Women's genital sexual arousal to oral versus penetrative heterosexual sex varies with menstrual cycle phase at first exposure

The standardization of a new Explicit Pornographic Picture Set (EPPS)

Pictures with affective content have been extensively used in scientific studies of emotion and sexuality. However, only a few standardized picture sets have been developed that offer explicit images, with most lacking pornographic pictures depicting diverse sexual practices. This study aimed to fill this gap through developing a standardized affective set of diverse pornographic pictures (masturbation, oral sex, vaginal sex, anal sex, group sex, paraphilia) of same-sex and opposite-sex content, offering dimensional affective ratings of valence, arousal, and dominance, as well as co-elicited discrete emotions (disgust, moral and ethical acceptance). In total, 192 pornographic pictures acquired from online pornography platforms and 24 control IAPS images have been rated by 319 participants (Mage = 22.66, SDage = 4.66) with self-reported same- and opposite-sex sexual attraction. Stimuli were representative of the entire affective space, including positively and negatively perceived pictures. Participants showed differential affective perception of pornographic pictures according to gender and sexual attraction. Differences in affective ratings related to participants' gender and sexual attraction, as well as stimuli content (depicted sexual practices and sexes). From the stimuli set, researchers can select explicit pornographic pictures based on the obtained affective ratings and technical parameters (i.e., pixel size, luminosity, color space, contrast, chromatic complexity, spatial frequency, entropy). The stimuli set may be considered a valid tool of diverse explicit pornographic pictures covering the affective space, in particular, for women and men with same- and opposite-sex sexual attraction. This new explicit pornographic picture set (EPPS) is available to the scientific community for non-commercial use.

Determining menstrual cycle phase: An empirical examination of methodologies and recommendations for improvement in behavioral and brain sciences

The recent decade has brought an exciting proliferation of behavioral, psychological and neuroscientific research involving the menstrual cycle. However, the reliability and validity of many popular methodologies for determining menstrual cycle phase lack empirical examination. These under-investigated methods include: (1) predicting menstrual cycle phase using self-report information only (e.g., "count" methods), (2) utilizing ovarian hormone ranges to determine menstrual cycle phase, and (3) using ovarian hormone changes from limited measurements (e.g., two time points) to determine menstrual cycle phase. In the current study, we examine the accuracy of these methods for menstrual cycle phase determination using 35-day within-person assessments of circulating ovarian hormones from 96 females across the menstrual cycle. Findings indicate that all three common methods are error-prone, resulting in phases being incorrectly determined for many participants, with Cohen's kappa estimates ranging from -0.13 to 0.53 indicating disagreement to only moderate agreement depending on the comparison. Such methodological challenges are surmountable through careful study design, more frequent hormone assays (when possible), and utilization of sophisticated statistical methods. With increased methodological rigor in behavioral, psychological and neuroscientific research, the field will be poised to detect biobehavioral correlates of ovarian hormone fluctuations for the betterment of the mental health and wellbeing of millions of females.

Menstrual cycle-driven vs noncyclical daily changes in sexual desire

BACKGROUND

Past research on the association between sexual desire and the menstrual cycle has provided inconclusive results and has not considered the potential influence of psychological and physical changes that are frequently associated with the menstrual cycle.

AIM

To test the strength of association between the menstrual cycle (and associated symptoms) and changes in sexual desire.

METHODS

Prospective daily reports across 2 full menstrual cycles (2 months) from a sample of female university students (n = 213), were analysed. Analyses tested for average effects of the menstrual cycle on sexual desire, individual differences in these effects, and cyclical and noncyclical associations between sexual desire and the 9 menstrual cycle-related changes. Note that data presented in the current article come from a larger study from which other reports have been published.

OUTCOMES

Target variables were (1) daily change in sexual desire and (2) daily reports of 5 psychological changes and 4 physical changes that are commonly associated with the menstrual cycle.

