So I finally get back from my blissful but mosquito-ridden week of internet-free camping to find another big flame war going on in the asexuality tag. I guess it started with amazingatheist’s demand for the scientific study of asexuals and arousal?
Well, guess what guys. It’s already been done. And get this - instead of proving that we don’t exist, it actually serves to validate asexuality as an orientation and not a disorder.
Physiological and Subjective Sexual Arousal in Self-Identified Asexual Women (-Lori A. Brotto and Morag A. Yule))
Abstract (emphasis added by me)
Asexuality can be defined as a lifelong lack of sexual attraction. Empirical research on asexuality reveals significantly lower self-reported sexual desire and arousal and lower rates of sexual activity;however, the speculation that there may also be an impaired psychophysiological sexual arousal response has never been tested. The aim of this study was to compare genital (vaginal pulse amplitude; VPA) and subjective sexual arousal in asexual and non-asexual women. Thirty-eight women between the ages of 19 and 55 years (10 heterosexual, 10 bisexual, 11 homosexual, and 7 asexual) viewed neutral and erotic audiovisual stimuli while VPA and self-reported sexual arousal and affect were measured. There were no significant group differences in the increased VPA and self-reported sexual arousal response to the erotic film between the groups. Asexuals showed significantly less positive affect, sensuality-sexual attraction, and self-reported autonomic arousal to the erotic film compared to the other groups;however, there were no group differences in negative affect or anxiety. Genital-subjective sexual arousal concordance was significantly positive for the asexual women and non-significant for the other three groups, suggesting higher levels of interoceptive awareness among asexuals.Taken together, the findings suggest normal subjective and physiological sexual arousal capacity in asexual women and challenge the view that asexuality should be characterized as a sexual dysfunction.
From the study itself (emphasis mine):
The study of vaginal photoplethysmography has led to some important advances in our understanding of women’s sexual response….. lesbian and heterosexual women showed the same degree of increase in vaginal pulse amplitude (VPA; the more sensitive and specific index in vaginal photoplethysmography), regardless of their stated sexual orientation and irrespective of the stimuli shown—whether heterosexual, homosexual, or non-human primate (Chivers, Rieger, Latty, & Bailey, 2004; Chivers, Seto, & Blanchard, 2007). If such ‘‘target non-specificity’’ was a feature of all women, including asexuals, then one might predict that asexual women would show a similar degree of genital response to stimuli compared to heterosexual and lesbian women despite their stated preference for no sexual partners.
so really, photoplethysmography (a fancy name for detecting blood flow and thus physical arousal) isn’t very useful as measure of orientation, at least in women. And this kind of pokes a hole in the whole argument that responses to porn invalidate asexuality, since it is clear that genital arousal in response to pornographic material doesn’t correlate to actual orientation. Also, it’s important to note that physical arousal by itself is only one part of the complex response that is sexual attraction - there are also complex mental/neurological components.
And the Summary of Findings (emphasis added by me):
Summary of Findings
Overall, the findings revealed no significant differences between asexual women and heterosexual, homosexual, or bisexual women in the genital arousal response to a heterosexual audio-visual erotic stimulus in a controlled, laboratory environment. Instead, all women showed a significant increase in response to the erotic film. A main effect of Film was also found for subjective sexual arousal in that all groups showed a significant increase, with no significant group differences. On perceived genital arousal, there was a trend towards a Group x Film interaction such that there was less of an increase among the asexuals compared to the other groups; however, this did not reach statistical significance. Given the small effect size, this effect might not be magnified with a larger sample. As predicted, there was a significant Group x Film interaction on the sensuality-sexual attraction domain of the Film Scale such that there was a significant increase following the erotic film in all groups except the asexual women.
On other self-report measures of affect, there was a significant Group x Film interaction for positive affect to the erotic stimulus such that asexuals did not show the increase in positive affect with the erotic stimulus seen by the other groups. There were no main effects of group or film on negative affect, and anxiety decreased by a similar magnitude for all women with exposure to the erotic stimulus. Interestingly, there was a significant Group x Film interaction for autonomic arousal in that all women showed a significant increase with the erotic film except the asexuals.
Taken together, these findings suggest that desire for sexual activity with another individual is significantly lower in asexual women compared to other sexual orientation groups; however, desire for solitary sexual activity was the same in asexual women compared to sexual women….
and finally, the conclusion:
Overall, we found a significant psychophysiological sexual response in the laboratory among asexual women that did not differ from responses seen in groups of heterosexual, bisexual, and homosexual women. Moreover, subjective sexual response did not differ between the groups, but self-reported sensuality-sexual attraction in response to the erotic film was significantly lower among the asexual women, as expected.
Interestingly, concordance between genital and subjective sexual arousal was significantly positive for asexual women, and non-significant for the other groups of women, suggesting greater interoceptive awareness of genital excitement in asexual women.
The findings have implications for our conceptualization of asexuality and suggest that, contrary to recent media speculations, asexuality may not be a sexual dysfunction given that arousability pathways appear intact (insofar as our measures test them). Moreover, because the proposed DSM-5 criteria for Sexual Interest/Arousal Disorder require the presence of dis- tress or impairment (Brotto, 2010; Graham, 2010), asexuality would not fall under this definition given asexuals’ lack of distress. The clinical implication of this conclusion means that the asexual woman who is prompted to seek sex therapy at the insistence of a distressed (sexual) partner should not be the recipient of taught sexual skills to boost sexual desire nor should she be a target for pharmacological and/or hormonal intervention to boost desire. Rather, the (sexual/asexual) couple might be the focus of relationship therapy aimed at how to negotiate her lack of sexual attraction and what agreements can be reached about sexual activity that sufficiently appease both partners (e.g., agreeing that sexual activity may take place consensually but without interest for it on her part).
Taken together, these results add to the small but growing literature on asexuality. What remains to be studied are whether there are neural correlates to the lack of sexual attraction, whether there are other (non-sexual) biological indicators pointing to asexuality being a sexual orientation (e.g., digit ratio measurement), and further understanding the mecha- nisms by which romantic and sexual aspects of attraction may become de-coupled. The scientific study of asexuality might also be advanced by systematic comparisons of asexuality (which is lifelong) versus acquired HSDD in order to understand how these populations might be distinct.