A brief review and discussion of sex differences in the specificity of sexual arousal

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

Reproductive-aged women show increased interest in sexual activity during the fertile phase of the menstrual cycle that can motivate sexual behavior and thereby increase the likelihood of conception. We examined whether women demonstrated greater sexual responses (subjective and genital sexual arousal) to penetrative versus oral sexual activities during the fertile versus non-fertile phases of their cycles, and whether women's arousal responses were influenced by the phase during which they were first exposed to these sexual stimuli (e.g., Slob et al., 1991; Wallen and Rupp, 2010). Twenty-two androphilic women completed two identical sexual arousal assessments in which genital responses were measured with a vaginal photoplethysmograph and their feelings of sexual arousal were recorded. Women viewed an array of 90s films varying by couple type (female-female, male-male, female-male) and sexual activity type (oral or penetrative), during the fertile (follicular) and non-fertile (luteal) phases of their menstrual cycle, with the order of cycle phase at the first testing session counter-balanced. Women tested first in the fertile phase showed significantly greater genital arousal to female-male penetrative versus oral sex in both testing sessions, whereas self-reports of sexual arousal were not affected by cycle phase or testing order. These results contribute to a growing body of research suggesting that fertility status at first exposure to sexual stimuli has a significant effect on subsequent sexual responses to sexual stimuli, and that this effect may differ for subjective versus genital sexual arousal.

Implicit sexual associations in heterosexual and homosexual women and men

Patterns of genital arousal to sexual stimuli are somewhat different between men and women. Heterosexual males and homosexual males show clear category specific arousal that is consistent with their self-reported sexual preference. However, heterosexual women do not show this category specificity. In the present study, we attempted to measure a person's automatic appraisals of stimuli with respect to the concept of sex via the use of implicit measures (the Implicit Association Test and the priming task). In three experiments, we showed that heterosexual females did not show a sex-related category specific response in favor of male versus female stimuli. However, this lack of specificity was not due to a lack of sex-related appraisals, but by equal appraisals of both male and female stimuli. On the other hand, heterosexual men, homosexual men, and homosexual women all showed automatic sex-related appraisals of stimuli that were category specific and in line with their self-reported sexual preference. The study shows difference in the pattern of sexual interest between genders at the earliest stages of the evaluation of a stimulus.

Men and women with bisexual identities show bisexual patterns of sexual attraction to male and female "swimsuit models"

Do self-identified bisexual men and women actually show bisexual patterns of sexual attraction and interest? To answer this question, I studied bisexual men's and women's sexual attraction to photographed male and female "swimsuit models" that varied in attractiveness. Participants (663 college students and gay pride attendees, including 14 self-identified bisexual men and 17 self-identified bisexual women) rated their degree of sexual attraction to 34 male and 34 female swimsuit models. Participants' viewing times to models were unobtrusively assessed. Results showed that bisexual men and women showed bisexual patterns of attraction and viewing times to photo models, which strongly distinguished them from same-sex heterosexual and homosexual participants. In contrast to other groups, which showed evidence of greater male than female category specificity, bisexual men and women did not differ in category specificity. Results suggest that there are subsets of men and women who display truly bisexual patterns of sexual attraction and interest.

Effects of sex and sexual orientation on self-reported attraction and viewing times to images of men and women: testing for category specificity

In a paradigm that asked participants to rate the sexual attractiveness of male and female swimsuit models, Lippa, Patterson, and Marelich (2010) showed that heterosexual men's category specificity exceeded heterosexual women's in two ways: (1) Heterosexual men showed much larger differences in their attraction and viewing times to male versus female photo models than heterosexual women, and (2) heterosexual men's attractions to female but not male models increased with model attractiveness whereas heterosexual women's attractions to both sexes increased with model attractiveness. The current study used the same paradigm to study category specificity in homosexual and heterosexual participants. In addition to replicating previous findings for heterosexual men and women, the results showed that homosexual men were high on category specificity, like heterosexual men, whereas lesbians showed lower levels of category specificity than men, but sometimes higher levels than heterosexual women.

Prepared for Anything?

