Gregory Cochran suggests that a major cause is likely to be one or more diseases, suggesting a virus is probably involved. He lays this out in a series of blogposts linked from the article below.
Updated, 10/17/15. See below! In this post, I will review Gregory Cochran’s “gay germ” hypothesis. I wanted to make an index of Cochran’s posts from his and Henry Harpending’s blog West Hunter that discuss it. These posts don’t seem to all show up under the “Homosexuality” category there, and I...
www.unz.com
To sum it up very very briefly- male homosexuality looks
exactly like the sort of behaviour we expect from an infection, especially a viral one, perhaps fungal, bacterial, or otherwise.
Avoiding human reproduction to instead get barebacked by hundreds of guys with AIDS is something that takes a lot of explaining. It looks a lot like the behaviour of rats suffering from a toxoplasmosis attack. It also looks like a lot the other links between viruses and mental illness that have been identified. The selfish gene- in this case perhaps carried by RNA rather than DNA- cares only about the host that the gene itself rides along in, the infectious agent. It doesn't give a fuck about reducing its host's lifespan, or their fecundity.
What it does not resemble is any of the explanations that are politically correct and fundable, from epigenetics, to the absolutely ridiculous 'gay uncle' theory. Anyone suggesting the 'gay uncle' theory is even remotely plausible is clearly fucktarded. If I was a cave-dwelling sodomite (in the prehistoric era, as opposed to now), you had better believe I would not be spending my excess resources allowing my relatives to raise 3-4 more children than they might have otherwise. That meat would be kept back so I could relax more and bribe cavetwinks to give me a handy.
So why aren't more people aware of this, the most plausible explanation for the prevalence of homosexuality in 'civilized' societies such as ours? The reason is simple. If a study provides proof showing a link between something like a viral infection in early childhood and homosexuality, even if the disease is one that is carried in the general population and no more likely to be 'catching' from an adult homosexual than any other adult, there would be an orgy of violence as people throughout the third world executed homosexuals en masse.
There is no possible way that any scientific funding body will risk being associated with a mass homocide.
Heck, even if the 'eat da poopoo' man could be prevented from learning about such a discovery, Pintrest would spread it throughout the world of white suburban moms who "don't have anything against gays, would be perfectly happy with a gay son, but just want him to be as happy as possible" within days. If there was not already a vaccine for the virus, one would be found, and the company that owned it would make a killing.
But.. at the same time, this would be strongly opposed by adult male homosexuals. This group generates a metric shitton of revenue for those same drug companies that would profit from the gay vaccine, from the umpteen AIDS drugs and all the associated conditions that the virus, and the antiretrovirals cause.
And they would also likely be in a similar position to the deaf people who oppose cochlear implants. Everyone loves children. Deaf people love deaf culture. They love deaf children signing in a cute fashion- reasonable enough. Likewise, male homosexuals love new twinks showing up at their standard fuck parties. Deaf people are a marginalised group but opposition to cochlear implants is a real movement. Would many homosexuals, a group known for having a greater disposable income than sexually well-adjusted people, not pull similar stunts?
Cochran has held several academic positions both within physics and anthropology departments, and is somewhat of a polymath. I invite people to fuck around and find out in his comments.