McBride and Fortenberry's “Heterosexual Anal Sexuality and Anal Sex Behaviors: A Review” (2010)
[M]ost research on anal intercourse addresses men who have sex with men (MSM), with relatively little attention given to anal intercourse and other anal sexual behaviors between heterosexual partners (Halperin, 1999). Heterosexual penile–anal intercourse has been treated as analogous to coitus in most published research. Research is quite rare that specifically differentiates the anus as a sexual organ or addresses anal sexual function or dysfunction as legitimate topics. As a result, we do not know the extent to which anal intercourse differs qualitatively from coitus.
Depictions of heterosexual anal sex can be found in art and artifacts dating to antiquity (Reinisch, Ziemba-Davis, & Sanders, 1990). Peruvian Moche stirrup-spout pots, erotic ceramic vases, from 300 AD may be some of the earliest and most prolific examples of such representations (see Figure 1). A survey of Moche pots found that 31% depicted heterosexual anal intercourse, significantly more than any other sexual act (Tannahill, 1992). Chinese and Japanese shunga, woodblock prints and painted handscrolls, produced between the 16th and 19th centuries, depict a vast array of sexual practices, including heterosexual anal sex. Erotic French lithography and photography from the late 19th and early 20th centuries include both images of penile–anal intercourse, as well as digital–anal penetration. Erotica from the same period has described heterosexual anal sex acts.
The sexual use of the term sodomy as a synonym for anal intercourse among homosexual men is attributed to the Byzantine emperor Justinian I (538 AD). During the Medieval Inquisition (1184), hereticism was increasingly associated with fornication and sodomy, thus linking the behaviors to witchcraft and satanism.
Laws banning acts of sodomy can be traced to documents written between 500 and 600 AD. Historians have traced earlier bans to 149 BC; however, definitive written documentation no longer exists. Historically, anti-sodomy laws have been used to punish same-sex sexual behaviors, particularly anal sex among men.
A search of newspaper articles and newswire press releases (also conducted by us) for the past two decades indicated that early coverage (1986–1996) of anal sex focused on risk for HIV and AIDS, whereas articles published within the past five years focused on laws, sexual liberties, and sexual expressions.
Based on an extensive review of the research, Voeller (1991) estimated that at least 10% of sexually active American women engage in receptive anal intercourse with some regularity. Halperin (1999) pointed out that even if this estimate is inflated twofold, anal intercourse occurs among more women annually than among MSM—four million versus one million, respectively.
The National Health and Social Life Survey (NHSLS) has been a frequently cited source of prevalence data for anal intercourse (Laumann et al., 1994). The NHSLS found a past 12 months prevalence rate of 10% among men and 9% among women, with 2.3% and 1.2%, respectively, reporting heterosexual anal intercourse during their most recent sexual event (Laumann et al., 1994).
32% of participants reported at least one instance of anal intercourse within the preceding six months (Gross et al., 2000). One percent of the sample (n = 17) reported anal intercourse, but no vaginal intercourse, within the past six months.
In Project RESPECT, the proportion of participants reporting anal intercourse in the previous three months was two times higher in RESPECT II (1999–2000) than in Project RESPECT (1993–1995), increasing from 9% to 22% among women and 9% to 21% among men (Satterwhite et al., 2007). These changes were seen regardless of gender or study site and were consistent across racial and ethnic groups. Further, the increase in reports of anal intercourse also occurred across age groups, suggesting an historical increase in reporting rather than a cohort effect.
Both men and women with a history of same-sex partners are more likely to report anal intercourse (Foxman, Aral, & Holmes, 1998a, 1998b). Gorbach et al. (2008) found that the use of sex toys was associated with anal intercourse in men and women. Studies exploring prevalence by gender report that women participate in anal intercourse at roughly equal or slighter higher rates than men (Baldwin & Baldwin, 2000; Erickson et al., 1995; Lewis & Watters, 1991; Reinisch & Hill, 1995). Ethnic and racial group differences in rates of anal intercourse are inconsistent, although Hispanic men and White women have generally been found to report the highest rates (Erickson et al., 1995; Gross et al., 2000; Laumann et al., 1994).
