Think about it for a second: if there were any sort of a biological basis for being gay, the idiots would not be prosyletizing and trying to make converts in the public schools, would they?
They would if it was a biological predisposition
In other words, if being gay was a result of biology AND environment, they would want to have every possible biologically-predisposed kid be exposed to a pro-hay environment to as to ensure they "turn" every potential recruit