Monday, June 05, 2006

How Can Homosexuality Be Genetic

When it's obviously maladaptive? I have encountered a few theories here and there which try to explain how a trait that seriously hinders reproductive success could nevertheless exist in around 5% of the population.

One that comes to mind is the idea that homosexuals are good at helping the over all family survival (they would, therefore, further their own genes through their family members).

Another idea is that gays were pressured to marry and reproduce by a culture hostile to their sexual preference. This seems reasonable for at least the last several thousand years (unless homophobia is itself genetic).

I have my own theory (which I am quite certain is nothing new, I just haven't seen it). What if several reproductively positive genes (intelligence, creativity, or a great fashion sense) combine to predispose one to homosexuality? These genes would aid reproductive success alone or in some combinations, so they would be propelled from generation to generation. It would only be in a particular combination that they would predispose one to homosexual preference.

Comments on "How Can Homosexuality Be Genetic"

 

Anonymous Anonymous said ... (4:15 PM) : 

Hans,

I knew some identical twins growing up. Identical not fraternal, thus they shared the same genes. From an early age, all the kids knew that one was gay and the other was not. They acted differently and had completely different personalities. By the time we all got to college, our suspicions were affirmed as the "gay acting" brother came out. While this is a mere anecdote, I offer it for what its worth.
LN

 

Blogger Hans Gruber said ... (1:41 PM) : 

The twin studies suggest a correlation for homosexual twin males. The best evidence here is suggestive of a genetic role for at least male homosexuals. A not insigificicant number of male twins, however, fail to both develop homosexuality. From what I gather, female twin studies show little to no correlation.

An alternative environmental explanation is found with Gregory Cochran. Here's a piece more or less describing it:

http://blogs.law.harvard.edu/calebcrain/gaygerm

 

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