Men’s genital arousal occurs in response to a limited number of sexual stimuli, whereas women’s genital arousal occurs in response to a wide range of sexual stimuli, including those depicting nonpreferred cues. Researchers have hypothesized that women’s nonspecific pattern of genital arousal prepares the body for sexual activity, thus functioning to protect the genital organs against injury. If this hypothesis is correct, women should show genital responses to any cues suggesting sexual activity, even unappealing cues that involve nonconsensual sex and extreme violence. Fifteen men and 15 women listened to fourteen 2-min audiotaped narratives that depicted an interaction between a man and a woman and that varied factorially according to the presence of consent, violence, and sexual activity. The results support the preparation hypothesis: Men showed the greatest genital arousal in response to narratives depicting consensual, nonviolent sex, whereas women showed similar responses to all the narratives involving sexual activities, including those describing a sexual assault.

Subliminal sexual stimuli facilitate genital response in women

Visual sexual stimuli (VSS) are believed to undergo an automatic process of stimulus appraisal and (genital or subjective) response generation. Consistent with this belief, studies have found that subliminal VSS can facilitate responses to subsequent sexual stimulus presentations. We tested whether subliminal sexual stimuli facilitated a genital response in women and, furthermore, whether this genital response could be modulated by both opposite-sex stimuli and same-sex stimuli (i.e., whether the genital response to subliminal stimuli is category-specific or nonspecific). Twenty heterosexual women underwent vaginal photoplethysmography while being subliminally (20 ms) exposed to same-sex, opposite-sex, and nonsexual slides in a priming experiment. Vaginal pulse amplitude was increased when target stimuli were preceded by both opposite-sex and same-sex priming stimuli relative to nonsexual priming stimuli. This finding suggests that subliminal VSS were subjected to automatic stimulus processing, thereby facilitating nonspecific genital response preparation. Results are discussed in terms of implicit and explicit memory access and the evolutionary benefit of female nonspecific genital response.

What is queer about sex?: expanding sexual frames in theory and practice

Psychotherapists often believe if couples improve their communication and emotional dynamics, good sex follows. In practice we often find otherwise and have many questions about how to proceed to work with sexuality issues more directly. This paper presents the many challenges working with sex including the following: the fluidity and multidimensionality of sex and gender, the incongruities and paradoxes in sexual behavior, thoughts, attractions, feelings, and sensations, and the powerful feelings, impasses, surprises, and confusion therapists often experience doing the work. In essence, what is queer about sex? Using the couple as client, expansive ways of thinking and working with sexuality are presented including the development of inclusive models of sex, gender, and sexual response, as well as new approaches to standard sex therapy techniques such as sexual history-taking, redefining sex, and sensate focus. Techniques are presented with an emphasis on the therapist's use of self as sexual change agent including integrating multiple theoretical perspectives (psychodynamic, systemic, and cognitive-behavioral), co-creating a safe treatment frame, and how to intervene within the cognitive, affective, behavioral, somatic, and discursive realms.

Category-specificity in sexual interest in gay men and lesbians

The present study assessed the category-specificity of sexual interest of gay men and lesbians toward an understanding of the possible interaction of sex and sexual orientation that may exist in this phenomenon. Utilizing viewing time as a measure of sexual interest, we had participants (N = 99) rate the sexual appeal of sexually provocative pictures while the amount of time spent viewing each picture was inconspicuously measured. As hypothesized, same-sex oriented individuals demonstrated a category-specific pattern of sexual interest. That is, gay men and lesbians (1) viewed preferred sex pictures (i.e., of same sex) significantly longer than nonpreferred sex pictures (i.e., of opposite sex) and (2) rated preferred sex pictures as significantly more sexually appealing than nonpreferred sex pictures. Additionally, the difference in viewing times between preferred and nonpreferred sexual stimuli was not significantly different for gay men and lesbians, suggesting that lesbians are as category-specific as gay men. The implications of these findings are discussed.

