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Gays make great uncles: Maybe that's why they're still among us

February 5, 2010 | 11:58 am

Evolutionary biologists have long scratched their heads over homosexuality in men: If there is a genetic component to male homosexuality--a view for which there is considerable evidence--then why has that gene persisted to this day? After all, if one were disinclined to spread one's seed in places where it would result in offspring and extend your bloodline, evolutionary reasoning would tell you that genetic propensity would disappear.

And yet they live among us--sons, brothers, dads and uncles. Especially uncles.

A new study conducted in Samoa suggests that gay men's avuncular ways--their willingness to  love, baby-sit, teach and buy toys for their nieces and nephews--may be the key to the survival of the gene that may predispose some men to sexual attraction to other men.

That's the conclusion that emerges from a study that looked at the fa'afafine of Samoa--male homosexuals, who are considered a distinct gender neither male nor female, but who live their lives integrated seamlessly into their extended families.

The study, which appeared in the journal Psychological Science compared the avuncularity--the dedication shown to nieces and nephews--of the fa'afafine--with that demonstrated by heterosexual Samoan men and heterosexual Samoan women.

Spoiler alert: If you need money, go to your gay uncle first. He may be here today because of the greater likelihood that he'll pull out his checkbook and deliver the goods. In fact, he might even drive you to the bank to deposit it, too.

Gay uncles, the study of Samoans found, have a pattern of devoting themselves to their siblings' offspring, selectively paying them more attention than they do unrelated children. Their inclination to dedicate themselves to their nieces and nephews was found by researchers to be not only greater than that of straight uncles and aunts, they also favored their nieces and nephews for attention over other kids more strongly than do heterosexual men and women.

Having such an attentive gay uncle confers a selective advantage on a child, making it more likely that a child will survive, thrive, prosper and reproduce, researchers surmised. Because of the gay uncle's availability and assumed role as "helper in the nest," researchers say, the child is more likely to grow up and carry his or her uncle's genes forward indirectly (and perhaps in an attenuated form), keeping the "gay gene" alive.

The authors of the study, Paul L. Vasey and Doug P. Vander Laan of the University of Lethrbidge, don't mention it, but the kin selection hypothesis might also help explain the oft-cited tendency for gay men to be the younger brothers in large families of males.

There are interesting biological reasons why that might so--researchers have speculated that mothers who have borne many boys may pump the womb full of female hormones to counter a build-up of androgens, and that influences the development of their brains in utero. But if gay men's evolutionary value is based on their dedication as uncles, they would have to have a passel of older brothers (and sisters too perhaps) to produce offspring for them to "uncle."   

Want to read a really vintage study on the genetic bases of homosexuality? Check this out.

And if you don't believe in evolution--or that homosexuality in men may have biological roots, but is rather a lifestyle chosen to affront--well then, this study won't help explain anything for you. Good luck finding an alternative.

-- Melissa Healy