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Concept: Human sexuality

359

Adolescence is marked by the emergence of human sexuality, sexual identity, and the initiation of intimate relations; within this context, abstinence from sexual intercourse can be a healthy choice. However, programs that promote abstinence-only-until-marriage (AOUM) or sexual risk avoidance are scientifically and ethically problematic and-as such-have been widely rejected by medical and public health professionals. Although abstinence is theoretically effective, in actual practice, intentions to abstain from sexual activity often fail. Given a rising age at first marriage around the world, a rapidly declining percentage of young people remain abstinent until marriage. Promotion of AOUM policies by the U.S. government has undermined sexuality education in the United States and in U.S. foreign aid programs; funding for AOUM continues in the United States. The weight of scientific evidence finds that AOUM programs are not effective in delaying initiation of sexual intercourse or changing other sexual risk behaviors. AOUM programs, as defined by U.S. federal funding requirements, inherently withhold information about human sexuality and may provide medically inaccurate and stigmatizing information. Thus, AOUM programs threaten fundamental human rights to health, information, and life. Young people need access to accurate and comprehensive sexual health information to protect their health and lives.

Concepts: United States, Women's rights, Reproductive rights, Human sexual behavior, Federal government of the United States, Health, Sexual intercourse, Human sexuality

279

Sex and disgust are basic, evolutionary relevant functions that are often construed as paradoxical. In general the stimuli involved in sexual encounters are, at least out of context strongly perceived to hold high disgust qualities. Saliva, sweat, semen and body odours are among the strongest disgust elicitors. This results in the intriguing question of how people succeed in having pleasurable sex at all. One possible explanation could be that sexual engagement temporarily reduces the disgust eliciting properties of particular stimuli or that sexual engagement might weaken the hesitation to actually approach these stimuli.

Concepts: Human sexual behavior, Human sexuality, Vagina, Orgasm, Sexual arousal, Sexual intercourse

226

Concern about young people’s sexuality is focused on the need to prevent harmful outcomes such as sexually transmitted infections and unplanned pregnancy. Although the benefit of a broader perspective is recognized, data on other aspects of sexuality, particularly sexual function, are scant. We sought to address this gap by measuring the population prevalence of sexual function problems, help seeking, and avoidance of sex in young people.

Concepts: Pregnancy, Oral sex, Sexually transmitted disease, Human sexuality, Sexuality, Sexual intercourse, Human sexual behavior

212

Social networks based on dyadic relationships are fundamentally important for understanding of human sociality. However, we have little understanding of the dynamics of close relationships and how these change over time. Evolutionary theory suggests that, even in monogamous mating systems, the pattern of investment in close relationships should vary across the lifespan when post-weaning investment plays an important role in maximising fitness. Mobile phone data sets provide a unique window into the structure and dynamics of relationships. We here use data from a large mobile phone dataset to demonstrate striking sex differences in the gender-bias of preferred relationships that reflect the way the reproductive investment strategies of both sexes change across the lifespan, i.e. women’s shifting patterns of investment in reproduction and parental care. These results suggest that human social strategies may have more complex dynamics than previously assumed and a life-history perspective is crucial for understanding them.

Concepts: Natural selection, Human sexuality, Sexual reproduction, Reproduction, Interpersonal relationship, Male, Evolution, Sex

172

Male genital satisfaction is an important aspect of psychosocial and sexual health. The Index of Male Genital Image (IMGI) is a new scale that measures perceptions of male genitalia. We aim to characterize genital satisfaction using the IMGI and correlate dissatisfaction with sexual activity. We conducted a nationally representative survey of non-institutionalized adults aged 18-65 years residing in the U.S. In total, 4198 men completed the survey and 3996 (95.2 %) completed the IMGI. Men reported highest satisfaction with the shape of their glans (64 %), lowest satisfaction with the length of their flaccid penis size (27 %), and neutrality with the scent of their genitals (44 %). No demographic characteristics (age, race, sexual orientation, education, location, and income) were significantly associated with genital dissatisfaction. Men who were dissatisfied with their genitals were less likely to report being sexually active (73.5 %) than those who were satisfied (86.3 %). Penetrative vaginal sex (85.2 vs. 89.5 %) and receptive oral intercourse (61.0 vs. 66.2 %) were reported less by dissatisfied men. Overall, most U.S. men were satisfied with their genitals; however, a subset (14 %) report low genital satisfaction, which included men of all ages, races, and socioeconomic groups. Low genital satisfaction is associated with a decrease in sexual activity. These results provide clinicians and health educators a baseline of genital satisfaction to provide education and reassurance.