Most of the data about heterosexual anal intercourse is based on research conducted in samples with behavioral and demographic characteristics (e.g., injection drug use or offering sex in exchange for money) that place them at relatively high risk for HIV and STI transmission. The extent to which the association of heterosexual anal sex among these populations is causal (e.g., through substance-related disinhibition) or distal (e.g., propensity for sensation-seeking) is unknown. Moreover, little is known about the characteristics of lower risk populations, although observed rates of anal intercourse have been found to be higher within the contexts of serious or long-term relationships, cohabitation, and marriage when compared to casual partnerships (Erickson et al., 1995; Gurman & Borzekowski, 2004; Houston, Fang, Husman, & Peralta, 2007; Lewis & Watters, 1991).
A study that investigated the underreporting of sensitive behaviors, with a particular interest in abortion, found that participants (n = 63) were more willing to admit to having an abortion than to engaging in anal intercourse (Smith, Adler, & Tschann, 1999). Although the small sample size limits the ability to make inferences, the findings suggest that anal sexual behaviors are underreported.
Voeller (1991) commented on the Bolling (1977) study, stating patients initially denied engaging in anal intercourse and only acknowledged and discussed this aspect of their sexuality at the second or third interview.
[H]igher frequencies of anal intercourse were found among participants with main partners (about once per week) compared to those with casual partners (about once per month; Houston et al., 2007).
A study of 2,357 heterosexuals found that for anal intercourse in the past three months, 27.3% of participants consistently used condoms, whereas 63% never used condoms. Consistent condom use for anal intercourse was associated with having consistent condom use for vaginal intercourse, two or more partners, and anal intercourse with a casual or new partner (Tian et al., 2008).
Methodological problems make estimating actual condom use for heterosexual anal intercourse problematic because the majority of studies investigating condom use fail to distinguish between vaginal and anal sex. Further, sample sizes have often not been large enough to conduct statistical analyses that specifically focus on anal intercourse in heterosexual men and women.
Few studies have explored the reasons for lower condom use during anal versus vaginal intercourse. McBride and Janssen (2007) found that relationship status and number of sexual partners significantly predicted condom use among men, whereas only relationship status was found to be a significant predictor for women. Other studies have identified themes associated with the perceived risks of STI and HIV infection and pregnancy as being associated with condom use.
McBride, Sanders, and Hill (2009) investigated the prevalence of non-intercourse anal sex behaviors among a sample of men (n = 1,299) and women (n = 1,919) with anal intercourse experience and found that 51% of men and 43% of women had participated in at least one act of oral–anal sex, manual–anal sex, or anal sex toy use.
Three general types of increased risk have been suggested to be associated with anal intercourse: trauma to the anus and rectum associated with penile insertion and thrusting; inflammatory responses to cleansers, lubricants, or semen; and increased presence of types of cells directly infected by specific organisms (Naftalin, 1992; Tabet et al., 1999).
Unprotected anal intercourse is a key risk factor associated with heterosexual HIV transmission (European Study Group, 1992; Skurnick et al., 1998). The per-act risk of HIV transmission is estimated to be five times higher for receptive anal intercourse and 1.3 times higher for insertive anal intercourse, compared to vaginal sex (Varghese, Maher, Peterman, Branson, & Steketee, 2002).
Receptive anal intercourse is associated with increased risk of anal cancer among women in some studies (Daling et al., 2004; Hernandez et al., 2005; Moscicki et al., 1999; Sharma, Ranjan, & Mehta, 2004) but not all (Tseng, Morgenstern, Mack, & Peters, 2003). HPV-related cancers likely occur in the absence of reported anal intercourse because of underreporting or because of virus contained in vaginal discharge, or associated with non-intercourse anal sexual behaviors (Moscicki et al., 2003; Winer et al., 2003).
[N]o studies document the frequency or extent of local trauma associated with anal sex, and none have attempted to demonstrate reduction in local trauma associated with lubricant use. Abrasions to the penile skin may also occur during anal intercourse, increasing the possibility of HPV infection should the partner be infected. Although penile cancers are associated with HPV, we find no data that directly links anal intercourse to increased risk of HPV-associated penile cancer.
Longitudinal findings suggest that anal HPV infections in healthy women resolve quickly, although anal intercourse is among the non-viral factors found to delay clearance (Shvetsov et al., 2009).
