The English language has a diverse vocabulary for describing human sexuality. Scientists and physicians use relatively sterile and precise terms to describe sexual anatomy and behaviors, and most of these terms have slang, euphemistic and child-appropriate equivalents. Despite this linguistic richness, the terms commonly used by scientists, the medical community and educators—“virginity,”“abstinence” and “sex”—lack the precision and shared meaning that we rely upon for unambiguous communication. Professionals themselves use these terms inconsistently. For example, in some contexts, abstinence encompasses any and all sexual activity with oneself or others, but in others, it refers to a more limited scope of behaviors, such as those that carry a risk of STD or may result in conception. Perhaps most infamously, President Bill Clinton played on the ambiguity concerning what behaviors constitute sex by emphatically stating at a White House press conference in January 1998 that he “did not have sexual relations” with a White House intern. Some considered this statement misleading when it later became known that oral-genital contact had occurred, yet many Americans shared the interpretation that President Clinton relied on.1,2 Like President Clinton, adolescents and young adults often interpret these words with a degree of latitude, depending on whether they want to maintain an image of being sexually experienced or inexperienced.3

Merriam-Webster's definition of sex—“sexually motivated phenomena or behavior”4—encompasses a wide range of behaviors. Nevertheless, although the general consensus appears to be that vaginal intercourse constitutes sex,2 classification of other forms of sexual expression has been inconsistent.5 For example, in a 1991 study of college students, the proportion reporting that they would say they had “had sex” was greater than 99% if the most intimate behavior they had engaged in was penile-vaginal intercourse, compared with 81% if it was penile-anal intercourse, 40% if it was oral-genital contact and 15% if it was hand-genital contact.2 A replication study using data collected in 1999 and 2001 found identical results.1 Similarly, responding to a series of brief hypothetical vignettes, 93% of a sample of college students surveyed in 1998 indicated that vaginal and anal intercourse constitute sex, but only 44% gave the same response for oral-genital contact.6

The absence of shared meaning concerning oral-genital contact poses challenges for attempts to elicit accurate sexual history information in research or clinical contexts,7 as well as for conveying information in educational settings. Furthermore, although partially anecdotal, some evidence suggests that since the mid-1990s, oral-genital contact has become increasingly prevalent among youth as a more acceptable and less risky alternative to penile-vaginal intercourse.7–8 If and as a transition in attitudes occurs, views on whether oral-genital contact constitutes having had sex may shift as well. Regardless of the direction, a shift toward greater agreement concerning the classification of oral-genital contact will be beneficial for communication in clinical, educational and research settings—provided that clinicians, educators and researchers are cognizant of lay views. However, disassociating oral-genital contact from sexual activity may have adverse public health implications if those who engage in this behavior become less mindful of the potential for transmission of STDs.

Given the importance of unambiguous language and the potential implications of reclassifying oral-genital contact, along with evidence suggesting a shift in behaviors and attitudes, the purpose of this study was to examine whether the classification of oral-genital contact has changed over time. We hypothesized that young adults would be less likely now than they were in the past to classify oral-genital contact as sex, and that this change would be larger than any other changes that may have occurred in views of what constitutes sex. We tested this hypothesis by replicating the 19912 and 1999–20011 studies on what behaviors constitute sex.


In the fall of 2007, a convenience sample was recruited from among undergraduate students enrolled in a human sexuality course, which was a general education elective at a large state university. The instructor announced in class that a link to the computer-administered survey would be posted on the course Web site for four days, and a reminder e-mail was sent to students who had not completed the survey after three days. Students who participated received one bonus point toward their grade, which represented 0.2% of their total grade. In all, 477 students (80% of those enrolled) completed the survey.

Respondents’ views of what constitutes sex were assessed with the question “Would you say you ‘had sex’ with someone if the most intimate behavior you engaged in was” each of 11 behaviors;2 response options were yes and no, and respondents were not permitted to skip any questions. To avoid having the order of behaviors influence responses or giving the impression of a hierarchical relationship among the behaviors, the computer presented behaviors in random order to each respondent.

Several studies, including the ones we are replicating here,1,2 have found modest but consistent differences in how males and females define sex. Specifically, males have been more likely than females to consider a broad array of behavior sex. Therefore, we, too, examine gender differences in definitions of sex.

Sexual experience was not included in the 1991 study.2 However, because it has been associated with definitions of virginity and abstinence,9–10 we wanted to explore how it may be related to definitions of sex. Therefore, we collected self-reported data on the numbers of partners of the opposite sex with whom respondents had had oral-genital and oral-anal contact, and penile-vaginal and penile-anal intercourse.

