sex frequencies than their egalitarian counterparts. The authors argued that participating in appropriately gender-typed activities may be an effective way to express heterosexual desire in traditional couples, while egalitarian partners do not receive “extra credit” for being equitable in their household duties. Egalitarianism, while much prized by partners who are ideologically and emotionally committed to sharing household chores and childrearing, may not be especially erotic. In a study of over a hundred egalitarian marriages, Schwartz (1995) found that more than a few partners reported an unexpected reduction in sexual frequency precisely because the couples related as close as siblings or platonic friends. However, while egalitarianism may be associated with a decline in sexual frequency, it may still be beneficial for sexual satisfaction; a recent study of a sample of 60 married couples found that egalitarian couples were more likely to be satisfied with their sex lives (Breznyak and Whisman 2004). The authors speculated that couples who worked at maintaining equality in their relationships extended their egalitarian behaviors to ensure that both partners were equally satisfied in the bedroom.

In sum, just as there is much evidence suggesting that sexual satisfaction leads to relationship satisfaction, there is ample evidence suggesting that causality operates in the opposite direction—non-sexual characteristics of the relationship, such as relationship satisfaction, affect sexual well-being.

3.4 Summary: Sexual Frequency, Sexual Satisfaction, and Relationship Well-being

One of the main benefits of maintaining committed relationships—a benefit that is not lost on cohabiting couples—is the relatively unrestricted access to a regular sex partner. There is a general consensus that frequent and satisfying sex is critical for the maintenance of committed relationships—both for heterosexual and same-sex couples. Of course, the strength of the effects of sexual satisfaction on relationship satisfaction is not uniform across all populations (i.e. women’s lower prioritization of sex in their relationship). Furthermore, the primacy of sex within committed relationships may vary across groups (i.e. cohabiters vs. married and gay men vs. lesbians). The picture becomes even more complicated when we consider that relationship characteristics such as relationship well-being, communication, and egalitarianism are likely to exert their own effects on sexual behaviors. Nonetheless, the past 30 years of research on sex and couples has firmly established the centrality of sex in the maintenance of relationships. This static approach however, does not recognize that relationships change over the life cycle: people age, relationships mature, and both carefully planned and unexpected constraints to intimacy emerge as couples navigate their lives together. It is to these life changes and constraints that we now direct our attention.

4 Sexual Constraints Over Time in Committed Relationships

Opportunities for sex are partially constructed by our immediate environment, our cultural and legal systems, and our individual health, options, and values. Such contextual and individual-level characteristics place constraints on sexuality within committed relationships, and these constraints help to explain much of the within-group variation that we observe when studying couples and their sex lives. In this section we review research that has examined individual-level, relationship-level, and contextual constraints that affect couples’ ability to maintain satisfying sex lives throughout their relationship.

4.1 Relationships Across Time: The Effects of Aging and Duration on Sexual Intimacy

We have indicated that both age and the duration of relationships affect sexual frequency, which in turn, can affect both sexual and relationship satisfaction. It is, however, useful to understand more than these gross associations. In particular, since western populations are aging, it is important to know the differential impacts of each decade of life across the duration of a relationship. We believe it is fair to say that no one demographic trend has influenced sexuality within committed relationships more than the emergence of a large older adult population driven by the baby boom. The youngest boomers are in their late 40s and the leading edge of the baby boomers is just turning 65. In addition, the Baby Boom cohort is expected to live longer than any adult population in U.S. history. Two possible hypotheses about sexuality in this population compete with each other: on one hand, aging has a biological and irreversible impact on the body, brain, and endocrine system and so the Baby Boomers will have less sex as they age as has been observed with older generations. One the other hand, the Boomers are aging in a very different context than previous generations. The Boomers’ experience with the Sexual Revolution, the greater discussion about sexuality in our culture since the 1960s, and the new technologies for extended sexual capability (such as erectile dysfunction drugs) could make the Boomers more sexually interested and active than the generations before them. We will take a close look at data on sexuality and aging and summarize the results of studies by age groups.

Traditionally, research has indicated that age is one of the strongest predictors of sexual frequencies for all couple types. While the effect of age on sexual frequency is most pronounced for the older-age couples, age differences in sex frequencies first emerge when adults enter their middle-age years. Laumann and colleagues (1994) found that mid-aged individuals were the least likely of the age groups to report having sex two or three times a week. However, the NHSL sample did not include older-aged adults, and the survey did not distinguish between single adults and single adults with dating partners. Fortunately, this is done in the nationally representative study conducted by the American Association of Retired Persons (AARP), a national membership group for people over 45, every 4 or 5 years since 1999 (Fisher 2009). Figure 8.5, based on the most recent wave of the AARP study, summarizes sexual frequencies (having sex at least once per week) by age categories and respondent’s gender. The figure clearly demonstrates a steady decline in sexual frequency as adults age, and in general this decline is more pronounced for women compared to men. Comparing these data to previous cohorts, the AARP study does not show an increase in sexual behavior for the boomers compared to previous generations of the same age (in fact, the study shows a slight decrease in sexual activity in all age groups, perhaps accounted for by increased reported stress, particularly financial stress, in each age group).

Fig. 8.5

Percent having sex at least once a week by age and gender (Source: AARP Survey of Midlife and Older Adults 2009)

The recent AARP data also emphasize the importance of commitment and partner presence for older adults’ sex lives. Contrary to Laumann and colleagues’ (1994) data, the AARP data suggest that when the sample is restricted to older adults, single adults who are in dating relationships appear to have more sex than married couples. In Fig. 8.6, we use the recent AARP data to show various categories of sexual frequency by relationship status for the entire older adult sample. Specifically, 48% of dating older adults reported having sex at least once a week, compared to 36% of married older adults and 3% of singles who are not dating. The figure demonstrates the striking negative effect of lacking a partner on sexual frequency; nearly 90% of the single older adults in the sample who lacked a committed partner reported not having sex in the past 6 months. In addition, for older adults, it appears that sexual satisfaction follows a similar pattern to sexual frequency. About 60% of dating older adults reported being extremely or somewhat satisfied with their sex lives, compared to 51% of married older adults and 19% of single older adults who were not dating (Fisher 2009). However, it is important to note that small sample sizes might have affected the results—only 145 adults in the sample reported that they were dating. Overall, there seems to be some evidence that while age is still an important predictor of sexual frequency, much of the decrease in sexual behavior among older cohorts has been due to a lack of a partner or perhaps boredom in a long-term relationship, rather than a lack of desire or capability.

Fig. 8.6

Frequency of sex by relationship status (Source: AARP Survey of Midlife and Older Adults 2009)

Other large, nationally-representative studies have also found that age negatively affects couples’ sexual frequency (Call et al. 1995; Mariglio and Donnelly 1991; Rao and Demaris 1995). Call and colleagues found that while 83% of those aged 50–54 and 57% of those aged 65–69 reported having sex with their married partner in the last month, only a little over one-fourth of those 75 or older reported having sex with their spouse during the previous month. In addition, the mean sexual frequency for spouses of the 75 and older group was only once a month. However, when the authors limited their analysis to the sample of adults 75 or older who were sexually active, the average frequency of sex shifted from once a month to three times a month.

As we indicated above, gender appears to moderate the effects of age on older adults’ reported sexual frequencies. Laumann and colleagues (1994) found that of adults aged 40–49, 27% of men and 20% of women reported having sex two to three times a week. Similarly, for adults aged 50–59, 20% of men and only 12% of women reported sexual frequencies of two to three times a week. When we examine the number of older adults who reported not having sex within the past year, the gender differences become even more pronounced; 30% of women in the 50–59 range and only 11% of similarly aged men reported having no sex within the year. The AARP data also confirm these differences; Fig. 8.5 clearly demonstrates that older men, by and large, are more likely to engage in intercourse, and this pattern generally holds regardless of how sexual frequency is specified (i.e. once a week versus once a month).

