Asexuality, the state of having no sexual attraction for either sex, has been studied only sparingly. Related issues are sexual aversion disorder and hypoactive sexual desire disorder (HSDD), which have been studied more frequently in recent years (e.g., Beck, 1995; Rosen & Leiblum, 1995). In both sexual aversion disorder and HSDD, there usually is or was a sexual orientation toward partners of either or both genders, but there is either an aversion for genital contact with these partners (e.g., extreme anxiety when a sexual encounter presents itself) or a low sexual desire for these partners. Sexual aversion disorder and HSDD issues often arise within the context of couples--as, for example, when a "discrepancy of sexual desire" is diagnosed. Asexuality, in contrast, can be defined as the absence of a traditional sexual orientation, in which an individual would exhibit little or no sexual attraction to males or females. One such model of asexuality was developed by Storms (1980; see also Berkey, Perelman-Hall, & Kurdek, 1990). Storms classified heterosexuals as individuals who are highly attracted to the other sex (i.e., high in heteroeroticism), homosexuals as individuals who are highly attracted to the same sex (i.e., high in homoeroticism), bisexuals as individuals who are highly attracted to both sexes (i.e., high in both heteroeroticism and homoeroticism), and asexuals as individuals who are not attracted to either sex (i.e., low in both heteroeroticism and homoeroticism). In this study, I undertook the investigation of lifelong asexuality, defined as having no sexual attraction for either sex. Note that the definition of asexuality here concerns a lack of sexual attraction to either sex and not necessarily a lack of sexual behavior with either sex or self-identification as an asexual. Sexual behavior and sexual self-identification are of course correlated with sexual attraction, but, for a variety of reasons, one's attraction to men or women and overt sexual behavior or sexual self-identification may have a less-than-perfect correspondence. It is of note that many sexual orientation researchers have recently emphasized sexual attraction over overt behavior or self-identification in conceptualizing sexual orientation (e.g., Bailey, Dunne, & Martin, 2000; Bogaert, 2003b; Money, 1988; Zucker & Bradley, 1995). One fundamental question for the present research was the prevalence of asexuality. Is it as prevalent as other atypical sexual orientations such as same-sex attraction or is it extremely rare? Given the paucity of research on the subject, one might expect asexuality, particularly life-long asexuality, to be very unusual. A very low level of asexuality is also predicted from evolutionary models of human behavior because one would expect strong selection pressures against such nonreproductive tendencies. On the other hand, same-sex attraction is also clearly a nonreproductive orientation, and yet its prevalence over time and across societies continues to challenge evolutionary theorists (e.g., Bobrow & Bailey, 2001).