Discrepancies between men and women in reporting number of sexual partners: A summary from four countries

Abstract

Men and women in national surveys from four countries, the United States, Canada, Great Britain, and Norway, give mutually inconsistent reports of numbers of opposite‐gender sexual partners. In all cases the number of female partners reported by men exceeds the number of male partners reported by women. Gender difference in reporting bias seems to be the most plausible explanation for the discrepancies.     

Younger and Older Adults Collaborating on Retelling Everyday Stories

Contracting a sexually transmitted disease (STD) is one of the most serious public health issues for adolescents and young adults; rates of STDs among American Indian youth are among the highest of any racial or ethnic group in the United States. Although it is one of the key risk factors for spreading STDs, little is known about individual development of multiple sexual partners in any ethnic group. Drawing from social cognitive theory, this study used latent growth curve modeling with a sample of 518 American Indian adolescents and young adults to delineate the relationship across 4 years between youths' confidence in resisting risk and the number of sexual partners they had. The development of resistive efficacy was similar across genders: Although women reported higher levels at all time points, both genders increased across time. Men reported relatively stable levels of sexual partners; women had fewer sexual partners initially, but the number increased significantly and then decelerated. Further, the 2 trajectories had significant interdependence: Both intercepts and slopes were negatively related to each other across construct, suggesting that increasing resistive efficacy was related to decreasing number of sexual partners.     

Prevalence of and risk factors associated with alcohol abuse in Moshi, northern Tanzania

This study aimed to assess the prevalence of and risk factors associated with alcohol abuse among women and men in Moshi in northern Tanzania. Alcohol abuse was measured by a CAGE score of 2-4, versus 0-1 for no alcohol abuse (Ewing, 1984). Crude and adjusted logistic regression models determined odds ratios (OR) and 95% confidence intervals (95% CI) of alcohol abuse by characteristics of, respectively, women with partners (n=1200), women without partners (n=614) and men (n=788) (women's partners). Prevalence of alcohol abuse was 7.0% (95% CI: 5.6-8.4) among women with partners, 9.3% (95% CI: 7.0-11.6) among women without partners, and more than double among men at 22.8% (95% CI: 19.9-25.8). In general, Christians had higher alcohol abuse than Muslims or other religions, as did Chagga men compared with men of other ethnic groups. Other socio-demographic characteristics, such as education or income, were not significant. Sexual behaviours were significant predictors of alcohol abuse. For example, women without partners who reported more than two partners in the last year had higher alcohol abuse compared with women reporting no partners (OR=8.75; 95% CI: 2.37-32.31), as did men reporting it is 'OK to hit a partner' for any reason (OR=1.79; 95% CI: 1.16-2.77) compared with men who did not. HIV-1 infection was not significantly associated with alcohol abuse by women or men. The Christian Church in Moshi should consider raising awareness about the harmful effects of high alcohol use among its adherents. Comprehensive programmes focusing on reducing number of partners and alcohol use, particularly by men, are needed in this community.     

Gender differences in the risk of HIV infection among persons reporting abstinence, monogamy, and multiple sexual partners in northern Tanzania

Background

Monogamy, together with abstinence, partner reduction, and condom use, is widely advocated as a key behavioral strategy to prevent HIV infection in sub-Saharan Africa. We examined the association between the number of sexual partners and the risk of HIV seropositivity among men and women presenting for HIV voluntary counseling and testing (VCT) in northern Tanzania.

Methodology/ Principal Findings

Clients presenting for HIV VCT at a community-based AIDS service organization in Moshi, Tanzania were surveyed between November 2003 and December 2007. Data on sociodemographic characteristics, reasons for testing, sexual behaviors, and symptoms were collected. Men and women were categorized by number of lifetime sexual partners, and rates of seropositivity were reported by category. Factors associated with HIV seropositivity among monogamous males and females were identified by a multivariate logistic regression model. Of 6,549 clients, 3,607 (55%) were female, and the median age was 30 years (IQR 24–40). 939 (25%) females and 293 (10%) males (p<0.0001) were HIV seropositive. Among 1,244 (34%) monogamous females and 423 (14%) monogamous males, the risk of HIV infection was 19% and 4%, respectively (p<0.0001). The risk increased monotonically with additional partners up to 45% (p<0.001) and 15% (p<0.001) for women and men, respectively with 5 or more partners. In multivariate analysis, HIV seropositivity among monogamous women was most strongly associated with age (p<0.0001), lower education (p<0.004), and reporting a partner with other partners (p = 0.015). Only age was a significant risk factor for monogamous men (p = 0.0004).