What explains the gender difference in sexual frequency for older adults? First, the higher mortality and incarceration rates of men suggest that mid-aged and older-aged women have a declining pool of same-aged, eligible partners. Furthermore, in an already declining pool of eligible mates, it has been argued that a combination of sexism and ageism exacerbate women’s ability to find sexual partners (Carpenter et al. 2009). It is culturally more acceptable for men to partner with younger women while younger men who have sex with older women often have their motives impugned. While there has been recent glamorization (and caricature) of Cougars (older women who are attractive but predatory), in general older women are viewed as less attractive at an earlier age relative to men. According to these arguments, sexual frequency should be the lowest for the oldest groups of non-married women. Matthias and colleagues (1997) provided strong evidence for these arguments using a Los Angeles-based sample of 1,216 older-aged adults (70 or older). The authors found that younger age and education were the strongest predictors of sexual frequency for men, but for women, the strongest predictor was marital status. Indeed, married older-aged women were nearly 24 times as likely to have had sexual activity within the past month compared to their non-married counterparts.

Despite the undeniably strong evidence that age negatively affects sexual frequency for both women and men, it is possible to overstate the effects of age by confounding age and duration of the relationship. Older couples are more likely than younger couples to have been with their partner for a longer period of time simply because they have been alive longer. Many studies have documented a steady decrease in sexual frequency as relationships progress regardless of what age group is examined (Blumstein and Schwartz 1983; Brewis and Meyer 2005; Call et al. 1995; Edwards and Booth 1994; Gossman et al. 2003; James 1981; Johnson et al. 1994; Klausmann 2002; Udry 1980). Relationship duration is also negatively associated with sexual frequency for cohabiting couples (Blumstein and Schwartz 1983; Fisher 2009; Gossman et al. 2003; Stafford et al. 2004). Despite this evidence, age appears to be a better overall predictor of sexual frequency than duration, at least for married heterosexual couples. However, Call and colleagues (1995) found that duration only appears to take a dramatic toll during the first year or two of marriage; subsequent decline in sexual frequency is much more gradual and moderate. This drop in sexual frequency probably occurs as couples transition from the “honeymoon phase” into a more routine sexual schedule. Other studies have also found relationship duration to be a more important predictor of frequency during the early years of marriage and less important in the later years—the years when age effects are more likely to take hold (Edwards and Booth 1994; James 1981, 1983). Age, on the other hand, affects couples at each stage of the relationship, and is the single strongest predictor of sexual frequency. Although there is very little research on the effects of age and relationship duration on the sex lives of same-sex couples, there is evidence that age and duration partially explain declining sex frequencies for same-sex couples (Blumstein and Schwartz 1983).

Does the fact that age is commonly the strongest predictor of sexual frequency in American samples suggest that age is universally more important than relationship duration? A large study conducted by Brewis and Meyer (2005) of 91,744 women in 19 developing countries suggests that the effects of relationship duration, as well as both women’s and men’s ages, on sexual frequency may be context-specific. While the observed decline in sexual frequency that occurs as couples age appears to be universal, there is considerable country-level variation regarding whether aging or relationship duration is more important in decreasing sexual frequency. While studies using American samples suggest that women’s age is a stronger predictor of declines in couples’ sexual frequency, this is not the case in all countries, especially Latin American countries. Also of interest, in several countries, most of which were characterized by large Catholic populations, relationship duration did not negatively affect sexual frequency when controlling for the couples’ ages. The authors suggest that trends in earlier pregnancies and the use of abstinence as opposed to contraception as a pregnancy prevention strategy may prolong the sexual novelty of the relationship.

Since age is a major predictor of sexual frequency, what is it about the aging process that causes the decline? Undoubtedly, biology and overall condition of personal and partner health plays a role (Fisher 2009). A review of the literature on the biological aspects of the aging process is beyond the scope of this review. However, a few key biological changes are worth mentioning. In the later years of their lives, women transition through menopause which can make intercourse difficult, uncomfortable, or even painful. For some women, the onset of menopause and accompanying lower sexual desire may negatively affect sexual and relationship well-being (Dennestein et al. 2006; Fisher 2009; Leiblum et al. 2006). Older men also have their share of biological concerns. Men experience a reduction in the production of testosterone which makes it increasingly difficult at older ages to achieve and maintain erections, and lengthens the amount of time it takes to become aroused post-orgasm. Indeed, 23% of the AARP male sample indicated that erectile problems were an important issue (Fisher 2009). But it is important to note that the negative effects of age are not solely due to health issues. When AARP respondents were asked to indicate what personal or social issues impeded their sexual behavior and/or sexual satisfaction, men and women in the AARP study stated personal health, general stress, partner’s health, financial stress, and lack of a partner as the top five social and personal issues that negatively affected their sex life (Fisher 2009).

Social and contextual factors that have a negative impact on older couples deserve more research (for a review see Burgess 2004: pp. 446–448) and it appears that more research will be emerging. As mentioned earlier, recent commercial drugs aimed at increasing sexual interest and ability among older men and women have spurred new research publications and highlighted the existence of a desire for a fulfilling sexual life in gerontological populations. Pharmaceutical companies like Pfizer, `Lilly, Bayer, GlaxoSmithKline, and Boehringer Ingelheim either have produced a sexual performance drug for older adults or have one in development. Grants from these and other pharmaceutical companies for research on sexual desire or sexual dysfunction have become common for both social science and medical researchers.

4.2 Relationships and Life-Course Events: The Effects of Pregnancy, Children, and Employment on Couples’ Sexual Behavior

Sexuality is also affected over the life course by specific events in a couple’s life together. Most couples contend with decisions about marriage, childrearing, and work—all of which impact their sexual and emotional life. Women are particularly vulnerable to the sequencing of life events since they balance pregnancy, being the primary caregiver, and labor force participation with the demands of a committed relationship. Historically, same-sex couples’ life-course trajectories have been much different from heterosexual couples raising young families, but today, with greater civil rights, less prejudice (McVeigh and Diaz 2009), and the likely advent of gay marriage, more same-sex couples are likely to have or adopt their own children, or have children in their household from a previous heterosexual marriage (Baumle et al. 2009). These social factors make it likely that in this millennium, family-related, life-course events will also impact the sexual behaviors of same-sex couples. While most of the relevant life course data in this section comes from studies on heterosexual couples, we assume that similar issues will affect the sexual adjustment of some same-sex couples as well.

At some point over the life course the vast majority of Americans experience the transition to marriage. The transition to marriage usually involves a redefinition of one’s self and the relationship (Berger and Kellner 1964), and this public change of status plus subsequent reductions in autonomy are among the big and broad changes that could impact a couples’ sexual life. Stafford and colleagues (2004) used two waves of the NSFH to see if the transition to marriage or living in a specific type of couple affected sexual frequency. The researchers compared three couple types: couples who transitioned from cohabitation to marriage, couples who did not cohabit before marriage, and long-term cohabiters. While couple type did not explain variations in sexual frequency, for all three types of couples, the passage from time 1 (the first wave) to time 2 (the second wave) had a negative effect on sexual frequency, suggesting that aging and duration were more important predictors of sex frequency than the transition from cohabitation to marriage.