RESULTS

Results showed that when considering average effects across participants, the menstrual cycle was associated with a small midcycle increase in sexual desire. However, multilevel analyses showed large individual differences in how the menstrual cycle influences sexual desire. Specifically, some participants showed a midcycle increase, others a perimenstrual increase, and others no change across the menstrual cycle. Moreover, results demonstrated that psychological changes were more important for predicting sexual desire as compared with physical changes.

CLINICAL IMPLICATIONS

These results suggest that daily measurement of sexual desire across multiple menstrual cycles may be an important tool in the assessment of sexual desire among some females.

STRENGTHS AND LIMITATIONS

Strengths of this study are the daily assessment of sexual desire and all symptoms for 2 menstrual cycles and multilevel analyses that allow the study of individual differences. Limitations include limited measurement of sexual desire based on only 2 questions and the lack of measures of relationship status and sexual orientation.

CONCLUSION

Emphasis is placed on the need to apply more rigorous research methods and to abandon simplistic average-effects models that are based on outdated theories and stereotypes.

Sexual attraction to visual sexual stimuli in association with steroid hormones across menstrual cycles and fertility treatment

BACKGROUND

Steroid hormones (i.e., estradiol, progesterone, and testosterone) are considered to play a crucial role in the regulation of women's sexual desire and sexual attraction to sexual stimuli throughout the menstrual cycle. However, the literature is inconsistent, and methodologically sound studies on the relationship between steroid hormones and women's sexual attraction are rare.

METHODS

This prospective longitudinal multisite study examined estradiol, progesterone, and testosterone serum levels in association with sexual attraction to visual sexual stimuli in naturally cycling women and in women undergoing fertility treatment (in vitro fertilization, IVF). Across ovarian stimulation of fertility treatment, estradiol reaches supraphysiological levels, while other ovarian hormones remain nearly stable. Ovarian stimulation hence offers a unique quasi-experimental model to study concentration-dependent effects of estradiol. Hormonal parameters and sexual attraction to visual sexual stimuli assessed with computerized visual analogue scales were collected at four time points per cycle, i.e., during the menstrual, preovulatory, mid-luteal, and premenstrual phases, across two consecutive menstrual cycles (n = 88 and n = 68 for the first and second cycle, respectively). Women undergoing fertility treatment (n = 44) were assessed twice, at the beginning and at the end of ovarian stimulation. Sexually explicit photographs served as visual sexual stimuli.

RESULTS

In naturally cycling women, sexual attraction to visual sexual stimuli did not vary consistently across two consecutive menstrual cycles. While in the first menstrual cycle sexual attraction to male bodies, couples kissing, and at intercourse varied significantly with a peak in the preovulatory phase, (all p ≤ 0.001), there was no significant variability across the second cycle. Univariable and multivariable models evaluating repeated cross-sectional relationships and intraindividual change scores revealed no consistent associations between estradiol, progesterone, and testosterone and sexual attraction to visual sexual stimuli throughout both menstrual cycles. Also, no significant association with any hormone was found when the data from both menstrual cycles were combined. In women undergoing ovarian stimulation of IVF, sexual attraction to visual sexual stimuli did not vary over time and was not associated with estradiol levels despite intraindividual changes in estradiol levels from 122.0 to 11,746.0 pmol/l with a mean (SD) of 3553.9 (2472.4) pmol/l.

CONCLUSIONS

These results imply that neither physiological levels of estradiol, progesterone, and testosterone in naturally cycling women nor supraphysiological levels of estradiol due to ovarian stimulation exert any relevant effect on women's sexual attraction to visual sexual stimuli.

Women's Estrus and Extended Sexuality: Reflections on Empirical Patterns and Fundamental Theoretical Issues

How do women's sexual interests change across their ovulatory cycles? This question is one of the most enduring within the human evolutionary behavioral sciences. Yet definitive, agreed-upon answers remain elusive. One empirical pattern appears to be robust: Women experience greater levels of sexual desire and interest when conceptive during their cycles. But this pattern is not straightforward or self-explanatory. We lay out multiple possible, broad explanations for it. Based on selectionist reasoning, we argue that the conditions that give rise to sexual interests during conceptive and non-conceptive phases are likely to differ. Because conceptive and non-conceptive sex have distinct functions, the sexual interests during conceptive and non-conceptive phases are likely to have different strategic ends. We discuss provisional evidence consistent with this perspective. But the exact nature of women's dual sexuality, if it exists, remains unclear. Additional empirical research is needed. But perhaps more crucially, this topic demands additional theory that fruitfully guides and interprets future empirical research.

