Physiological Evidence for a Mostly Heterosexual Orientation Among Men

A review of over 60 studies published from 1994 to 2012, covering 26 different samples from Australia, Canada, New Zealand, Norway, the United Kingdom, and the United States that included sufficient data for participants to be designated as mostly heterosexual (Kinsey 1s) concluded that such individuals showauniqueprofileof sexualandromanticcharacteristics that differentiate them as a distinctive sexual orientation (SavinWilliams & Vrangalova, in press). Mostly heterosexuals differed from two adjacent groups, exclusively heterosexuals and substantiallybisexuals, in reportingasmalldegreeofsame-sex sexual and/or romantic attraction, fantasies, and, occasionally, same-sex behavior. In addition, they constituted a substantial prevalence in the general population (the second most prevalent sexual orientation group, claimed by a mean of 7.6–9.5 % women and 3.6–4.1 % men), were relatively stable in their orientation over time, and felt that this sexuality was valid and meaningful to them. Onerecommendation fromthis reviewwas toassess whether a mostly heterosexual orientation is reflected in physiological sexual arousal—withspecificbenefitsaccrued if theanswerwas affirmative. Because all previous investigations of mostly heterosexuals have been based on self-report, an important question has not been addressed: Is a mostly heterosexualorientation basedonsubjective reportsof sexualandromanticattraction, fantasy, behavior, and identity manifested in physiological sexual responses? Given the general relationship between self-report andphysiologicalassessmentsofsexualorientation, it isexpected that the two would be congruent among most men. That is, unlike for many women, self-reported sexual orientation is usually strongly reflected in men’s sexual arousal (Bailey, 2009; Chivers, Seto, Lalumiere, Laan, & Grimbos, 2010). Reviewing physiological sexual arousal studies, we found that only a few includedmostly heterosexuals in their samples and none provided a separate analysis of this group. However, mostly heterosexual patterns of arousal were apparent among some heterosexual men. For example, one genital arousal study concluded that most men‘‘may possess a certain capacity for bisexual arousal’’ (Rieger, Chivers, & Bailey, 2005, p. 582); some heterosexual men showed an arousal pattern that can be interpreted as mostly heterosexual, with major arousal toward women and slight arousal toward men. Although an fMRI study scanned self-identified heterosexual and homosexual men, heterosexuals had‘‘exclusive or nearly exclusive sexual activity and feelings’’ for women (Safron et al., 2007, p. 23, emphasis added). A large majority of men show sexual arousal patterns consistentwith their self-reported sexualorientation (Bailey,2009). Thus, we expected that mostly heterosexual men would have considerable physiological sexual responses to females, similar to heterosexual men, and, in addition, some sexual response to males, more so than exclusively heterosexual men but less so than bisexual leaning heterosexual men. We had access to two previously published datasets from separate research programs that allowed us to test this congruence (for research design details, see Rieger & Savin-Williams, 2012; Rosenthal, Sylva, Safron, & Bailey, 2011, 2012). In thefirst study,dataassessing102men’spenile tumescence to erotic stimuli were collected with a focus on three groups: heterosexual, bisexual, and homosexual men (Rosenthal et al., 2011, 2012). This research included data on self-reported sexual attraction that allowed us to compare mostly heterosexuals to other men in their genital arousal patterns. R. C. Savin-Williams (&) G. Rieger Sex & Gender Lab, Department of Human Development, Cornell University, Ithaca, NY 14853, USA e-mail: savin-williams@cornell.edu