The transition to marriage or some other type of public commitment might also affect the sexual behavior of same-sex couples. Since same-sex legal marriage is still relatively rare, we do not have much data on how this change in status affects the sexuality and overall relationship of those in same-sex relationships. However, the Vermont study of same-sex couples who entered into civil unions is a useful starting point. Much like their heterosexual counterparts, the same-sex couples (both lesbian and gay men) who transitioned into a civil union did not differ in sex frequency compared to the same-sex cohabiting couples (Solomon et al. 2005). Unfortunately, we cannot distinguish whether the transition to a legally recognized union lowered the likelihood of having extra-relationship sex, or if couples who are less likely to have non-monogamous sex self-select into civil unions. In sum, there is little evidence that the transition to a legally recognized status negatively affects sexual frequency independent of other effects, such as relationship duration, for heterosexual and same-sex couples.

While the transition to marriage does not seem to exert a strong effect on couples’ sex lives, pregnancy and the presence of children greatly constrain heterosexual couples’ sexual behavior. Most studies find that couples remain interested in sex throughout the duration of the pregnancy, but as the pregnancy progresses sexual frequency declines and usually does not return to its pre-pregnancy levels (Ahlborg et al. 2005; Bartellas et al. 2000; Borgen 1991; Elliot and Watson 1985; Hyde et al. 1996; James 1981; von Sydow 1999). This is likely due to a combination of factors but the literature on pregnancy concentrates on changes in women’s perceived body image, fear of harming the fetus, physical discomfort because of weight gain, or increased pain during intercourse because of estrogen-related loss of lubrication. Several international studies conducted in diverse settings such as Kuwait (Bustan et al. 1995), Hong Kong (Haines et al. 1996), Nigeria (Adinma 1995), New Zealand (Oruc et al. 1999) and Pakistan (Naim and Bhutto 2000) also have found that sexual frequency declines as pregnancy progresses. These international studies suggest that declines in sexual frequency during pregnancy are probably universal. However, the reasons for the decline may vary by region and culture. For example, some of the women in studies that were conducted in countries that could be reasonably classified as sexually conservative were more likely to report harming the fetus as a reason for engaging in less sex with their partner.

While most of our information regarding pregnancy and sexuality is gathered from small, convenience samples, two large-scale studies are particularly worth mentioning. Hyde and colleagues (1996) conducted a longitudinal study of 570 pregnant women that began during the fifth month of their pregnancy and ended 1 year postpartum. During the pregnancy, couples’ average sexual frequency ranged between four and five times per month. However, the couples experienced a heavy drop in frequency postpartum; during the first month postpartum, most couples had little to no sex. The couples did not resume regular intercourse until between 4 and 5 months postpartum and, when they did so, the rate resembled the frequency during pregnancy rather than the couple’s pre-pregnancy frequency. Ahlborg and colleagues (2005) conducted a large, cross-sectional study of 820 Swedish parents in their early 30s at the point of 6 months after childbirth. The authors found that couples did not begin having regular sex until 3 months postpartum—again, at a rate lower than pre-pregnancy. When asked why they did not engage in more regular sexual activities, 47% of mothers and 38% of fathers reported that fatigue was a major issue. It is important to note that when asked about relationship satisfaction, the parents’ responses were consistent with most studies: The parents reported high levels of relationship satisfaction immediately after childbirth, but would have preferred more frequent sex. Unsurpris­ingly, the fathers were more dissatisfied with their sex lives than the mothers; 46% of men were unsatisfied compared to 36% of women.

Clearly, as the studies indicate, the demands of an infant affect couples’ sex lives. But, does the effect remain as children age? Children of all ages demand significant amounts of time and attention from their parents. When parents are asked why they engage in less frequent sexual activities they often point to the presence of children (Greenbladt 1983; Michael et al. 1994). The Call and colleagues (1995) study found that younger children (0–4 years old) had an independent negative effect on reported sex frequency, but older children (5–18 years old) had a positive effect on reported frequency. Of course, much of the negative effect of having a younger child may be driven by the inclusion of infants in the measure. It is unclear why having an older child might increase sexual frequency. The authors hypothesized that having teenagers in the house might make sex a more salient topic. One additional possibility might be that parents are making up for lost time by increasing their sex frequency as children require less attention and responsibility.

Employment and hours worked in paid labor present another possible inhibiting factor on couples’ sexuality. Dual earner households have become the norm rather than the exception (Blau and Kahn 2007; Juhn and Potter 2006; Raley et al. 2006), which suggests that women and men in a majority of households are choosing to divide their time between work and their private lives. This balancing act, combined with the time spent on housework and childcare, generally takes a toll on sexual frequency. A recent study based on a national sample of married couples found that balancing work and family demands and issues about sexual frequency were the top two issues that couples negotiated in marriage (Risch et al. 2003). Although some studies have documented a decline in sexual frequency caused by stress for both heterosexual and same-sex couples (Goh et al. 2004; Otis et al. 2006), it is not clear how much of the stress penalty is due to work-related stress. Studies that directly tested for the effects of work demands have usually found that for women and men, hours worked are not associated with couples’ sexual frequency (Call et al. 1995; Hyde et al. 1998). Indeed, a recent study by Gager and Yakibu (2009) provides strong evidence that dual earner couples are more than able to balance the demands of work and their private lives. Using the first wave of the NSFH and a sample of 6,887 couples, the authors tested whether hours worked at home and in the workplace predicted sexual frequency. Contra­dicting many of the authors’ initial hypotheses, the study revealed that both husbands and wives that spend more time on housework reported higher levels of sexual frequency—even after controlling for hours worked in paid labor. In addition, the couples who spent the most time on paid labor and housework were also more likely to report higher sex frequencies. What explains this unexpected finding? The authors argued that couples who work hard are more likely to play hard. These couples might represent a certain type of couple that the authors dubbed “go-getters”. High-performing couples may not only be more adept at integrating sex into their personal lives, they may also be more likely to place intimacy as a top priority for the sake of the relationship. Considering the time demands placed on dual earner couples, the common finding that number of hours worked does not negatively impact couples’ sex lives suggests that couples make time for sex—another indication of the primacy of sex in committed relationships.

However, in cultures where women are expected to do more housework, dual earner marriages may be more vulnerable to the demands of work and home affecting their sex lives. Cheung and colleagues (2008) analyzed a survey of 1,124 Hong Kong couples and found that women who worked full-time in the labor force reported lower sexual frequencies. The authors speculated that because Chinese women are still expected to be responsible for the majority of childrearing and housework, the demands of the second shift compete with the couple’s ability to maintain sexual frequencies that resembled those of women who did not work full time. Another study of mainland Chinese respondents, however, only found a weak connection between housework and sexual frequency (Ji and Norling 2004).

In sum, some life course events affect couples’ sex lives more than others. The transition to marriage and women and men’s decision to devote their time to paid labor does not appear to negatively affect couples’ sex lives. If anything, longer hours spent on household labor and paid work appear to increase sexual frequencies for some couples. However, the decision to introduce children into the relationship appears to place strong constraints on the sexual behaviors of parents. Pregnancy reduces the frequency of sexual behavior both during and immediately after the pregnancy. The finding that the presence of young children negatively affects couples’ sex frequencies, alongside the fact that postpartum sexual frequencies never return to their original pre-pregnancy levels, suggests that young parents’ sex lives are especially vulnerable.