Factors Influencing Sexual Vocalization in Human Females

Human females use numerous signals to attract male attention which can be ultimately motivated by enhanced paternal investment in the offspring. Sexual vocalization is a form of female sexual signaling. The majority of hypotheses attempting to explain the functional significance of vocalizations have been applied on non-human primates, while research on human females is scarce. This study investigated factors underlying sexual vocalization with a sample of 403 heterosexual Slovak females. Sexual vocalization was most frequent during penetration itself compared with other forms of sexual activities, which supports its signaling function. The most frequently reported sexual vocalizations were moaning/groaning, followed by screams and instructional commands, squeals, and words. Both the frequency and intensity of sexual vocalizations were significantly and positively associated with sexual arousal during the last sexual vaginal intercourse and sociosexuality. About 38% of females reported that they pretended vocalization and, in turn, pretended vocalization was exclusively associated with pretending orgasm. No direct evidence was found for any associations between self-reported frequency and intensity of sexual vocalization and partner satisfaction/physical attractiveness/ambition/dominance, self-perceived attractiveness, or occurrence of orgasm. The frequency (but not intensity) of sexual vocalization was positively influenced by the conception risk. On the proximate level, it seems that sexually less restricted females may use sexual vocalization to increase their sexual attractiveness to their current partner by means of boosting their partner's self-esteem. Enhanced vocalization by sexually unrestricted females may ultimately secure higher paternal investment and increase the confidence of the paternity of current sexual partner.

Probing Ovulatory-Cycle Shifts in Women’s Preferences for Men’s Behaviors

The existence of ovulatory-cycle shifts in women’s mate preferences has been a point of controversy. There is evidence that naturally cycling women in their fertile phase, compared with their luteal phase, evaluate specific behavioral cues in men as more attractive for sexual relationships. However, recent research has cast doubt on these findings. We addressed this debate in a large, preregistered, within-participants study using salivary-hormone measures and luteinizing-hormone tests. One hundred fifty-seven female participants rated the sexual and long-term attractiveness of 70 men in dyadic intersexual interactions in natural videos. Multilevel comparisons across two ovulatory cycles indicated that women’s mate preferences for men’s behaviors did not shift across the cycle for either competitive or courtship behavior. Within-women hormone levels and relationship status did not affect these results. Hormonal mechanisms and implications for estrus theories are discussed.

The aroma of arousal: Effects of menstrual cycle phase and women's sexual arousal state on men's responsiveness to women's body odor

Humans can detect aspects of identity, reproductive status, and emotional state from body odor. Women have shown a distinctive neural response to male sexually-aroused (vs. resting) sweat. The present study examined olfactory sexual arousal contagion in men. Axial sweat was collected from naturally cycling women when they were sexually aroused and when they were resting, during both their follicular and their luteal phase. Men were exposed to both aroused and resting sweat in a state of low-level sexual arousal. Participants smelling follicular phase sweat reported greater subjective sexual arousal and an increased likelihood to self-disclose than men smelling luteal phase sweat. They also showed increased genital arousal but this effect was moderated by the arousal state of the women; genital responding was greater in men smelling sexually aroused (vs. resting) sweat for those exposed to luteal (but not those exposed to follicular) phase body odor. Being able to detect the scent of sexual arousal could enhance perceiver arousal and provide information on whether to approach someone for sexual interaction.

Do women's preferences for masculine voices shift across the ovulatory cycle?

