Bisexual people, transgender individuals, adult babies and diaper lovers, furries, gynandromorphophiles (men attracted to trans women with penises), pedophiles, voluntary eunuchs, and straight crossdressers—I have studied them all. To what end? Why should anyone study persons with unusual sexual identities? There are two reasons that motivate researchers, and, as far as I can tell, they never coexist in the same researcher, because they cannot.

When I study unusual sexual identities, I want to understand them. For instance, what is their underlying motivation? Do people often possess more than one, or do they shift from one to another? I am also interested in the ways that sexual identities inform broader questions. For example, is there any value to concepts such as “paraphilias” (atypical sexual arousals formerly referred to as “sexual perversions” or “deviations”) or “erotic target identity inversions” (i.e. paraphilias that involve the person themselves being whatever object their sexual desires are centered on)?