An evaluation of the validity of thermography as a physiological measure of sexual arousal in a non-university adult sample

Thermography is a promising technology for the physiological measurement of sexual arousal in both men and women. This study was designed to extend our previous college student thermography study findings to an older sample (M age = 37.05 years), add an anxiety control group to further examine the specificity of temperature change, and examine the relationship between genital temperature and a continuous measure of subjective sexual arousal. Healthy men (n = 40) and women (n = 39) viewed a neutral film clip after which they were randomly assigned to view one of four other videos: neutral (n = 20), humor (n = 19), anxiety provoking (n = 20) or sexually explicit (n = 20). Genital and thigh temperature were continuously recorded using a TSA ImagIR thermographic camera. Continuous and discrete reports of subjective sexual arousal were also obtained. Results supported the validity of thermography as a measure of sexual arousal: temperature change was specific to the genitals during the sexual arousal condition and was significantly correlated with subjective continuous and discrete reports of sexual arousal. Further development should assess the potential of thermography as a tool for the diagnosis and treatment evaluation of sexual arousal difficulties and for studying sex differences.

Women's sexual responses to heterosexual and lesbian erotica: the role of stimulus intensity, affective reaction, and sexual history

Past research has demonstrated that women do not show a "category-specific" genital response to erotic stimuli. That is, on average, heterosexual and lesbian women are indistinguishable in terms of their physiological genital responses to heterosexual versus lesbian erotica. In two studies with heterosexual women (n = 28 for Study 1; n = 30 for Study 2) and lesbians (n = 24 for Study 1; n = 25 for Study 2), results confirmed that, on average, women did not show category-specific genital responses or category-specific subjective sexual arousal. However, there was evidence of notable within-group variability; many women did respond to the stimuli in a category-specific manner. Heterosexual women were more likely than lesbian women to demonstrate category-specificity. Findings also revealed that category-specificity was associated with multiple factors, including affective responses to the erotic stimuli and sexual history. Results of this study highlight the complexity of women's sexual identities and sexual responses.

Looking at and Longing for Male and Female “Swimsuit Models”

Men’s sexual attractions tend to be more category specific than women’s—that is, men tend to be attracted to either women or men, whereas women are more likely to show some degree of attraction to both sexes. To explore this phenomenon further, the authors assessed 62 heterosexual men and 79 heterosexual women on their time spent viewing and self-reported sexual attraction to photographed male and female “swimsuit models” who varied in attractiveness. Consistent with theoretical predictions, men showed stronger category specificity than women. Specifically, men were more sexually attracted to female than male models and men spent more time viewing female than male models, particularly when models were highly attractive. In contrast, women were sexually attracted to both female and male models—with sexual attraction to both sexes increasing with models’ attractiveness—and women’s viewing time was better predicted by model attractiveness than by model sex.

Elucidating women's (hetero)sexual desire: definitional challenges and content expansion

The literature on women's sexual desire is reviewed with an emphasis on definitional challenges, an assessment of the empirical basis for the distinction between spontaneous and responsive desire, a reconsideration of the extent to which women's sexual desire is relational in nature, and an exploration of the incentive value of sex for women as a factor partially independent from the experience of sexual desire. Nine recommendations are made regarding research and diagnostic directions. The article concludes with an appeal for the inclusion of eroticism in research and clinical work on sexual desire.

Agreement of self-reported and genital measures of sexual arousal in men and women: a meta-analysis

The assessment of sexual arousal in men and women informs theoretical studies of human sexuality and provides a method to assess and evaluate the treatment of sexual dysfunctions and paraphilias. Understanding measures of arousal is, therefore, paramount to further theoretical and practical advances in the study of human sexuality. In this meta-analysis, we review research to quantify the extent of agreement between self-reported and genital measures of sexual arousal, to determine if there is a gender difference in this agreement, and to identify theoretical and methodological moderators of subjective-genital agreement. We identified 132 peer- or academically-reviewed laboratory studies published between 1969 and 2007 reporting a correlation between self-reported and genital measures of sexual arousal, with total sample sizes of 2,505 women and 1,918 men. There was a statistically significant gender difference in the agreement between self-reported and genital measures, with men (r = .66) showing a greater degree of agreement than women (r = .26). Two methodological moderators of the gender difference in subjective-genital agreement were identified: stimulus variability and timing of the assessment of self-reported sexual arousal. The results have implications for assessment of sexual arousal, the nature of gender differences in sexual arousal, and models of sexual response.