4.3 The Effects of Sexual Dysfunction and Disease on Couples’ Sexual and Relationship Well-Being

We have assembled a long list of personal characteristics, gender norms and life cycle events that affect the sex lives of couples. Of the constraints on couples’ sexual lives that we discuss, the presence of a partner’s sexual dysfunction has the potential to have the most damaging impact on sexual frequency and satisfaction. For the most part, couples experience the aging process together, and life-course related challenges are expected. Sexual dysfunction, on the other hand, is a problem that may not be shared by both partners and might not be reversible. Furthermore, in a culture that equates sexual intercourse and sexual frequency with normality, a sexual dysfunction is disturbing and perhaps stigmatizing for both partners. Possible feelings of shame and embarrassment may help explain why many women and men do not choose to seek help for sexual problems (Laumann et al. 2009). This inability to ask for, and therefore receive, emotional and physical therapy will generally have a high negative impact on couples since studies amply demonstrate that sexual frequency and sexual satisfaction correlate with relationship satisfaction.

Sexual dysfunction has, however, definitional problems. There is quite a bit of inter- and intra-disciplinary disagreement about what should be considered a sexual dysfunction. There is also disagreement about the etiology of a given sexual issue. Medical, biological, sociological, and psychological experts disagree on whether something like the ability to be aroused or the proclivity to ejaculate prematurely have a cultural, interactional, or biological etiology. Behavioral scientists and social constructionists believe that women’s lesser sexual interest can easily be misdiagnosed as a sexual dysfunction when in reality a loss of sexual interest can be the result of an unsatisfying marriage, depression, or a generally difficult life (Tieffer 2006a).

Furthermore, as we analyze the studies on sexual dysfunction, we note the relatively weak link between biological processes and the incidence of sexual dysfunction among older adults. To be sure, some biological changes, such as menopause and andropause, affect sexual behavior as people age. But both national and international surveys of adults of all ages suggest that many sexual problems are also related to one’s psycho-social well-being. (e.g. Laumann et al. 1999, 2005, 2009; Lewis et al. 2004). In short, because context, gender, and psycho-social factors seem to affect the incidence of sexual dysfunctions, we cannot conclude that sexual dysfunctions are biologically inevitable.

Although sexual dysfunction is not the focus of this chapter, there are a few points worth mentioning that are particularly important for understanding couple’s sexual satisfaction. Using the American subset of the Global Study of Sexual Attitudes and Behaviors (GSSAB), a sample of 1,419 adults between the ages of 40 and 80 years, Laumann and colleagues (2009) reported that men’s most common sexual dysfunctions were premature ejaculation (26.2%) and erectile dysfunction (22.5%). Women’s most commonly reported problems were a lack of sexual interest (33.2%) and lubrication problems (21.5%). A study using the Brazilian subset of the survey found somewhat similar results for both women and men (Moreira et al. 2005). However, in another study using a sample of 1,550 women and 1,445 men, Laumann and colleagues (2008) found that the incidence of sexual dysfunction was more related to social-psychological factors rather than the aging process (although there was some evidence that health factors might be more important for women). These studies were limited to older Americans, so it is difficult to generalize to the entire population of adults and it is also important to note that these results are based on respondents’ subjective assessment of their sexual functioning. In any case, when trying to decipher the ups and downs of sexual frequency in committed couples, it is important to factor in the possibility of health-related causes and that health-related issues may operate differently for men and for women.

Several studies have documented a decline in sexual and relationship well-being for women and men with sexual dysfunctions. Moreira and colleagues (2005) found that sexual dysfunction was associated with depression and Laumann and colleagues’ (2008) study reported a correlation with lower partner satisfaction. Similarly, in their analysis of the NHSLS, Laumann and colleagues (1999) found that reports of sexual dysfunction were associated with lower sexual and relationship satisfaction for both women and men. Using the Boston Area Community Health Survey, which included a sample of 3,205 women between the ages of 30 and 79, Lutfey and colleagues (2009) found that of the 38.4% of women who reported some type of sexual problem, over a third reported being dissatisfied with their sex lives. Rosen and Althof (2008) reviewed 11 studies of men who experienced premature ejaculation, and found evidence that premature ejaculation was often associated with interpersonal difficulty between partners. However, the authors noted that the strength of the association between relationship conflict and premature ejaculation varied depending on what study they examined.

These studies suggest that sexual dysfunction undermines both women and men’s sexual and relationship satisfaction. However, it is important to note that while most of these studies tend to rely on large, representative datasets, we should be careful about inferring causality due to the reliance on cross-sectional study designs. While it makes sense that sexual dysfunction should lead to dissatisfaction with sex and the overall relationship, this may not be the entire story. Sexual intimacy is a heavily psychological process and, as some studies suggest, several sexual dysfunctions such as lack of desire and premature ejaculation may be affected by the quality of the relationship and sexual encounters (Laumann et al. 1999).

The partners of individuals with sexual dysfunctions also experience decreased sexual and relationship well-being. McCabe and Matic (2008) examined 40 heterosexual men with erectile dysfunctions (ED) and their female partners and found that sexual frequency began to decline when men first started to experience symptoms of ED. But it was not just the men who were affected by the decrease in sexual frequency; the onset of ED lowered the sexual satisfaction and relationship satisfaction for both partners. Cameron and Tomlin (2007) examined three groups of heterosexual women to investigate the effects of a male partner’s ED on the women’s well-being: 171 women had partners on medical treatment, 183 women had partners without medical treatment, and a control group of 151 women had partners without ED. The women who had partners with untreated ED reported the lowest levels of sexual satisfaction and lower sexual communication, while the women with partners in a treatment regime reported levels of sexual satisfaction and communication comparable to the control group. In addition, the women whose partners were not treated were the most likely to report lower levels of relationship satisfaction. Even more telling, a large British study based on a convenience sample of women and men who reported sexual problems in a clinic found that at least half of the women who complained of an inability to enjoy sex or achieve orgasm had a partner suffering from premature ejaculation (Riley and Riley 2005).

One sexual dysfunction in particular is associated with women’s transition into menopause—Hypoactive Sexual Desire Disorder (HSDD). The conceptualization of ‘inadequate desire’ as a clinical disorder is relatively recent and that alone makes it controversial to social scientists who believe that there is an over “medicalization” of sexuality (Tieffer 2006b). Critics of the HSDD diagnosis believe that medical professionals have created an arbitrary “normality” and that this definition, rather than a biologically-caused deficit, is promoted so that doctors can “cure” women and pharmaceutical products can make them “well” (Tiefer 2004). Feminist therapists prefer a more flexible definition of sexual health and are more predisposed to dealing with subjectively expressed sexual frustrations (as opposed to presumptions of HSDD if a woman is not interested in sex) through therapy that involves more interactive, cultural, or personal etiologies. At present, the HSDD “dysfunction” is defined as “the persistent or recurrent deficiency (or absence) of sexual fantasies/thoughts, and/or desire for or receptivity to sexual activity, which causes personal distress” (Basson et al. 2000, p.890). The appropriateness of this definition, as well as when low desire is appropriately labeled HSDD, continues to be debated in the literature. Although many medical professionals believe that HSDD is usually a direct result of reduced testosterone production, this definition suggests an important psycho-social component. Indeed, several studies have demonstrated that many of the symptoms and consequences of HSDD are relational. Dennerstein and colleagues (2006) sampled 2,467 women between the ages of 20 and 70 from France, Italy, Germany, and the United Kingdom and found that women who reported the onset of low sexual desire also reported a general dissatisfaction with their sexual and personal lives—a finding that has been reported elsewhere (Graziottin et al. 2009; Leiblum et al. 2006). Whatever the etiology of the problem, some women who were willing to try hormonal recalibration (testosterone supplements) did report increased sexual responsiveness (Braunstein et al. 2005; Buster et al. 2005). However, individual motivation for change may be an important variable in the effectiveness of any treatment for HSDD. A large cross-sectional study of American and European women between the ages of 20 and 70 found that older women were less emotionally distressed about the presence of HSDD than younger women (Hayes et al. 2007). This may be due to fewer partnered older women, or it may be that sex becomes less integral to psycho-social well-being among older women.

