The Allomothering Hypothesis: an Examination of the Adaptiveness of Female Sexual Fluidity in Self Identified Heterosexual and Mostly Straight Women

Abstract

Exclusive same-sex sexual behaviour is problematic from the viewpoint of evolutionary theory because one of evolutionary psychology’s fundamental tenets is that species need to survive and reproduce. I contend that female sexual fluidity is an evolved predisposition in heterosexual women and the behaviour evolved as a result of the need for allomothering— helping each other’s offspring survive—and also providing assistance with survival of the females themselves. The Allomothering hypothesis asserts that same-sex sexual behaviour can be adaptive in condition-dependent circumstances because it promotes pair bonds that ultimately contribute to the survival of offspring. A revised definition of sexual fluidity, one that is different from the traditional definition, was devised. In this dissertation the revised definition states “sexual fluidity occurs when self-identified heterosexual (straight) or predominantly heterosexual females experience short-term fleeting physical (sexual) attraction to and/or a deep emotional connection (like romantic love) with other females in a condition-dependent circumstance.” Four studies were conducted to find evidence in support of the allomothering hypothesis. The first study compared self-identified heterosexual (mostly straight) women and men in terms of same-sex sexual experience. Overall, women more than men have engaged in various dimensions of same-sex sexual behaviour. The second study compared pornography geared toward heterosexual women and pornography geared toward heterosexual men. Female same-sex sexual behaviour occurred in almost all the top selling movies for both heterosexual women and men. The third study tested the allomothering hypothesis by having self-identified heterosexual (mostly straight) women who have engaged in same-sex sexual behaviour rate the person they had the experience with on “good mothering traits.” The more the women enjoyed same-sex sexual behaviour, the higher they rated the person they had the sexual experience with. Various aspects of same-sex sexual behaviour among heterosexual (mostly straight) women and allomothering were explored. The final study was an assessment of captive Bonobos (Pan paniscus) at the Milwaukee Zoo. Bonobos are humans’ closest genetic relative along with Chimpanzees (Pan troglodtyes). The study examined the connection between female same-sex sexual activity among bonobos in relation to pair bonding, grooming, play, and allomothering.