Interpretation

Among women presenting for VCT, the number of partners is strongly associated with rates of seropositivity; however, even women reporting lifetime monogamy have a high risk for HIV infection. Partner reduction should be coupled with efforts to place tools in the hands of sexually active women to reduce their risk of contracting HIV.     

Changes in women's sexual interests and their partners' mate-retention tactics across the menstrual cycle: evidence for shifting conflicts of interest

Because ancestral women could have obtained genetic benefits through extra-pair sex only near ovulation, but paid costs of extra-pair sex throughout the cycle, one might expect selection to have shaped female interest in partners, other than primary partners, to be greater near ovulation than during the luteal phase. Because men would have paid heavier costs if their partners had extra-pair sex near ovulation, one might also expect selection to have shaped males' efforts to track their primary partners' whereabouts to be increased near ovulation, relative to the luteal phase. Women filled out questionnaires about their sexual interests and their partners' mate-retention tactics twice: once within 5 days before a lutenizing hormone surge and once during the luteal phase. Results showed that: (i) women reported greater sexual interest in, and fantasy about, non-primary partners near ovulation than during the luteal phase; (ii) women did not report significantly greater sexual interest in, and fantasy about, primary partners near ovulation; (iii) women reported that their primary partners were both more attentive and more proprietary near ovulation.     

Testosterone Levels Are Negatively Associated with Childlessness in Males,but Positively Related to Offspring Count in Fathers

Variation in testosterone (T) is thought to affect the allocation of effort between reproductive and parenting strategies. Here, using a large sample of elderly American men (n = 754) and women (n = 669) we examined the relationship between T and self-reported parenthood, as well as the relationship between T and number of reported children. Results supported previous findings from the literature, showing that fathers had lower T levels than men who report no children. Furthermore, we found that among fathers T levels were positively associated with the number of children a man reports close to the end of his lifespan. Results were maintained when controlling for a number of relevant factors such as time of T sampling, participant age, educational attainment, BMI, marital status and reported number of sex partners. In contrast, T was not associated with either motherhood or the number of children women had, suggesting that, at least in this sample, T does not influence the allocation of effort between reproductive and parenting strategies among women. Findings from this study contribute to the growing body of literature suggesting that, among men, pair bonding and paternal care are associated with lower T levels, while searching and acquiring sex partners is associated with higher T levels.     

Sexual behaviour, contraceptive practice and knowledge of AIDS of Oxford University students

In 1987, a questionnaire was sent to 584 undergraduate students at Oxford University requesting information about their sexual behavior and contraceptive practices as well as the impact of acquired immunodeficiency syndrome (AIDS) on both these factors. Of the 374 responders, 65% of the women and 62% of the men had experienced sexual intercourse; 1st intercourse had occurred at ages 16-20 years for 89% of the experienced women and 83% of the men. For 36% of women and 37% of men intercourse had been with 1 partner only, for 28% of women and 27% of men with 2-3 partners, and for 36% of both men and women with more than 3 partners. 27% of the women reported no contraceptive was used at the time of 1st intercourse. During the 4 weeks preceding completion of the questionnaire, 15% of sexually active female undergraduates reported not using adequate contraception. Users during this period selected the pill (64%), condom (19%), IUD or diaphragm (9%), or withdrawal/rhythm (8%). General knowledge about AIDS was highly accurate among these students. Most students considered themselves to be at lower risk of contracting AIDS than others of their age and sex. Of the 78% of students describing themselves as at lower than average risk, 14% had had intercourse with more than 3 partners, while 50% of the 20% of students who ranked themselves as at average risk had this number of partners. Only 2% placed themselves as at above average risk, and 65% of these students had had more than 3 sexual partners. Of students who were sexually active, 35% of the females and 44% of the males indicated they are now more likely to use a condom because of fear of AIDS. 49% of the females and 30% of the males indicated they had, or would have, fewer sexual partners because of the AIDS risk. However, there was no association between increased likelihood of condom use and the total number of sexual partners and having had intercourse with someone in a high-risk group for AIDS (prostitutes). Overall, however, these findings suggest that the AIDS threat is producing reductions in high-risk behaviors.     