Phosphodiesterase type 5 inhibitors and female sexual response: faulty protocols or paradigms?

INTRODUCTION

Phosphodiesterase type 5 inhibitors (PDE5), such as sildenafil, tadalafil, and vardenafil, have revolutionized the treatment of erectile dysfunction. Few successes, in contrast, have been reported for the use of these agents in treatment of sexual arousal problems in women.

AIM

To review research examining efficacy of PDE5 in women, critique the methods and models employed, and integrate the findings within a broader, gender-specific understanding of female sexual response.

METHODS

A conceptual and methodological review of all published studies examining PDE5 efficacy in female samples.

MAIN OUTCOME MEASURES

Study methods, populations, outcome measures, study results.

RESULTS

A total of 16 studies were reviewed. Studies using self-reported measures of sexual functioning showed mixed results whereas studies examining physiological effects of PDE5 on genital vasocongestion consistently report significant effects on genital sexual response.

CONCLUSIONS

The lack of efficacy of PDE5 treatment in women is likely attributable to gender differences in the concordance between physiological and psychological components of sexual response. Discordance between genital and subjective measures of sexual response in women may be augmented by PDE5 effects on genital vasocongestion in some populations, rendering successful treatment unlikely via pharmacological treatment alone.

Sex differences in patterns of genital sexual arousal: measurement artifacts or true phenomena?

Sex differences in patterns of sexual arousal have been reported recently. Men's genital arousal is typically more category-specific than women's, such that men experience their greatest genital arousal to stimuli depicting their preferred sex partners whereas women experience significant genital arousal to stimuli depicting both their preferred and non-preferred sex partners. In addition, men's genital and subjective sexual arousal patterns are more concordant than women's: The correlation between genital and subjective sexual arousal is much larger in men than in women. These sex differences could be due to low response-specificity in the measurement of genital arousal in women. The most commonly used measure of female sexual arousal, vaginal photoplethysmography, has not been fully validated and may not measure sexual arousal specifically. A total of 20 men and 20 women were presented with various sexual and non-sexual emotionally laden short film clips while their genital and subjective sexual arousal were measured. Results suggest that vaginal photoplethysmography is a measure of sexual arousal exclusively. Women's genital responses were highest during sexual stimuli and absent during all non-sexual stimuli. Sex differences in degree of category-specificity and concordance were replicated: Men's genital responses were more category-specific than women's and men's genital and subjective sexual arousal were more strongly correlated than women's. The results from the current study support the continued use of vaginal photoplethysmography in investigating sex differences in patterns of sexual arousal.

Sexual pleasure and motivation

Individuals engage in behaviors or partake of specific substances because it pleases them. Indeed, without the sensations of pleasure and displeasure we would be unlikely to repeat or restrict behaviors. Since repetitive sexual activity over the millennia has ensured the continuance of the human race, it is perhaps surprising that pleasure has received little attention in the research literature on sexual function and behavior. By exploring sexual pleasure and motivation theories and studies relevant to the evaluation of sexual function and dysfunction, a goal response model is presented. This model proposes a route from sexual stimuli, via cognitive and emotional processing to behavior and subsequent feedback, which illustrates how eudemonic goals could influence treatment outcomes.

Sex differences in visual attention to erotic and non-erotic stimuli

It has been suggested that sex differences in the processing of erotic material (e.g., memory, genital arousal, brain activation patterns) may also be reflected by differential attention to visual cues in erotic material. To test this hypothesis, we presented 20 heterosexual men and 20 heterosexual women with erotic and non-erotic images of heterosexual couples and tracked their eye movements during scene presentation. Results supported previous findings that erotic and non-erotic information was visually processed in a different manner by both men and women. Men looked at opposite sex figures significantly longer than did women, and women looked at same sex figures significantly longer than did men. Within-sex analyses suggested that men had a strong visual attention preference for opposite sex figures as compared to same sex figures, whereas women appeared to disperse their attention evenly between opposite and same sex figures. These differences, however, were not limited to erotic images but evidenced in non-erotic images as well. No significant sex differences were found for attention to the contextual region of the scenes. Results were interpreted as potentially supportive of recent studies showing a greater non-specificity of sexual arousal in women. This interpretation assumes there is an erotic valence to images of the sex to which one orients, even when the image is not explicitly erotic. It also assumes a relationship between visual attention and erotic valence.