We conducted chi-square analyses to assess whether males’ and females’ sexual experiences differed, independent samples t tests to assess gender differences in lifetime number of partners and chi-square analyses to assess gender differences concerning beliefs about what constitutes sex. We also conducted chi-square analyses to compare our data with the data collected in 1991, to assess change over time.2 Magnitude of change in chi-square and t tests was interpreted according to Cohen's guidelines.11 For chi-square tests, a coefficient of 0.1 represents a small effect, 0.3 a medium effect and 0.5 or higher a large effect; for t tests, the corresponding cutoffs are 0.01, 0.06 and 0.14, respectively. Finally, we used logistic regression to identify predictors of beliefs concerning whether oral-genital contact constituted sex.


Sample Characteristics

The sample consisted of 328 females and 149 males. Their ages ranged from 18 to 41 (mean, 20.7; standard deviation, 2.4), but the vast majority (98%) were 24 or younger. Most respondents (87%) were white, 8% were black and the remaining 5% were of other races or ethnicities. Some 97% self-identified as heterosexual. Females represented a greater share of the sample than of all undergraduates enrolled at the university (69% vs. 51%), but respondents' racial and ethnic distribution reflected that of the larger student population.

Although 98% of the sample had never been married, relationship status was varied: Fifty-four percent of respondents were neither cohabiting nor in a committed relationship, 37% were not cohabiting but in a committed relationship, and 8% were cohabiting with an intimate partner. Thirty-one percent of respondents were Catholic, 21% were Baptist, 10% were Methodist, 12% were non-denominational Christians, 9% had no religious preference, 4% were agnostic or atheist, and the remaining 14% were affiliated with other religions or denominations. Among those who expressed a religious preference, 23% identified very strongly with their religion, 43% somewhat strongly, 24% somewhat weakly and 9% very weakly.

Overall, the composition of our sample was reasonably similar to that of the sample in the 1991 study.2 Members of the earlier sample were 599 randomly recruited undergraduate students (58% of those recruited) at a large state university 180 miles from our university. Their mean age was the same as the mean in our sample (20.7 years), and 96% of them reported a heterosexual orientation. The earlier sample had a more even gender balance than ours (59% of respondents were females), but it was slightly less racially diverse: Ninety-two percent of respondents were white, and 4% black. Relationship and cohabitation status, religious affiliation and religiosity were not reported for the 1991 sample. Fewer descriptive characteristics were provided for the 1999–2001 sample, but on the demographic characteristics provided, those respondents also appear to have been similar to ours: Ninety percent were white, they were 18–24 years old, 96% were heterosexual and 64% were in a romantic relationship.1

Sexual Experiences

Females were more likely than males to report having had at least one experience with three of the sexual behaviors assessed (Table 1): giving oral-genital stimulation (89% vs. 78%), receiving oral-anal stimulation (17% vs. 7%) and having penile-vaginal intercourse (85% vs. 75%). However, according to Cohen's criteria, these differences were small (coefficients, 0.12–0.15—not shown). Chi-square analyses (not shown) found no associations between respondents' sexual experience and assessments of whether behaviors they had experienced constituted sex.

Females also reported having given oral-genital stimulation to more partners than males had (mean, 3.4 vs. 2.5—Table 1). Similarly, males reported having received oral-genital stimulation from more partners than females (4.1 vs. 3.0). Again, although these differences were statistically significant, they were small (coefficients, 0.12 and 0.17—not shown) Females and males reported similar numbers of lifetime penile-vaginal intercourse partners (3.7–3.8); the numbers of reported partners for other sexual behaviors were low and did not differ by gender.

Behaviors That Constitute Sex

The majority of respondents indicated that having had penile-vaginal and penile-anal intercourse would constitute having “had sex” (98% and 78%, respectively—Table 2). The behavior that was classified as sex the next most frequently was oral-genital contact, but only about 20% of respondents gave it this classification. All other assessed behaviors were thought of as sex by roughly 5–10% of respondents. Males were significantly more likely than females to say that having “had sex” includes having had a partner touch their genitals (13% vs. 7%), having orally stimulated a partner's breasts or nipples (9% vs. 4%) and having touched a partner's breasts or nipples (8% vs. 3%). All of these differences were small (coefficients, 0.10–0.12).

Our comparisons of the 2007 data and the 1991 data revealed some significant variation between the two samples, but the differences generally were small (coefficients, 0.07–0.10). The notable exception was that respondents in 2007 were only about half as likely as those in 1991 to classify oral-genital contact as sex; this difference was consistent for both sexes and for both giving and receiving oral stimulation. These differences (coefficients, 0.20–0.24) were more than twice as large as any others between the two samples. Informal post hoc discussion with some respondents suggested that young adults think of oral-genital contact as “messing around” rather than sex per se.

Logistic regression analyses (not shown) did not find any demographic predictors of whether one views giving or receiving oral-genital stimulation as having had sex. Similarly, beliefs did not vary according to whether respondents had experienced oral-genital contact or according to the number of partners with whom they had had engaged in this behavior.