Are men more promiscuous than women?

In spite of the unassailable logic that every new coital partner a man has is also a new partner for the woman concerned, men typically claim more sexual partners than women. If these claims are correct, can prostitutes and other hypersexual women account for this slippage? The present study examines whether the incidence of such women is sufficient to explain the discrepancy in number of lifetime partners claimed by men and women.     

Male sexual attractiveness predicts differential ovulatory shifts in female extra-pair attraction and male mate retention

Because ancestral women faced trade-offs in choosing mates, they may have evolved to pursue a dual-mating strategy in which they secured investment through one partner and obtained good genes through others. The dual-mating theory predicts that women will display greater interest in extra-pair sex near ovulation, especially if they are mated to a primary male partner who is low in sexual attractiveness. Forty-three normally ovulating women rated their partner's sexual attractiveness and separately reported their own desires and their partner's mate retention behaviors at high and low fertility (confirmed using luteinizing hormone tests). In the high-fertility session relative to the low, women who assessed their partners as being lower in sexual attractiveness reported greater extra-pair desires and more expressed love and attention from their male partners. Women's desire for their own partners did not differ significantly between high and low-fertility sessions.     

Testosterone levels and their associations with lifetime number of opposite sex partners and remarriage in a large sample of American elderly men and women

Testosterone (T) has been argued to modulate mating and parenting behavior in many species, including humans. The role of T for these behaviors has been framed as the challenge hypothesis. Following this hypothesis, T should be positively associated with the number of opposite sex partners a male has. Indeed research in humans has shown that T is positively related to the number of opposite sex partners a young man has had. Here we test, in both men and women, whether this relationship extends to the lifetime number of sex partners. We also explored whether or not T was associated with current marital status, partnership status and whether or not the participant remarried. Using a large sample of elderly men and women (each sample n > 700), we show that T is positively and sizably associated with the number of opposite sex partners in men. When controlling for potential confounding variables such as educational attainment, age, BMI, ethnicity, specific use of a medication and time of sampling this effect remained. For women, the relationship between T and number of opposite sex partners was positive but did not prove to be robust. In both men and women there was no evidence for an association between T and current marital status and partnership status (being in a relationship or not). However, remarriage was positively associated with T, but only in males. Results are discussed with reference to the literature on T and sex partners, remarriage and more broadly the challenge hypothesis.     

What Distinguishes Women with Unusually High Numbers of Sex Partners?

We recruited two groups of women who differed in their number of lifetime sex partners in order to investigate several hypotheses related to female sociosexuality. Specifically, we explored whether women who engage in casual sex have low mate value, are especially likely to have come from stressful family environments, or are masculine in other respects besides their interest in casual sex. Women with many partners were not lower than other women on direct or indirect indicators of mate value. Nor were they more likely to recall adverse family environments during childhood. On several measures related to masculinity, women with many sex partners were elevated compared with other women.     

Risk behaviours for HIV infection among drug users in prison.