When one partner has a disease that affects their ability to perform intercourse, or for that matter, enjoy any form of sexuality, relationship well-being may be greatly reduced. Compared to the effects of sexual dysfunctions, there is less research examining how particular diseases may affect couples’ sex lives, probably due to a bias in the health journals to focus on individual rather than couples’ well-being. However, there are some relevant couples studies. Symms and colleagues (2008) surveyed 481 veterans who received an ostomy, a procedure—usually an opening in the intestinal area—used to treat rectal cancer or inflammatory bowel syndrome. The procedure often results in unpleasant side effects such as foul odors, gas, leakage, fatigue, and sleep disturbances—all effects that might harm a couple’s sex life and general sense of well-being. Prospective patients who filled out an open-ended questionnaire were aware of, and feared, these possible sexual side effects—with good reason. Post-operative results found that most veterans saw a steep decline in sexual frequency. However, perceived sexual satisfaction played a large role in whether the veterans were able to adjust to their lives post-procedure. Veterans who reported satisfying sex lives were more likely to have stronger personal relationships, meet new people, and have generally satisfying lives. The authors concluded that being able to have a sexual life was a primary part of these men’s identities and relationships, and that maintaining a sex life was a key to adjustment after the procedure.

Two other studies not only highlight how disease may negatively affect couples’ sex lives, but also the importance of coping strategies and partner understanding. A study of 50 women who survived cervical cancer and a control group of women who had not experienced cancer found that the quality of the post-cancer women’s relationships strongly predicted their reported sexual health (Donovan et al. 2007). Another study by McCabe and colleagues (1996) examined 37 men and 74 women diagnosed with multiple sclerosis (MS) in an effort to understand how the disease affected their sex lives and what qualities of the respondents’ relationships might influence their ability to cope with the disease. Many of the respondents with MS reported being dissatisfied with their sexual functioning and the decline in the frequency of sex in their lives. It was also common for respondents to report impaired sexual communication, and a more distant relationship with their partner. Respondents who reported that their partner expressed concern about sex or put pressure on the respondent to have sex were less likely to report satisfaction with their partner, and were less likely to engage in acts of sexual expression. However, respondents who reported healthy and supportive relationships with their partner were more likely to perceive that MS had actually had a positive impact on their sex life. Both studies demonstrate that having a loving partner can help patients with a chronic disease have a satisfying and fulfilling sex life.

No one would deny that sexual function and pleasure is severely challenged when serious and life threatening diseases are present. While the coping literature might be sparse, the evidence that exists can be inspiring. Many patients seek counseling and treatment and sexual medicine has begun to be more common and effective. If a loving partner is present, couples seem to be able to adjust to quite difficult situations and appear to be able to retain a sexual life together.

5 Non-Monogamy and Infidelity

Up to this point we have reviewed the literature on couples’ sexuality under the assumption that couples intend on maintaining long-term, monogamous relationships. While it is true that the vast majority of sexual behaviors take place in the context of dyadic, monogamous relationships, it is also true that not all partners are faithful, and not all couples choose to remain monogamous. Furthermore, recent decades have seen a rise in new forms of commitment that innovate relationship rules, rather than rely on past institutionalized expectations.

Still the core concept of marriage is that when partners commit to each other, they also commit to monogamy. Data from global sex surveys suggest that monogamy is the primary context for sexual relations in cultures across the world (Wellings et al. 2006). In America, attitudes regarding extramarital sex indicate that sex outside of a committed relationship is taboo. The NHSLS and the GSS have found that between 70 and 80% of Americans either completely disapprove of extramarital sex or believe that extramarital sex is always wrong (Laumann 1994; Smith 1994). Despite the popular perception that American attitudes about non-monogamy have become more permissive over the last several decades, the evidence suggests that both women and men became more disapproving of extramarital sex. During the 1990s, 90% of individuals in a national survey believed that extramarital sex was either always or almost always wrong (Thornton and Young-DeMarco 2001). This pattern of disapproval toward extramarital sex is also evident in most of Europe, but the U.S. is somewhat of an outlier in how much more conservative its stance is toward non-monogamous relationships relative to countries like England or France. Indeed, American condemnation of extramarital sex rivals historically conservative countries with large Catholic populations, such as Ireland and Poland (Widmer et al. 1998).But attitudes, as we know, are different than behavior, and American values do not accurately reflect American behaviors. Estimates suggest that extramarital sex is surprisingly more common than one might anticipate given what we know from the attitudes data. According to Laumann and colleagues’ (1994) analysis of the NHSLS, a full quarter of married men and 15% of married women reported engaging in extramarital sex at least once in their lifetime. Likewise, Wiederman’s (1997) analysis of the GSS found similar results with 23% of men and 12% of women reporting extramarital sex at least once over the course of their life. The 2009 AARP data suggest that the incidence of infidelity might be surprisingly high for older adults. Whereas the previously mentioned studies asked respondents about infidelity across the lifetime, the AARP asked respondents about infidelity during their current relationship. The data suggest that 21% of men and 11% of women had a sexual relationship with another partner during their current relationship (Fisher 2009). Of course, many of the respondents may have been partnered with their current partner for most of their life which would result in similar reports had they been asked to report on infidelity across their lifetime. Accordingly, when respondents are asked whether they engaged in infidelity during the previous year, the incidence of extramarital sex is much more rare; less than 4% of married respondents report engagement in extramarital sexuality in that time period (Laumann et al. 1994).

Age and gender have consistently been shown to be correlated with the lifetime incidence of infidelity. However, the relationship between age, gender, and infidelity is somewhat complex. Despite the attention given to gender differences in the incidence of infidelity, recent data suggest that for men and women under the ages of 40–45, the lifetime rates of extramarital sexuality are statistically indistinguishable (Atkins et al. 2001; Wiederman 1997). Atkins and colleagues (2001) note that more time must pass before we are able to conclude that, as they age, women and men continue to engage in similar rates of infidelity. On one hand, a cohort explanation would suggest that the younger cohorts will have equal likelihoods of engaging in extramarital sexuality as they age. For example, the economic emergence of women in the labor market may provide more opportunities for women to engage in extramarital sex by expanding their social and economic resources. On the other hand, we have already summarized evidence that suggests older women find it particularly difficult to find sexual partners relative to older men. If this cultural double-standard for older women and men persists, we might expect men to outpace women in rates of lifetime infidelity as the cohorts age.

Currently, we know that gender differences in rates of lifetime infidelity emerge when we examine respondents who represent the older cohorts at the time of data collection. The cohort of men aged 55–65 appears the most likely to have ever engaged in lifetime extramarital sexuality, relative to the younger and oldest cohorts of men. For women, the cohort aged 40–45 is more likely to have engaged in infidelity in their lifetime, relative to the younger and oldest cohorts (Atkins et al. 2001). However, some data indicate that the age interval for women most likely to have engaged in infidelity is somewhat wider (Wiederman 1997).

There is some evidence that other demographic characteristics, such as race and ethnicity, are associated with rates of infidelity. A handful of studies have found that African Americans and Hispanics are more likely to engage in extramarital sexuality relative to whites (Amato and Rogers 1997; Cochran et al. 2004; Treas and Giesen 2000; Wiederman 1997). However, few studies have systematically tested what mechanisms may explain the association between race/ethnicity and extramarital sex. The 2009 AARP study may give one clue: Hispanics who had extramarital sex were less likely to think it harmed their relationship. If correct, lower costs (i.e. a resilient relationship because of different norms or expectations about monogamy) may make extramarital sex more likely.