Are estrous mate preference shifts robust? This question is the subject of controversy within human evolutionary sciences. For nearly two decades, mate preference shifts across the ovulatory cycle were considered an important feature of human sexual selection, directing women's attention toward mates with indicators of "good genes" in their fertile phase, when conception is possible. However, several recent studies on masculine faces, bodies and behaviors did not find evidence supporting this account, known as the good genes ovulatory shift hypothesis. Furthermore, evidence that preferences for masculine characteristics in men's voices are related to women's cycle phase and hormonal status is still equivocal. Here, we report two independent within-subject studies from different labs with large sample sizes (N = 202 tested twice in Study 1; N = 157 tested four times in Study 2) investigating cycle shifts in women's preferences for masculine voices. In both studies, hormonal status was assessed directly using salivary assays of steroid hormones. We did not find evidence for effects of cycle phase, conception risk, or steroid hormone levels on women's preferences for masculine voices. Rather, our studies partially provide evidence for cycle shifts in women's general attraction to men's voices regardless of masculine characteristics. Women's relationship status and self-reported stress did not moderate these findings, and the hormonal pattern that influences these shifts remains somewhat unclear. We consider how future work can clarify the mechanisms underlying psychological changes across the ovulatory cycle.

Menstrual cycle phase predicts women's hormonal responses to sexual stimuli

A robust body of research has demonstrated shifts in women's sexual desire and arousal across the menstrual cycle, with heightened desire and arousal coincident with heightened probability of conception (POC), and it is likely that ovarian hormones modulate these shifts. However, studies in which women are exposed to audiovisual sexual stimuli (AVSS) at high POC (mid-follicular) and low POC (luteal) phases have failed to detect significant differences in genital or subjective arousal patterns based on menstrual cycle phase. Here, we tested whether hormonal responsivity to AVSS differs as a function of cycle phase at testing, and whether phase during which participants were first exposed to AVSS influences hormonal responsivity in subsequent test sessions. Twenty-two naturally cycling heterosexual women were exposed to AVSS during the follicular and luteal phases, with phase at first test session counterbalanced across participants. Salivary samples were collected before and after AVSS exposure. Estradiol increased significantly during both follicular and luteal phase sessions, and increases were higher during the follicular phase. Testosterone (T) increased significantly only during the follicular phase session, while progesterone (P) did not change significantly during either cycle phase. Session order and current cycle phase interacted to predict P and T responses, such that P and T increased during the follicular phase in women who were first tested during the luteal phase. These data suggest that menstrual cycle phase influences hormonal responsivity to AVSS, and contribute to a growing body of clinical and empirical literature on the neuroendocrine modulators of women's sexuality.

The Specificity of Women's Sexual Response and Its Relationship with Sexual Orientations: A Review and Ten Hypotheses

Category-specific sexual response describes a pattern wherein the individual shows significantly greater responses to preferred versus nonpreferred categories of sexual stimuli; this pattern is described as gender specific for sexual orientation to gender, or gender nonspecific if lacking response differentiation by gender cues. Research on the gender specificity of women's sexual response has consistently produced sexual orientation effects, such that androphilic women (sexually attracted to adult males) typically show gender-nonspecific patterns of genital response and gynephilic women (sexually attracted to adult females) show more gender-specific responses. As research on the category specificity of sexual response has grown, this pattern has also been observed for other measures of sexual response. In this review, I use the Incentive Motivation and Information Processing Models as complementary frameworks to organize the empirical literature examining the gender specificity of women's sexual response at each stage of sexual stimulus processing and response. Collectively, these data disconfirm models of sexual orientation that equate androphilic women's sexual attractions with their sexual responses to sexual stimuli. I then discuss 10 hypotheses that might explain variability in the specificity of sexual response among androphilic and gynephilic women, and conclude with recommendations for future research on the (non)specificity of sexual response.

