From the excellent EurekAlert!:
Male homosexuality doesn’t make complete sense from an evolutionary point of view. It appears that the trait is heritable, but because homosexual men are much less likely to produce offspring than heterosexual men, shouldn’t the genes for this trait have been extinguished long ago? What value could this sexual orientation have, that it has persisted for eons even without any discernible reproductive advantage?
One possible explanation is what evolutionary psychologists call the “kin selection hypothesis.” What that means is that homosexuality may convey an indirect benefit by enhancing the survival prospects of close relatives. Specifically, the theory holds that homosexual men might enhance their own genetic prospects by being “helpers in the nest.” By acting altruistically toward nieces and nephews, homosexual men would perpetuate the family genes, including some of their own.
Two evolutionary psychologists, Paul Vasey and Doug VanderLaan of the University of Lethbridge, Canada tested this idea for the past several years on the Pacific island of Samoa. They chose Samoa because males who prefer men as sexual partners are widely recognized and accepted there as a distinct gender category—called fa’afafine—neither man nor woman. The fa’afafine tend to be effeminate, and exclusively attracted to adult men as sexual partners. This clear demarcation makes it easier to identify a sample for study.
Fascinating article — if, at the very least, only to hear of the Fa’afafine as an accepted third gender in Samoa — and an interesting theory… Although I’m not sure where it leaves lesbians. Are they super aunties? Article at EurekAlert!