An assortment of additional individual-level characteristics has also been used to predict the likelihood that a partner engages in extramarital sex. Religiosity, measured as frequency of church attendance and respondent’s self-reported religiosity, is negatively associated with the incidence of extramarital sexuality. Specifically, the more a respondent appears to identify with a religion, the less likely that the respondent will report having sexual relations outside of the marriage (Amato and Rogers 1997; Atkins et al. 2001). Although some studies suggest that there are little or no differences in the rates of extramarital sex by religion or religious denomination (Forste and Tanfer 1996; Greeley 1994), a recent analysis of the GSS found that denominational differences exist among those respondents who most strongly identify with their religious group (Burdette et al. 2007). Other individual factors shown to increase the likelihood of reporting extramarital sex include reporting strong sexual interests, permissive attitudes toward infidelity, sexual opportunities such as available partners in the workplace, having a spouse that is weakly tied to one’s social network, neuroticism, pregnancy, a history of divorce, and a history of sexual abuse (Atkins et al. 2001; Laumann et al. 1994; Treas and Giesen 2000; Whisman et al. 2007; Whisman and Snyder 2007; Wiederman 1997).

The nature and type of the primary relationship also appears to affect the likelihood of non-monogamy. Cohabiters are significantly more likely to engage in extra-dyadic sex than married couples (Blumstein and Schwartz 1983; Laumann et al. 1994). Although we might expect that some of the higher risk of non-monogamy might be driven by cohabiters’ liberal views toward sexuality, cohabiters remain at higher risk even after controlling for their levels of permissiveness regarding extra-dyadic sexuality (Treas and Giesen 2000). Still, this finding does not rule out the explanation that married couples may have more traditional values to begin with, and maintaining traditional values may insulate the couple from having extramarital sex. It might also be the case that the legal nature of marriage (and the norms of marriage) raises the costs of infidelity for married couples relative to cohabiters.

Another obvious risk factor is the quality of the primary relationship. Partners in an unhappy marriage may be more likely to seek sexual gratification elsewhere. However, findings from research on the association between extramarital sexuality and relationship quality are inconsistent. Greeley (1991) found that relationship quality had an indirect effect on the likelihood of extramarital sex through respondent’s reported level of permissiveness toward extramarital sexuality. On the other hand, recent studies suggest that partners who are dissatisfied with their relationship are nearly four times as likely to commit infidelity compared to more satisfied couples (Atkins et al. 2001; Banfield and McCabe 2001). However, much of the literature examining the link between relationship well-being and infidelity suggests that the causality may operate in the other direction—infidelity itself predicts relationship well-being. Unfortunately, we are mostly restricted to cross-sectional research on this subject so it is difficult to discuss causal ordering. However, a handful of panel studies that in some cases followed respondents over the course of a decade, lend considerable credence to the argument that infidelity causes relationship dissatisfaction and dissolution (Amato and Previti 2003; Amato and Rogers 1997; Previti and Amato 2004).

Sex outside of the primary relationship appears especially likely among gay males. In their sample of gay men who were either cohabiting or in civil unions, Solomon and colleagues (2005) found that over half the gay men in both the civil union group and the cohabiting group reported having sex outside of the relationship during the duration of their relationship (compared to 15.2% of heterosexual partnered men). Similarly, half of the gay men in civil unions and one-third of the gay cohabiting men reported having an agreement that sex outside of the relationships was not permissible (compared to about three-fourths of heterosexual partnered men). The finding that gay men have a high risk of engaging in extra-relationship sexuality is, of course, not a new finding (Blumstein and Schwartz 1983; Bryant and Demian 1994; Wagner et al. 2000).

Interestingly, infidelity does not appear as strongly associated with relationship dissatisfaction for gay men relative to heterosexual couples. Although based on convenience samples, there is evidence that gay men are much more likely to successfully negotiate extra-dyadic sex compared to lesbians and heterosexual couples (Blumstein and Schwartz, 1983; Bryant and Demian 1994; Solomon et al., 2005). LaSala (2004) found that gay couples’ commitment levels were not undermined when the couples maintained enforceable agreements regarding non-monogamy that placed the primacy of the couple before the secondary, extra-dyadic relationships. Furthermore, even in the event that a partner reneged on the agreement, the couples were able to successfully mend the relationship if there was an open discussion about the indiscretion. These findings replicate earlier studies that found that gay men in open relationships resembled the gay men in sexually exclusive relationships in terms of levels of commitment and expressions of affection (Blasband and Peplau 1985).

Some researchers believe that this fact (that gay male couples are more non-monogamous than other couples) shows a biological proclivity of men that is demonstrated when men are not bound by the more monogamous values of a female partner. While unconstrained male sex drive may play a role, a large group of researchers believe that cultural explanations still have high explanatory value (Brickell 2006; Gagnon and Simon 2005; Seidman 2003). Most scholars report that gay male culture is more permissive toward extra-dyadic sexuality relative to heterosexual and lesbian culture (Blumstein and Schwartz 1983; Bryant and Demian 1994). Blumstein and Schwartz (1983) found that many gay men in non-monogamous relationships felt that sex outside of the relationship was acceptable as long as the sex was of a casual, impersonal nature. Gay men in the study managed to maintain stable relationships with their primary partners because casual sex partners did not compete with the primary relationship; impersonal sexual encounters rarely developed an emotionally-charged, romantic quality. However, the authors found that despite the gay men’s permissive attitudes and behaviors, non-monogamy did take its toll on sexual satisfaction within the primary relationship. Some men equated casual sex with adventure and novelty and thus found their sex lives with their primary partner less exciting. A more extreme cost, a higher relationship dissolution rate, occurred if men had an affair, as opposed to casual sexual encounters.

What explains the observed variation in the acceptance of and participation in extra-dyadic sexuality among gay men? Adam (2006) interviewed 70 gay male couples in Toronto and found both demographic and cultural explanations for gay men’s perspectives on non-monogamy. The author found that younger men—men who were more likely to be new to the gay lifestyle—were more likely to follow scripts of monogamy. Adam (2006) speculated that younger men’s formative years occurred during a period where homosexuality is more accepted and issues like the gay marriage debate are prominent, whereas older gay men’s development occurred during the gay liberation movement—a movement that occurred contemporaneously with public debates that questioned the role of monogamy. Adam (2006) also found that gay men who came of age in the absence of a local, indigenous gay community were more likely to practice monogamy in their relationship, a finding that lends credence to the gay sub-culture explanations from earlier research (Blumstein and Schwartz 1983; Bryant and Demian 1994)

Consensual non-monogamy is not just a phenomenon among gay male couples. Certain “experimental couples” including heterosexual, lesbian, married, and cohabiting couples participate in non-monogamous relationships. Like their gay male counterparts, the rules and expectations regarding what is permissible and what is good for the relationship are negotiated by the primary couples (Blumstein and Schwartz 1983; Parkinson 1991; Schwartz and Rutter 1998). Heterosexual swingers and heterosexuals who adopt polyamory (committed relationships between more than two consenting individuals) believe that non-monogamy can be consensual and does not undermine the commitment or stability of the primary relationship. In studies of swingers, findings suggest that there are few differences in dissolution rates when comparing sexually open couples and sexually exclusive couples. According to Rubin and Adams’s (1986) follow-up study of 82 couples, married couples with exclusive sexual relationships were statistically indistinguishable from married couples with open relationships in regard to marital stability.

