This study presents data bearing on an evolutionary developmental model of male homosexuality. This model hypothesizes that a predisposition toward elevated kin-directed altruism among homosexual males is expressed in childhood as elevated concern for close attachment figures (e.g., parents) and proximally influenced by the concomitant behavioral expression of femininity. We examined whether homosexual males recalled such elevated concern for parents during childhood and considered its association with recalled childhood gender behavior. Heterosexual and homosexual males and females (N = 524) provided measures of recalled childhood gender behavior, concern about parental wellbeing, and other potential sources of separation anxiety. Heterosexual males experienced significantly less anxiety about parental wellbeing than all other groups. Recalled separation anxiety was positively correlated with childhood femininity for heterosexual females and homosexual males. The heterosexual sex and male sexual orientation differences in concern about parental wellbeing were accounted for by childhood feminine behavior. These findings are consistent with the proposed evolutionary developmental model. We discuss possible proximate influences that facilitate the development of this putative evolved predisposition toward elevated kin-directed altruism among homosexual males as well as limitations and future directions.
Male homosexuality is partially influenced by genes (Alanko et al., 2010), but also reduces reproduction (Schwartz, Kim, Kolundzija, Rieger, & Sanders, 2010). The kin selection hypothesis (Wilson, 1975) posits that these genes nevertheless persist because homosexual males behave altruistically toward close genetic relatives, thereby increasing kin’s reproduction and passing on these genes indirectly. Consistent with this hypothesis, Samoan fa’afafine (i.e., same-sex attracted transgendered males) report greater altruistic tendencies toward kin compared to Samoan men and women; however, Western and Japanese gay men do not report elevated kin-directed altruism (reviewed in Vasey & VanderLaan, 2014).
To shed light on these cross-cultural discrepancies, VanderLaan, Gothreau, Bartlett, and Vasey (2011a) proposed an evolutionary developmental model informed by cross-cultural research on childhood separation anxiety (i.e., distress associated with separation from attachment figures). Elevated attachment to kin is important for motivating kin-directed altruism (reviewed in VanderLaan et al., 2011a). Despite discrepancies in kin-directed altruism between transgendered Samoan fa’afafine and relatively more masculine Western and Japanese males who identify as gay men, same-sex attracted males who recall being more female-typical as children appear to experience elevated attachment to kin during childhood. Samoan fa’afafine recalled elevated separation anxiety compared to men and women ( Vasey, VanderLaan, Gothreau, & Bartlett, 2011) while Canadian homosexual men recalled more separation anxiety than heterosexual men ( VanderLaan, Gothreau, Bartlett, & Vasey, 2011b). Similarly, in a clinical sample of boys, more extreme cross-sex behavior and identity was associated with elevated traits of separation anxiety ( Zucker, Bradley, & Lowry Sullivan, 1996).
Based on this information, VanderLaan et al. (2011a) hypothesized that, across cultures, feminine boys who exhibit same-sex attraction as adults experience elevated childhood separation anxiety as an early developmental expression of elevated kin-directed altruism. In a Canadian sample of heterosexual and homosexual men and women, the current study tested two predictions derived from this hypothesis to provide an initial assessment of whether VanderLaan et al.’s model is tenable. The first prediction was that if elevated separation anxiety is an early developmental expression of elevated kin-directed altruism, then same-sex attracted males should be especially prone to worrying about the wellbeing of close relatives during childhood given their heavy reliance on kin for genetic fitness. In contrast, other potential sources of separation anxiety (e.g., going to school) would be less likely to produce a male sexual orientation difference because they are not as directly relevant to kin’s wellbeing and, thus, indirect fitness. The second prediction was that positive associations between recalled feminine childhood behavior and recalled separation anxiety should mediate and account for group differences in recalled separation anxiety.
