biological or inherited?

Over the past couple of years, the idea that males are more likely to be homosexual as a result of having older brothers has been tossed around. However, I have never thought much of this theory due to the fact that personally, all the male homosexual friends and acquaintances I have are either the only child, are the oldest out of all their siblings, or have all sisters! So even if there is an iota of truth to the “older brother” theory, it does not explain homosexuality amongst all males.Recently, a Canadian study is revealing that perhaps homosexuality is due to more biological reasons than social reasons [ref: http://news.bbc.co.uk/2/hi/health/5120004.stm]. I have heard people say this too – that people “inherit” their homosexuality. But there needs to be proof of this, right? Well, here’s a synopsis of the news article I have linked to this entry:

Professor Anthony Bogaert from Brock University in Ontario, Canada revealed after conducting a study, that the idea of homosexuality related to having older brothers only exists when the brothers are from the same mother, and not if the brothers have been adopted or are half-brothers [have the same father, but not the same mother]. He suggested that a woman’s body may see the male fetus as “foreign”, prompting an immune reaction and creating antibodies which may affect the developing male brain. Scientists from Michigan State University said: "These data strengthen the notion that the common denominator between biological brothers, the mother, provides a prenatal environment that fosters homosexuality in her younger sons."

However, this study still doesn’t provide sufficient “proof” which satisfies me in showing that male homosexuality is biological. It also fails to show why an only child, older sons, sons with only female siblings, as well as female homosexuals are sexually-oriented in this fashion.

So in the end of all of this, as far as I'm concerned, we are no more knowledgeable in the reasons of homosexuality now than we were before. There are still those homosexuals who say they inherited their sexual orientation, and there are still those who say they chose to be gay. I wonder if there will ever be significant proof one way or the other.