It is also true, that many couples start out monogamous and the relationship evolves into polyamory, or the couples begin swinging, often introduced by one partner as a form of sexual adventure and experimentation (Blumstein and Schwartz 1983; Jenks 1998). An interest in unconventional sexuality can start during college years where formal on-campus groups help organize people of common sexual beliefs and proclivities and, in recent years, sexual networks form easily on the Internet. Early research on swingers indicated that they tended to be white, middle- to upper-middle class, and more highly educated (see Jenks 1998). Later studies have unfortunately been scarce. We do not know why many gay men and some other kinds of couples can embrace non-monogamy and keep their relationship happy and intact, while most other couples will not consider anything but sexual exclusivity and are likely to unravel if either partner has an outside sexual relationship (Schwartz and Young 2009).

6 Sexuality Among Dating Couples and Casually Committed Couples

As we mentioned at the beginning of this chapter, commitment itself has become harder to measure. We believe that there is now an intermediate kind of relationship- one that we call “casual commitment”. In our view, these are couples who are not married, do not cohabit, yet can have long-term sexual relationships that establish them as a couple in other people’s eyes, as well as in their own. Long-term dating and other forms of causal commitment have become a salient part of many adults’ lives. Trends in delayed marriage and the extension of adult years spent in education and career development suggest that the early years of adult life have become more emotionally complicated. In addition, high divorce rates have created a large middle-aged group of single adults who do not want to be alone, but are ambivalent about living with someone again or opposed to getting remarried. Many adult singles thus reenter the dating market and create continuing relationships that do not entail cohabitation.

Thus, for both older and younger populations, extended dating and ambiguous commitment are new facts of life. Data from the 1980s to 1990s suggest that the majority of adults are sexually active before they marry. Two studies of pre-married men found that nearly 90% of men were sexually active before marriage. When asked about the number of sexual partners during the previous year, most men reported having one partner, but depending on the study somewhere around 15–18% had four or more partners (Billy et al. 1993; Laumann et al. 1994). Similar results were found for women, although women were somewhat less likely to report larger numbers of total premarital partners (Laumann et al. 1994; Tanfer and Cubbins 1992). Recently, using the NSFG, Lindberg and Singh (2008) found that of the 36% of women who reported being single, 90% were sexually experienced. Furthermore, 70% of the sexually experienced single women reported being currently sexually active, and singles were more likely than cohabiters and married couples to have two or more partners within the last 12 months. Finally, data from four cycles of the NSFG found that 75% of adults had premarital intercourse by age 20; this percentage increased to 81% by age 44 (Finer 2007). Thus, it is clear that women and men are engaging in sexual activity before long-term commitments, but are not necessarily totally uncommitted. Although we cannot tease out those who are in a relationship from those who are just having sex for purely recreational purposes, it is likely that the majority of these adults are in some kind of relationship.

Dating is probably the most common method that adults use to engage in sexual behavior outside of cohabitation and marriage. As we discussed before, perhaps to the surprise of the casual observer, non-elderly, single adults are having less sex than their cohabiting and married counterparts (Blumstein and Schwartz 1983; Laumann et al. 1994), and non-elderly, single adults are also less satisfied with their sex lives (Blumstein and Schwartz 1983; Laumann et al. 1994). Sprecher’s (2002) study that followed 101 intact premarital, dating couples for up to 4 years is one of the few studies that examined the role of sexual satisfaction in the maintenance and health of ongoing dating relationships. Like cohabiting and married couples, sexual satisfaction was associated with relationship satisfaction, love, and commitment. As time passed, couples’ sexual satisfaction increased as feelings of love and commitment levels increased. Although we might expect that the association between sexual satisfaction and other indicators of relationship quality might decrease over time for dating couples, no such association was found. In short, it appears that a satisfying sex life is just as important for dating couples as it is for more committed couples. It should be noted, however, that the study—like most studies of dating couples—was limited to a sample of undergraduate students who may resemble adolescents more than they resemble adults.

While the Sprecher (2002) study demonstrates the importance of sex to dating couples, it does not explain why single, non-elderly adults are less likely to report satisfying sex lives. It may be that the dating relationship is inherently unstable and that this instability infects all parts of the couple’s life together. We have already established that good communication and shared goals are important for couples’ sex lives, and both may be absent or not well established in the early stages during dating. Following this logic, a handful of studies—again based on undergraduate dating experiences—suggest that negotiating sexual behavior may be somewhat perilous for dating couples. Two studies (Impett et al. 2008; Impett and Peplau 2003) found that some daters, both women and men, who are anxiously attached to their partner (i.e. fear that their attachment figure is unreliable or unsupportive during times of need) are more likely to engage in unwanted sex. Daters who have avoidant attachment styles (i.e. general distrust of partners and preferring emotional distance) are also likely to engage in unwanted sex because they wish to avoid the conflict that may arise if they refuse sex. Similarly, regardless of attachment style, some daters who may not want to have sex may do so anyway to fulfill a partner’s needs, promote intimacy, and avoid relationship tension (O’Sullivan and Allgeier 1998). While these findings are likely to also apply to more stable forms of committed relationships like marriage, they may be most salient for dating couples who are in the early stages of self-disclosure.

Dating relationships become even more complicated when adults experiment with other types of sexual choices that blur the boundaries of traditional commitment. One such type of relationship that has received a lot of attention in the media and popular culture is the “friends-with-benefits” relationship. In some ways friends make ideal sexual partners. Friendships are based on trust and mutual interdependence, and the qualities that respondents associate with friendships and romantic relationships are more similar than they are different (Sprecher and Reagan 2002). Bisson and Levine (2009) interviewed 125 undergraduates to inquire about their experience with friends-with-benefits arrangements; 60% of the respondents had maintained a friends-with-benefits relationship at some point in their life and 36% were currently engaged in such a relationship. Interestingly, acquiring intimacy without the burden of commitment was the number one listed advantage of experimenting with the friends-with-benefits arrangement. The most frequently cited drawback to the friends-with-benefits arrangement was a fear that one partner might develop unreciprocated feelings for the other. On the one hand, respondents appeared to engage in these relationships to avoid heavy commitment, while on the other hand respondents chose to be intimate with a friend—a relationship that does require a certain level of commitment—rather than engage in casual sex with someone they are less attached to.

Recent research by England and Thomas (2007) sheds additional light on the correlates and consequences of the “hook-up” culture that has been documented on many college campuses. The authors conducted an online survey with 615 heterosexual, undergraduate respondents and supplemented the data with 270 additional in-depth interviews. The authors found that only 20% of respondents had never experienced a hook-up, while over a third had hooked up more than ten times. When asked about the motivation to hook-up, alcohol was frequently involved; prior to the hook-up, men averaged seven drinks and women averaged four drinks. Interviews with the respondents suggested that a “friends-with-benefits” relationship might emerge after several subsequent hook-ups. The authors also found evidence of gender inequality in the hook-up scene that rivaled the sexual double-standard that often accompanied old-fashioned dating. Women who hooked up were much less likely to achieve orgasm compared to men, suggesting that the hook-up is centered more on men’s rather than women’s pleasure. Specifically, of the women and men who engaged in oral sex or intercourse during a hook-up, only 32% of women achieved orgasm compared to 84–90% for men. England and Thomas’s (2007) findings imply that, at least on college campuses, the old-fashioned date may be on the decline, and hook-ups may be becoming an attractive way to build intimate relationships. However, insofar as hook-ups disadvantage women in their experience of sexual pleasure, we caution any argument that the hook-up is the natural consequence of the sexual revolution and its message of gender equity.

