Understanding variation in women's sexual attitudes and behavior across sexual orientations: Evaluating three hypotheses

Although evolutionary logic has provided abundant insight into how differential biological costs, mating opportunities, and exposures to psychosocial stressors shape functional variation in mating behavior among heterosexual men and women, it is less clear how such factors influence behavior among those who do not identify as heterosexual. Here, we evaluate three evolutionarily-informed hypotheses proposed to explain variation in women's sexual attitudes and behavior across sexual orientations. A sample of 328 women (111 heterosexual, 75 lesbian, and 142 bisexual; ages 18–36) completed questionnaires assessing their current sexual permissiveness, past sexual behavior, and past alcohol use. Lesbian and bisexual women reported more risky sexual (and non-sexual) attitudes/intentions and behaviors than did heterosexual women. The observed differences were best explained by increased psychosocial stress experienced by sexual minority (versus heterosexual) women.