Many studies have reported higher STI rates among heterosexuals with anal intercourse experience when compared to those without (Auslander et al., 2009; Baldwin & Baldwin, 2000; Bogart et al., 2005; Gross et al., 2000; Kim et al., 2003) ... Screening studies where both genital and anal or rectal specimens are obtained show that anal intercourse is an STI risk factor, but only for men (Nelson et al., 2007).
receptive anal intercourse before vaginal intercourse is independently associated with the acquisition of bacterial vaginosis (Cherpes, Hillier, Meyn, Busch, & Krohn, 2008). The mechanisms by which anal intercourse influences vaginal microflora are unclear because overlap in the two microbial communities is substantial (Van der Pol et al., 2009).
[R]esearchers found that among a sample of 589 college students, 19% of respondents did not consider anal intercourse to be sex (Sanders & Reinisch, 1999).
The coupling of prevalent heterosexual anal sex images in pornography and erotica and the rise in behavioral pre- valence has led to the suggestion that pornography may be influencing the actual incidence of anal sex. We could not find any evidence to support or refute the possibility.
Because much of the research, to date, has been conducted within an infection risk paradigm, little consideration has been given not only to anal sexual pleasure, but also to anal sexuality.
Quotations from individuals who were interviewed for the articles or who posted comments on the blog were analyzed for themes, and those found tobe recurrent were organized into conceptual categories. Six broad categories were identified, including intimacy–trust–gifting, novelty–variety, control–domination, taboo–forbidden–erotic, pain–pleasure, and relationship status–context.
Although not generalizable, the quotations suggest that for a certain number of heterosexuals, anal intercourse is pleasurable, exciting, and perhaps considered more intimate than vaginal sex.
Few studies have devoted attention to sexual pleasure as a motivating factor for anal sex. A small number of studies have briefly commented on sexual pleasure as one aspect of anal sex; however, none has clearly related experiences of pleasure to behavioral motivation. A study that investigated the associations between the pleasurability of various sexual activities and behavioral experiences with the activities found gender main effects for anal intercourse, with heterosexual men rating anal intercourse significantly more pleasurable than women (Pinkerton, Cecil, Bogart, & Abramson, 2003). Among women, higher pleasure ratings were correlated with increased behavioral frequency for all behaviors, except anal intercourse. An earlier study of gender differences in college students’ attitudes toward sexual behaviors found that men had significantly more positive attitudes toward anal intercourse than women did (Wilson & Medora, 1990). A study that explored young women’s motivations for engaging in anal intercourse found that 58% of the women in their sample who had engaged in anal intercourse reported doing so at the request of their male partner (Flannery et al., 2003). These data do not provide information on whether this result differs markedly from gender differences in coital initiation or whether the 58% of women found anal sex to be unpleasurable or unerotic. However, 45% of the overall sample of women said that they had engaged in anal receptive penetration with a finger or sex toy (e.g., butt-plug, dildo, or vibrator), suggesting that pleasure may be a behavioral motivation for some women who engage in anal activities.
[A] study investigating intimate partner violence and HIV risk among methadone-maintained women (n = 416) in New York City found that intimate partner violence (sexual or physical) was associated with having unprotected anal intercourse (El-Bassel, Gilbert, Wu, Go, & Hill, 2005).
Dominant sexual scripts are phallocentric and value “insertive” sexual behavior over “receptive” sexual acts. Pervasive gendered scripts coupled with the stigma associated with anal sex make receptive anal intercourse one of the least desirable sexual behaviors in Western culture. As a result, there is a cultural assumption that women should view anal sex as undesirable or unerotic and that participation in the behavior can only legitimately result from some level of coercion or acquiescence. This perspective does not allow for wanted anal sex, which marginalizes the sexuality of women who find anal sex pleasurable or erotic. By disallowing the possibility of pleasure in anal sex, cultural discourses are reinforced.
Phallocentric discourses and the stigma associated with anal sex have influenced the study of heterosexual anal sex by sexual scientists. Research has assumed that anal sex behaviors in women are strictly receptive. Among men, the measurement of anal sex behaviors has been limited to penile–anal insertive or to penile–anal receptive intercourse, which implies a male partner. Very few efforts have been made to understand receptive anal sex behaviors in heterosexual men with female partners, including anal masturbation.
Anal sex is clearly part of the contemporary heterosexual sexual repertoire and has been for centuries. However, to consider anal sex predominantly as a marginal or atypical heterosexual behavior contributes to its continued stigmatization. That stigma never contributes to sexual health is among the many harsh lessons of the worldwide epidemics of HIV and AIDS.