Our respondents were unambiguous in their characterization of oral-genital contact: Only 20% would classify this activity as having “had sex.” By contrast, in 19912 and again in 1999–2001,1 samples similar to ours expressed considerable ambivalence; 40% characterized oral-genital contact as having “had sex.” The magnitude of change in the classification of oral-genital contact supports our hypothesis that a shift has occurred in sociocultural conceptualizations of this behavior. Although data are not available prior to 1991, the consistency between the 1991 and the 1999–2001 data suggests that this change is not part of a long-term trend.

Unlike respondents in the previous samples, our respondents were adolescents after the Clinton-Lewinsky era, which our comparisons of data over time suggest may have been a turning point in conceptualizations of oral-genital contact. The dramatic and sudden shift in attitudes toward oral-genital contact can therefore be termed the Clinton-Lewinsky effect.

The Clinton-Lewinsky era… may have been a turning point in conceptualizations of [oral sex].

This is not to say that other factors have not also contributed to the reclassification of oral-genital contact. The amount of information about sex that young adults received from professionals and the media increased between 1990 and 2006.12 Accordingly, school-based sex education programs and popular media may have contributed to the changing conceptualization of oral-genital contact.

Some research has associated exposure to popular media with early initiation of sexual behaviors,13 but little is known about the effects that exposure to sexual content through movies, magazines, video games, the Internet and radio have on adolescent sexual attitudes and behaviors.14 Sexual content on television, however, appears to predict early initiation of sexual behaviors and generally plays an important role in the sexual socialization of adolescents and young adults.15–16 Nevertheless, although the amount of sexual content on television nearly doubled between 1998 and 2005, oral sex is portrayed much less often than other sex acts.16 Thus, television is unlikely to be directly responsible for the shift in classification of oral-genital contact away from sex.

Halpern-Felsher et al. found that adolescents view oral-genital contact as more acceptable than penile-vaginal intercourse, and suggested that this may reflect, in part, sex education programs’ primary focus on penile-vaginal intercourse.8 This line of reasoning may have some merit for explaining the shift we have uncovered, especially considering that the shift paralleled a surging emphasis on abstinence-only education by the administration of President George W. Bush. The emphasis of sex education programs—even comprehensive sex education programs—on penile-vaginal intercourse at the expense of oral-genital contact may be justified, however, if these programs’ primary objectives are to reduce the incidence of unplanned pregnancy and STDs. (Oral-genital contact carries a risk for STD transmission, but penile-vaginal contact carries a much greater risk.17) Regardless, additional studies are needed that examine the role of various forms of sex education in shaping conceptualizations of oral-genital contact relative to other forms of sexual expression.


Our sample was not representative of the young adult population, and the findings therefore have limited generalizability. Also, given the consistency across three previous studies concerning whether oral-genital contact constitutes sex,1–2,6 an alternative explanation for the changes we found is that some unmeasured characteristic of our sample influenced students’ responses. This seems unlikely, however, given the similarities between our sample and at least two previous ones on key demographic characteristics, as well as the consistency between our sample and the previous ones concerning the classification of other behaviors. Moreover, our findings appear to be consistent with behavioral and attitudinal changes identified by others.7–8 Nevertheless, definitive conclusions should not be drawn about the reclassification of oral-genital contact until our results are replicated with more representative samples of young adults.

We also caution against inferring from these data that the prevalence of or decision making about oral-genital contact has changed. Our findings indicate that smaller proportions of young adults classify oral-genital contact as sex now than did so in previous cohorts, and hypotheses can be generated linking these findings with behavioral change; nevertheless, our data do not identify or imply changes in behavior. Any speculation concerning behavioral changes associated with our findings will need empirical validation.


Regardless of its origins, the shift in thinking about oral-genital contact has public health implications. After penile-vaginal and penile-anal intercourse—both of which the majority of respondents in 1991, 1999–2001 and 2007 classified as “sex”—oral-genital contact represents the next most risky sexual behavior. Specifically, oral-genital contact carries a transmission risk for herpes, syphilis, gonorrhea, human papillomavirus, intestinal parasites, hepatitis A and HIV.17 Despite these risks, roughly 20% of adolescents and 10% of young adults do not know that STDs can be transmitted via oral-genital contact, and use of condoms or dental dams with this behavior is rare.18–21 As oral-genital stimulation becomes disassociated from sex and increasingly thought of as “messing around,” akin to touching and manual stimulation of erogenous zones (behaviors that have very low risk of STD transmission), we speculate that those who engage in this behavior may become increasingly unmindful of the health risks associated with oral-genital contact. Sex education programs can help them minimize their risk by giving increased attention to the role of this behavior in STD transmission and to appropriate preventive measures.