Based on what evidence? some ones guess? Are you going to quote the same pyschiatrists who once characterized homo sexuality as a sexual deviation.
Why do you think some 5% of the population are gay? The devil? Hollywood? Watching Ellen Degeneris? Liberal college profs?
now you are trapped so you do the leftist thing and either change the subject or create non sequitors. In know some people, especially women believe they are gay because they were molested when they were young. I believe some people choose to be gay... certainly bi sexuals. I believe some people were assigned gender at birth and therefore may have been incorrectly assigned. And I will take the word of some people who believe they were born that way from birth.