OBJECTIVE--To study a group of injecting drug users to establish the degree of illicit drug use in prisons, the prevalence of risk behaviours for HIV infection, and the uptake of treatment for drug dependency with drugs within the prison system. DESIGN--Anonymous, self administered, questionnaire. SETTING--Two drug agencies in central London; one operating a scheme for exchanging needles, and the other offering drug advice and information. SUBJECTS--50 (42 Men, eight women) self selected injecting drug users (mean age 31.2 (range 21-42)), all of whom had been held in custody at some time since 1982. MAIN OUTCOME MEASURES--Details about periods served in custody since 1982; the number of respondents who took drugs (orally or by injection), either illicitly or prescribed, while in prison and the types of substances taken; the respondents'' sexual activity in prison and between periods in custody. RESULTS--The average time spent in custody before the study was 20.6 months (range 1-72). Most prosecutions were directly or indirectly related to drug taking. 47 Of the 50 respondents reported taking at least one illicit drug while in custody; 33 by injection, 26 of whom had shared injecting equipment. 30 Had been treated for drug dependency by the prescribing of drugs while in prison. While in custody, one woman and four men (with a mean of seven (range 2-16) male partners) had had sex. Between periods spent in custody, men reported having a mean of eight (range 0-90) female partners and women a mean of one (range 0-3) male partner. Three men had had sex with other men, with a mean of six (range 2-11) partners. Since their last period in custody, men had had a mean of two (range 0-18) female partners and women had had a mean of two (range 1-3) male partners. Five men had also had male partners. CONCLUSIONS--A high prevalence of injecting and sexual risk behaviours among injecting drug users within and between periods in custody has been shown. Most of these offenders continued to take drugs while in custody, and just over half not only injected drugs but shared equipment. Some of the male prisoners compounded their risk of HIV infection by engaging in sexual activity with multiple partners. Prisoners who then have multiple sexual partners after release place their partners in the community at particular risk of HIV infection. Although many of the drug users were prescribed drugs for their dependency, limited access to appropriate treatment, counselling, and health education may compound the situation.     

Human immunodeficiency virus infection,hepatitis B virus infection,and sexual behaviour of women attending a genitourinary medicine clinice

During the six months immediately after a public information campaign about the acquired immune deficiency syndrome 1115 women who attended a genitourinary medicine clinic in west London were tested for antibodies to the human immunodeficiency virus (HIV). Three women (0·27%) were positive, and all three were regular sexual partners of men with high risk lifestyles—two intravenous drug users and one bisexual. A consecutive series of 647 women from the cohort was tested for antibodies for hepatitis B core antigen: 27 were positive, of whom six had been born in the United Kingdom and were not known to have been at risk. The two women who were seropositive for HIV who completed a questionnaire on their sexual behaviour before they were tested reported both anal and oral receipt of semen and were in the upper fifth percentile for lifetime sexual partners. More than half (53%) of 424 women who reported that they had non-regular sexual partners never used a condom.It is concluded that heterosexual women in London are at a low risk of becoming infected with HIV.     

Higher variability in the number of sexual partners in males can contribute to a higher prevalence of sexually transmitted diseases in females

By examining published, empirical data we show that men and women consistently differ in the shape of the distribution of the number of sexual partners. The female distribution is always relatively narrow—variance is low—with a big majority of women having a number of partners close to the average. The male distribution is much wider—variance is high—with many men having few sex partners and many others having more partners than most females.Using stochastic modelling we demonstrate that this difference in variance is, in principle, sufficient to cause a difference in the gender prevalence of sexually transmitted diseases: compared to the situation where the genders have identical sex partner distributions, men will reach a lower equilibrium value, while women will stay at the same level (meaning that female prevalence becomes higher than male). We carefully analyse model behaviour and derive approximate expressions for equilibrium prevalences in the two different scenarios. We find that the size of the difference in gender prevalence depends on the variance ratio (the ratio between the variances of the male and female sex partner distributions), on the expected number of life-time partners, and on the probability of disease transmission. We note that in addition to humans, the variance phenomenon described here is likely to play a role for sexually transmitted diseases in other species also.We also show, again by examining published, empirical data, that the female to male prevalence ratio increases with the overall prevalence of a sexually transmitted disease (i.e., the more widespread the disease, the more women are affected). We suggest that this pattern may be caused by the effect described above in highly prevalent sexually transmitted diseases, while its impact in low-prevalence epidemics is surpassed by the action of high-risk individuals (mostly males).     

