Being female or male is innate as well but has nothing to do with the brain structure. There is no such thing as "a female brain" or "a male brain", therefore I can not see how one can have "a gay brain" when there is no such thing as "a female" or "a male" brain. Imagine the brain of a female is structured like the brain of a male in her household, would that make this female male as well? No, it doesn't. She would just be a female and whether her brain is structured like the brain of males has nothing to do with her being a female. The same is true for gay people, their being gay has nothing to do with whether their brains are structured like the brains of their opposite sex or their same-sex. I am sure just as there are many for what is male or female reasons that have nothing to do with what one's brain is structured like, there are many reasons for being gay that have nothing to do with what a gay human's brain is structured like.