Concepts: Foreplay, Human penis size, Oral sex, Human sexuality, Penis, Sex organ, Human sexual behavior, Sexual intercourse

169

Sexual arousal is a motivational state that moves humans toward situations that inherently pose a risk of disease transmission. Disgust is an emotion that adaptively moves humans away from such situations. Incongruent is the fact that sexual activity is elementary to human fitness yet involves strong disgust elicitors. Using an experimental paradigm, we investigated how these two states interact. Women (final N=76) were assigned to one of four conditions: rate disgust stimuli then watch a pornographic clip; watch a pornographic clip then rate disgust stimuli; rate fear stimuli then watch a pornographic clip; or watch a pornographic clip then rate fear stimuli. Women’s genital sexual arousal was measured with vaginal photoplethysmography and their disgust and fear reactions were measured via self-report. We did not find that baseline disgust propensity predicted sexual arousal in women who were exposed to neutral stimuli before erotic content. In the Erotic-before-Disgust condition we did not find that sexual arousal straightforwardly predicted decreased image disgust ratings. However, we did find some evidence that sexual arousal increased self-reported disgust in women with high trait disgust and sexual arousal decreased self-reported disgust in women with low trait disgust. Women who were exposed to disgusting images before erotic content showed significantly less sexual arousal than women in the control condition or women exposed to fear-inducing images before erotic content. In the Disgust-before-Erotic condition the degree of self-reported disgust was negatively correlated with genital sexual arousal. Hence, in the conflict between the ultimate goals of reproduction and disease avoidance, cues of the presence of pathogens significantly reduce the motivation to engage in mating behaviors that, by their nature, entail a risk of pathogen transmission.

Concepts: Human behavior, Sexual arousal, Robert Plutchik, Erotica, Pathogen, Paul Ekman, Human sexuality, Sexual intercourse

164

trans-Epithelial delivery of medication across the vagina has proven successful for administration of small, lipophilic molecules such as sex steroids. However, little information is available regarding the vaginal delivery of larger and more polar molecules that currently require parenteral administration reflecting the bias that vaginal epithelium is a barrier to absorption of larger molecular weight (MW) molecules. Six healthy women underwent administration of 18 or 36mg of leuprolide, a GnRH agonist and a larger MW peptide, via a novel ethylene vinyl acetate (EVA) ring transvaginal drug delivery system (TVDS). Serum levels rose within 8h following insertion: low dose at 310pg/ml and high dose at 1220pg/ml, i.e. levels typically following parenteral injections of leuprolide. GnRHa biological activity was validated by secretion of gonadotropins and sex steroids. These results demonstrate that the non-keratinized vaginal epithelium permits a rapid absorption of a biologically active peptide and that there is significant potential for a novel TVDS to deliver peptides and possibly other macromolecules therapeutically.

Concepts: Pharmacology, Vagina, Human sexuality, Reproductive system, Peptide, Cervix, Molecule, Childbirth

142

In 2015, we conducted a cross-sectional, Internet-based, U.S. nationally representative probability survey of 2,021 adults (975 men, 1,046 women) focused on a broad range of sexual behaviors. Individuals invited to participate were from the GfK KnowledgePanel®. The survey was titled the 2015 Sexual Exploration in America Study and survey completion took about 12 to 15 minutes. The survey was confidential and the researchers never had access to respondents' identifiers. Respondents reported on demographic items, lifetime and recent sexual behaviors, and the appeal of 50+ sexual behaviors. Most (>80%) reported lifetime masturbation, vaginal sex, and oral sex. Lifetime anal sex was reported by 43% of men (insertive) and 37% of women (receptive). Common lifetime sexual behaviors included wearing sexy lingerie/underwear (75% women, 26% men), sending/receiving digital nude/semi-nude photos (54% women, 65% men), reading erotic stories (57% of participants), public sex (≥43%), role-playing (≥22%), tying/being tied up (≥20%), spanking (≥30%), and watching sexually explicit videos/DVDs (60% women, 82% men). Having engaged in threesomes (10% women, 18% men) and playful whipping (≥13%) were less common. Lifetime group sex, sex parties, taking a sexuality class/workshop, and going to BDSM parties were uncommon (each <8%). More Americans identified behaviors as "appealing" than had engaged in them. Romantic/affectionate behaviors were among those most commonly identified as appealing for both men and women. The appeal of particular behaviors was associated with greater odds that the individual had ever engaged in the behavior. This study contributes to our understanding of more diverse adult sexual behaviors than has previously been captured in U.S. nationally representative probability surveys. Implications for sexuality educators, clinicians, and individuals in the general population are discussed.