Gender-Specificity in Viewing Time Among Heterosexual Women

Measures of sexual interest tend to be more gender-specific in heterosexual men than in heterosexual women. Cognitive measures, such as viewing time to attractive stimuli, may also show similar patterns of gender-specificity or nonspecificity among men and women and thus serve as useful adjuncts to more direct measures of sexual interest. The objectives of the present research were to determine the extent of gender-specificity in women's viewing times for female pictures (varying in their perceived physical attractiveness) and explore the influence of social comparison of physical appearance on these patterns of responses. In Study 1, we recorded only women's viewing times for pictures of both genders, measured self-reported menstrual cycle phase, and manipulated the waist-to-hip ratio of the women in the female pictures. In Study 2, we recorded women's and men's viewing times, self-reported sexual attraction to pictures of males and females, and physical appearance social comparison. Study 1 found that heterosexual women's viewing time toward female pictures was not associated with manipulation of the perceived attractiveness of those pictures. Study 2 found that heterosexual men were more gender-specific than heterosexual women in their viewing time patterns. We also found that reported sexual attraction and physical appearance social comparison were associated with heterosexual women's viewing times for female pictures, while heterosexual men's viewing times were associated with sexual attraction only. Our results are discussed in relation to the utility of viewing time as an indicator of visual attention toward attractive or sexually appealing visual stimuli.

Comparing Subjective Ratings of Sexual Arousal and Desire in Partnered Sexual Activities from Women of Different Sexual Orientations

Little is known about non-monosexual women's sexual arousal and desire. Typically, bisexual women have been excluded from research on sexual arousal and desire, whereas mostly heterosexual and mostly lesbian women have been placed into monosexual categories. This research (1) compared the subjective sexual arousal and desire of self-identified heterosexual, mostly heterosexual, bisexual, mostly lesbian, and lesbian women in partnered sexual activities with men and with women, and (2) compared within-group differences for subjective sexual arousal and desire with men versus women for the five groups. Participants included 388 women (M age = 24.40, SD = 6.40, 188 heterosexual, 53 mostly heterosexual, 64 bisexual, 32 mostly lesbian, 51 lesbian) who filled out the Sexual Arousal and Desire Inventory (SADI). Sexual orientation was associated with sexual arousal and desire in sexual activities with both men and with women. Bisexuals reported higher sexual arousal and desire for women than heterosexuals and lesbians, while lesbians reported lower sexual arousal and desire with men than the other groups. Heterosexuals and mostly heterosexuals scored higher on the male than on the female motivational dimension of the SADI, while the reverse was found for lesbians and mostly lesbians. Findings indicate that non-monosexuals have higher sexual arousal and desire in sexual activities with women than monosexuals. Further, bisexual women did not differentiate their sexual arousal with men versus women, while the other sexual orientation groups differentiated in terms of their motivation to engage in sexual activity. These findings may have implications for how female sexual orientation is conceptualized.

Duration of oral contraceptive use predicts women's initial and subsequent subjective responses to sexual stimuli

Recent work suggests that a woman's hormonal state when first exposed to visual sexual stimuli (VSS) modulates her initial and subsequent responses to VSS. The present study investigated whether women's initial hormonal state was related to their subjective ratings of VSS, and whether this relationship differed with VSS content. We reanalyzed previously collected data from 14 naturally cycling (NC) women and 14 women taking oral contraceptives (OCs), who subjectively rated VSS at three hormonal time-points. NC women's ratings of 216 unique sexual images were collected during the menstrual, periovulatory, and luteal phases of their menstrual cycles, and OC women's ratings were collected at comparable time-points across their pill-cycles. NC women's initial hormonal state was not related to their ratings of VSS. OC women's initial hormonal state predicted their ratings of VSS with minimal contextual information and of images depicting female-to-male oral sex. Specifically, women who entered the study in the third week of their pill-cycle (OC-3 women) rated such images as less attractive at all testing sessions than did all other women. OC-3 women were also the only women to rate decontextualized VSS as unattractive at all testing sessions. These results corroborate previous studies in which women's initial hormonal state was found to predict subsequent interest in sexual stimuli. Future work, with larger samples, should more directly investigate whether OC-3 women's negative assessment of specific types of VSS reflects a reaction to the laboratory environment or a broader mechanism, wherein OC women's sexual interests decrease late in their pill-cycle.