Human vocal behavior within competitive and courtship contexts and its relation to mating success

Beyond the linguistic content of their speech, speakers of both sexes convey diverse biological and psychosocial information through their voices, which are important when assessing potential mates and competitors. However, studies investigating the relationships between mating success and acoustic inter-individual differences are scarce. In this study, we investigated such relationships in both sexes in courtship and competitive interactions—as they correspond to the two different types of sexual selection—using an experimental design based on a simulated dating game. We assessed which type of sexual selection best predicted mating success, here defined as the self-reported number of sexual partners within the past year. Our results show that only acoustic inter-individual differences in the courtship context for both men and women predicted their mating success. Men displaying faster articulation rate and louder voices reported significantly more sexual partners; in contrast, men displaying higher intonation reported a greater negative effect of roughness and breathiness on their mating success. Women who displayed relatively less breathy voices and shorter speech duration reported significantly fewer sexual partners. These novel findings are discussed in light of the mate choice context and the relative contribution of both types of sexual selection shaping acoustic features of speech.     

The Contribution of Emotional Partners to Sexual Risk Taking and Violence among Female Sex Workers in Mombasa,Kenya: A Cohort Study

Objectives

To assess sexual risk-taking of female sex workers (FSWs) with emotional partners (boyfriends and husbands), compared to regular and casual clients. Experiences of violence and the degree of relationship control that FSWs have with emotional partners are also described.

Design

Cohort study with quarterly follow-up visit over 12-months.

Methods

Four hundred HIV-uninfected FSWs older than 16 years were recruited from their homes and guesthouses in Mombasa, Kenya. A structured questionnaire assessed participant characteristics and study outcomes at each visit, and women received risk-reduction counselling, male and female condoms, and HIV testing.

Results

Four or more unprotected sex acts in the past week were reported by 21.3% of women during sex with emotional partners, compared to 5.8% with regular and 4.8% with casual clients (P<0.001). Total number of unprotected sex acts per week was 5–6-fold higher with emotional partners (603 acts with 259 partners) than with regular or casual clients (125 acts with 456, and 98 acts with 632 clients, respectively; P<0.001). Mostly, perceptions of “trust” underscored unprotected sex with emotional partners. Low control over these relationships, common to many women (36.9%), was linked with higher partner numbers, inconsistent condom use, and being physically forced to have sex by their emotional partners. Half experienced sexual or physical violence in the past year, similarly associated with partner numbers and inconsistent condom use.

Conclusions

High-risk sexual behaviour, low control and frequent violence in relationships with emotional partners heighten FSWs'' vulnerability and high HIV risk, requiring targeted interventions that also encompass emotional partners.     

Forced Sexual Experiences as Risk Factor for Self-Reported HIV Infection among Southern African Lesbian and Bisexual Women

Even though women who have sex with women are usually understood to be at no or very low risk for HIV infection, we explored whether lesbian and bisexual women in a geographical area with high HIV prevalence (Southern Africa) get tested for HIV and whether, among those women who get tested, there are women who live with HIV/AIDS. The study was conducted in collaboration with community-based organizations in Botswana, Namibia, South Africa and Zimbabwe. Data were collected via written surveys of women who in the preceding year had had sex with a woman (18 years and older; N = 591). Most participating women identified as lesbian and black. Almost half of the women (47.2%) reported ever having had consensual heterosexual sex. Engagement in transactional sex (lifetime) was reported by 18.6% of all women. Forced sex by men or women was reported by 31.1% of all women. A large proportion of the women reported to ever have been tested for HIV (78.3%); number of lifetime female and male partners was independently associated with having been tested; women who had engaged in transactional sex with women only or with women and men were less likely to have been tested. Self-reported HIV prevalence among tested women who knew their serostatus was 9.6%. Besides age, the sole independent predictor of a positive serostatus was having experienced forced sex by men, by women, or by both men and women. Study findings indicate that despite the image of invulnerability, HIV/AIDS is a reality for lesbian and bisexual women in Southern Africa. Surprisingly, it is not sex with men per se, but rather forced sex that is the important risk factor for self-reported HIV infection among the participating women. HIV/AIDS policy should also address the needs of lesbian, bisexual and other women who have sex with women.     

Predictors of Inconsistent Condom Use among a Hard to Reach Population of Young Women with Multiple Sexual Partners in Peri-Urban South Africa

Background

Evidence suggests that multiple concurrent sexual partnering may be a key driver of the high HIV prevalence among young women in South Africa. However, little is known about whether and to what extent women who have multiple sexual partners also engage in other high risk sexual behaviors such as inconsistent condom use. And yet, multiple concurrent sexual partnering is of little epidemiological relevance if all partners in these sexual networks use condoms consistently. This study assesses the prevalence of sexual risk behaviors and HIV, and predictors of inconsistent condom use among women aged 16–24 with multiple sexual partners in a peri-urban setting in South Africa.