Concepts: Appeal, Chlamydia infection, Group sex, United States, Oral sex, Human sexual behavior, Human sexuality, Sexual intercourse

137

The Sexual Excitation Sexual/Inhibition Inventory for Women and Men (SESII-W/M) and the Sexual Excitation Scales/Sexual Inhibition Scales short form (SIS/SES-SF) are two self-report questionnaires for assessing sexual excitation (SE) and sexual inhibition (SI). According to the dual control model of sexual response, SE and SI differ between individuals and influence the occurrence of sexual arousal in given situations. Extreme levels of SE and SI are postulated to be associated with sexual difficulties or risky sexual behaviors. The present study was designed to assess the psychometric properties of the German versions of both questionnaires utilizing a large population-based sample of 2,708 participants (Mage = 51.19, SD = 14.03). Overall, psychometric evaluation of the two instruments yielded good convergent and discriminant validity and mediocre to good internal consistency. The original 30-item version of the SESII-W/M did not show a sufficient model fit. For a 24-item version of the SESII-W/M partial strong measurement invariance across gender, and strong measurement invariance across relationship status, age, and educational levels were established. The original structure (14 items, 3 factors) of the SIS/SES-SF was not replicated. However, a 4-factor model including 13 items showed a good model fit and strong measurement invariance across the before-mentioned participant groups. For both questionnaires, partial strong measurement invariance with the original American versions of the scales was found. As some factors showed unsatisfactory internal consistency and the factor structure of the original scales could not be replicated, scores on several SE- and SI-factors should be interpreted with caution. However, most analyses indicated sufficient psychometric quality of the German SESII-W/M and SIS/SES-SF and their use can be recommended in German-speaking samples. More research with diverse samples (i.e., different sexual orientations, individuals with sexual difficulties) is needed to ensure the replicability of the factor solutions presented in this study.

Concepts: Sexual attraction, Orgasm, Human sexuality, Factor analysis, Sexual intercourse, Sexual arousal, Sexual orientation, Psychometrics

119

Sexual assault on college campuses is a public health issue. However varying research methodologies (e.g., different sexual assault definitions, measures, assessment timeframes) and low response rates hamper efforts to define the scope of the problem. To illuminate the complexity of campus sexual assault, we collected survey data from a large population-based random sample of undergraduate students from Columbia University and Barnard College in New York City, using evidence based methods to maximize response rates and sample representativeness, and behaviorally specific measures of sexual assault to accurately capture victimization rates. This paper focuses on student experiences of different types of sexual assault victimization, as well as sociodemographic, social, and risk environment correlates. Descriptive statistics, chi-square tests, and logistic regression were used to estimate prevalences and test associations. Since college entry, 22% of students reported experiencing at least one incident of sexual assault (defined as sexualized touching, attempted penetration [oral, anal, vaginal, other], or completed penetration). Women and gender nonconforming students reported the highest rates (28% and 38%, respectively), although men also reported sexual assault (12.5%). Across types of assault and gender groups, incapacitation due to alcohol and drug use and/or other factors was the perpetration method reported most frequently (> 50%); physical force (particularly for completed penetration in women) and verbal coercion were also commonly reported. Factors associated with increased risk for sexual assault included non-heterosexual identity, difficulty paying for basic necessities, fraternity/sorority membership, participation in more casual sexual encounters (“hook ups”) vs. exclusive/monogamous or no sexual relationships, binge drinking, and experiencing sexual assault before college. High rates of re-victimization during college were reported across gender groups. Our study is consistent with prevalence findings previously reported. Variation in types of assault and methods of perpetration experienced across gender groups highlight the need to develop prevention strategies tailored to specific risk groups.

Concepts: Undergraduate education, Rape, New York City, Vagina, Bachelor's degree, Human sexuality, Human sexual behavior, Sexual intercourse