Through evolution's eyes: extracting mate preferences by linking visual attention to adaptive design

Information is crucial to decision-making, including mate choice decisions. Perceptual systems, such as attention, evolved in part to forage for reproductive information; consequently, these systems can be used to reveal mate preferences. Here, I consider the place of visual information in human mate choice and provide a rationale for pressing into service methods drawn from the attention literature for the study of mate choice decisions. Because visual attention is allocated automatically and selectively, it may be used to complement common methods of mate preference assessment, such as self-report questionnaires and measures of genital arousal, while avoiding some of the pitfalls of these methods. Beyond the utility of increasing confidence in extant research findings by employing relatively unobtrusive methods, visual attention paradigms can also allow researchers to explore a variety of questions that are rarely asked, such as those concerned with signal efficiency and tradeoffs in the assessment of mate value.

Correlates of early overt and covert sexual behaviors in heterosexual women

We used data provided by 417 Kinsey-0 and Kinsey-1 heterosexual women using an anonymous computerized survey to determine the adult correlates of two female-female behaviors that occurred before age 18; 25.4% of participants reported engaging in one or both behaviors. Sexual experimentation with females and masturbating using images of females before age 18 were statistically significant predictors of four different female-female behaviors in adulthood: sexual contact with females, masturbating using images of females, preferring a female fantasy partner while having sex with a favorite (male) partner, and voyeurism directed at females; 27.3% of the participants reported engaging in one or more of the latter four behaviors. The analogous early female-male behaviors were not statistically significant predictors of female-female behaviors in adults. Conditioning resulting from participation in these early female-female behaviors might explain the correlations between the two early behaviors and the subsequent four adult same-gender behaviors. The earliest and latest ages that participants engaged in each early behavior and case-by-case analysis showed that the sequence of events leading to the female-female adult behaviors was initial sexual experimentation with similar age females (at a median age of 9 years) followed by masturbating using images of females (at a median age of 15). These results suggest that conditioning and other forms of learning play an important role in establishing coexisting same-gender orientations in heterosexual women.

ORIGINAL RESEARCH—PHYSIOLOGY: Thermography as a Physiological Measure of Sexual Arousal in Both Men and Women

INTRODUCTION

Current physiological measures of sexual arousal are intrusive, hard to compare between genders, and quantitatively problematic.

AIM

To investigate thermal imaging technology as a means of solving these problems.

METHODS

Twenty-eight healthy men and 30 healthy women viewed a neutral film clip, after which they were randomly assigned to view one of three other video conditions: (i) neutral (N = 19); (ii) humor (N = 19); and (iii) sexually explicit (N = 20).

MAIN OUTCOME MEASURES

Genital and thigh temperatures were continuously recorded using a TSA ImagIR camera. Subjective measures of sexual arousal, humor, and relaxation were assessed using Likert-style questions prior to showing the baseline video and following each film.

RESULTS

Statistical (Tukey HSD) post-hoc comparisons (P < 0.05) demonstrated that both men and women viewing the sexually arousing video had significantly greater genital temperature (mean = 33.89 degrees C, SD = 1.00) than those in the humor (mean = 32.09 degrees C, SD = 0.93) or neutral (mean = 32.13 degrees C, SD = 1.24) conditions. Men and women in the erotic condition did not differ from each other in time to peak genital temperature (men mean = 664.6 seconds, SD = 164.99; women mean = 743 seconds, SD = 137.87). Furthermore, genital temperature was significantly and highly correlated with subjective ratings of sexual arousal (range r = 0.51-0.68, P < 0.001). There were no significant differences in thigh temperature between groups.

CONCLUSION

Thermal imaging is a promising technology for the assessment of physiological sexual arousal in both men and women.