Methods

We used Respondent Driven Sampling, a sampling strategy for hard-to-reach populations to recruit 259 women aged 16–24 in a bio-behavioral cross-sectional survey in the Western Cape province. Estimates of population proportions and 95% confidence intervals (CIs) were calculated using the Respondent-Driven Sampling Analysis Tool 5.6 (RDSAT). The primary outcome was inconsistent condom use in the past three months.

Results

Young women reported an average of 7 partners in the past 3 months and a high prevalence of sexual risk behaviors: concurrency (87%), transactional sex (91%) and age mixing (59%). Having >5 sexual partners in the last 3 months doubled the risk of unprotected sex (OR 2.43, CI 1.39–4.25). HIV prevalence was 4% among 16–19 year olds, increasing threefold (12%) at age 20–24.

Discussion

Multiple sexual partnering, where a high number of partners are acquired in a short space of time, is a fertile context for unprotected and risky sexual behavior. The young women featured in this survey present with a constellation of high-risk sexual behaviors that cluster to form a risk syndrome. Carefully tailored repeat bio-behavioral surveillance surveys are recommended for this sub-population.     

“When I Was Circumcised I Was Taught Certain Things”: Risk Compensation and Protective Sexual Behavior among Circumcised Men in Kisumu,Kenya

Background

Male circumcision has been shown to reduce the transmission of HIV from women to men through vaginal sex by approximately 60%. There is concern that men may engage in risk compensation after becoming circumcised, diminishing the benefits of male circumcision.

Methods and Findings

We conducted qualitative interviews with 30 sexually active circumcised men in Kisumu, Kenya from March to November 2008. Most respondents reported no behavior change or increasing protective sexual behaviors including increasing condom use and reducing the number of sexual partners. A minority of men reported engaging in higher risk behaviors either not using condoms or increasing the number of sex partners. Circumcised respondents described being able to perform more rounds of sex, easier condom use, and fewer cuts on the penis during sex.

Conclusions

Results illustrate that information about MC''s protection against HIV has disseminated into the larger community and MC accompanied by counseling and HIV testing can foster positive behavior change and maintain sexual behavior.     

HIV Incidence in a Cohort of Women at Higher Risk in Beira,Mozambique: Prospective Study 2009–2012

Background

HIV is prevalent in Sofala Province, Mozambique. To inform future prevention research, we undertook a study in the provincial capital (Beira) to measure HIV incidence in women at higher risk of HIV and assess the feasibility of recruiting and retaining them as research participants.

Methods

Women age 18–35 were recruited from schools and places where women typically meet potential sexual partners. Eligibility criteria included HIV-seronegative status and self-report of at least 2 sexual partners in the last month. History of injection drug use was an exclusion criterion, but pregnancy was not. Participants were scheduled for monthly follow-up for 12 months, when they underwent face-to-face interviews, HIV counseling and testing, and pregnancy testing.

Results

387 women were eligible and contributed follow-up data. Most were from 18–24 years old (median 21). Around one-third of participants (33.8%) reported at least one new sexual partner in the last month. Most women (65.5%) reported not using a modern method of contraception at baseline. Twenty-two women seroconverted for a prospective HIV incidence of 6.5 per 100 woman-years (WY; 95% confidence interval (CI): 4.1–9.9). Factors associated with HIV seroconversion in the multivariable analysis were: number of vaginal sex acts without using condoms with partners besides primary partner in the last 7 days (hazard ratio (HR) 1.7; 95% CI: 1.2–2.5) and using a form of contraception at baseline other than hormonal or condoms (vs. no method; HR 25.3; 95% CI: 2.5–253.5). The overall retention rate was 80.0% for the entire follow-up period.

Conclusions

We found a high HIV incidence in a cohort of young women reporting risky sexual behavior in Beira, Mozambique. HIV prevention programs should be strengthened. Regular HIV testing and condom use should be encouraged, particularly among younger women with multiple sexual partners.