Very little is known about the longer-term dating relationships of older adults. We have mentioned that a large proportion of older adults maintain healthy, regular, and satisfying sex lives. Yet it is unclear what the actual sexual lifestyle is for older adults that most surveys continue to classify as “single”. The AARP study is one of the few studies that does ask single adults if they are in a committed, dating relationship. The data suggest that older, dating adults are having more sex than their cohabiting and married counterparts, and that they are enjoying sex more than what surveys would suggest of their younger, single counterparts (Fisher 2009). This finding might indicate that some older couples are unhappy or sexually bored in stable relationships, while dating, single older adults are in relationships that are rewarding (or they would have been discontinued). The single relationships are probably of shorter duration and that has an independent effect on sexual frequency and intensity. It is also possible that a certain level of space, separation, and autonomy eroticizes, or in other ways, supports a sexual relationship. Karlsson and Borell (2002) surveyed 116 Swedish adults between the ages of 60 and 90 who were in committed relationships but did not live or intend on living with their partner. Most of the respondents favored not sharing living quarters because it allowed them a high degree of autonomy. This independence was particularly important for the women; many women feared that sharing a residence would lead to a gendered, unequal division of household labor. The women wanted intimacy, but not the highly gendered responsibilities (e.g. cooking, cleaning, and caretaking) that they associated with traditional living arrangements.

Older adults are not the only people who are experimenting with non-residential commitment. The increasingly popular but still rare “living-apart-together” (LAT) arrangement—where partners do not share the same residence—is just one more example of the reduction of social norms surrounding committed relationships. In Sweden, as of 2001, it is estimated that 14% of individuals who were not married or cohabiting reported being in a LAT relationship, while 60,000–70,000 Norwegian individuals reported such a relationship (Levin 2004). Figures from the Canadian General Social Survey suggest that 8% of the Canadian population is engaged in a LAT relationship (Milan and Peters 2003). The study found considerable age variation in the incidence of LATs: 19% were in their 30s, 14% were in their 40s, and 11% were 50 or over. Over half of those in LATs desired a common law marriage, suggesting a high degree of commitment. However, partners in LATs were less likely to be as future-oriented as their married counterparts. They were also less likely to agree that the presence of a child would improve their lives. Qualitative interviews with couples in LAT relationships found that many couples desired to share a residence, but were unable to make the transition because career and/or family obligations prevented them from doing so (Levin 2004). Thus, much of the increase in LAT and other experimental relationships may be driven by constraints that are external to the relationship. But external constraints are not the only motivating factor behind the LAT arrangement. Some adults reported a hesitance about moving in together after experiencing problems in prior married or cohabiting relationships (Levin 2004). In sum, the new LAT arrangements can be attributed to practical considerations at different stages of the life cycle, work and family constraints, and changing norms surrounding close relationships. Unlike previous generations, having sex with a steady partner even in a committed relationship does not always require coresidential status.

What is the impact of these kinds of separate living conditions? What happens to the sexual relationships of committed partners or spouses who are unable to live in the same residence because of work and educational obligations? These sustained long-distance, “commuter marriages” can exert strain on a couple’s sex life which could reduce their sexual and relationship well-being. One study that compared “commuter marriages” to dual earners who shared a residence found that while the commuter couples were more likely to be satisfied with their work life and personal time, the quality of family and personal relationships (part of which included intimacy) was lower for the couples who did not live together (Bunker et al. 1992). However, other studies found that long-distance couples were indistinguishable from non-commuter couples on a number of relationship characteristics including intimacy (Guldner and Swensen 1995). A study of long-distance, student couples found that it was possible to maintain successful long-distance relation­ships as long as the relationship was firmly established before the separation; in addition, success relied upon trust, regular communication, and quality shared time (Magnuson and Norem 1999).

Clearly, it is becoming increasingly common for sex and intimacy to occur outside of the traditional context of marriage or even cohabitation. This is not all that surprising when one considers the dramatic shifts in cultural attitudes toward premarital sex, the trend of delayed marriage, women’s increased ability to create lifestyles independent of men, and an economy that requires adults to compromise ideal working/living situations and further extend the years they spend acquiring education. A higher divorce rate plus longer lives, coupled with a continued desire for sexual and emotional companionship, requires relationship innovation among older adults. However, we know very little about the full range of these arrangements. Most of the research concerning sexuality in dating relationships uses adolescents as the unit of analysis. This is probably because dating has traditionally been seen as a stage of adolescence that has been studied, more often than not, to analyze potential negative outcomes such as early marriage, teen pregnancy, and sexually transmitted infections (STIs). The few studies on adult dating that do exist usually rely on undergraduates as subjects, which limits our ability to generalize to the entire adult population. With an extended lifespan and the increased ability to find new partners at any point of the life cycle (through cultural permission and new institutional supports such as online dating), the phenomenon of sex and dating in the later adult years will have a significant impact on individuals’ physical and mental health. We hope there will be more scholarly attention to this new development in the life course.

7 Conclusion

Sexuality within committed relationships is an important topic for demographers for several reasons. First, as we have established, the majority of sexual behavior takes place within the context of a committed, dyadic relationship, and the satisfaction, health, and durability of a couple’s relationship is intertwined with the functionality of their sex lives. Second, most children are born in committed relationships and patterns of fertility are closely related to how couples approach their sex lives. Finally, we might emphasize that the spread of STIs, including HIV, is not simply a result of people who have uncommitted sexual encounters. STIs are often brought into a committed relationship from a sexual connection with a third party. Demographers studying sexuality because of their interested in morbidity and mortality, need to remain alert to the possibilities of dishonesty about sexual fidelity even in highly committed couples.

There is a good deal of research to bring to bear on these and other issues, but we also have some major methodological and disciplinary limitations that have constrained scholars of sexuality for several decades. Specifically, we need more longitudinal research. A reliance on cross-sectional data has limited our ability to generalize about key causal processes that connect sexuality, personal emotional and physical health, and relationship well-being. Sexuality researchers have intermittently recognized this weakness and there are a handful of well-designed, longitudinal studies that follow couples over time. However, the management and implementation of such study designs are time-consuming, costly, and funding sexual topics is usually difficult, so findings from longitudinal studies are usually based on smaller samples across a small number of time points.

Another problem in the field is a reliance on samples of married, heterosexual couples. This is understandable: the vast majority of Americans marry, and most children are born to parents who are married or will marry. However, over the last several decades we have been witness to the advent of many other family arrangements, and these arrangements are likely to become increasingly numerous. We do not know enough about the sex lives of cohabiting couples, and our data on same-sex couples is extremely limited. We need the inclusion of detailed and well-validated measures of sexual orientation on nationally-representative surveys that include questions about commitment and sexuality. Finally, a weakness that is surely obvious to the readers of this volume is a stunningly, almost non-existent, body of comparative literature examining sexuality within couples. Of course, this is not just a critique that applies to the study of sexuality in general, but it should be noted that the large scale international studies we do have are more focused on factors tied to the health and the spread of STIs than how couples manage their sex lives. The few studies that we have touched upon in this review clearly demonstrate the importance of contextual factors at the regional and cultural level. A better understanding of commonalties and differences across countries might allow researchers to construct better public policy on fertility, morbidity, and health.

Despite these limitations, scholars of sexuality have made progress understanding the complex dynamics that govern couples’ sexuality. We know that, almost universally, sexual satisfaction is important for personal health and relationship well-being. We also know that couples’ sexual lives are deeply affected by contextual factors that include interpersonal relationship qualities and cultural attitudes about sexuality. Furthermore, we know that couples’ sexuality is also changed by their transitions through the life course. All transitions do not affect couples the same way—for example, the labor force participation of women seems to matter in some countries, whereas in other areas it has little or no impact. Likewise, in some regions relationship duration takes a toll on sexual frequency, but in others, sexual frequency is unaffected by duration. The inconsistency of findings across cultures and countries should motivate us to find out more about the conditions and life events that affect couples’ sexual health and relationship durability and happiness.