Con to the question "Is Sexual Orientation Determined at Birth?"
"While biology certainly plays a role in sexual behavior, no 'gay gene' has been found, and whatever natural-science data exists for inborn sexual orientations is preliminary and disputed. So to date, the totality of the scholarly research on homosexuality indicates gayness is much more socio-cultural than biological…
[S]exual orientations are specific to our culture, and thus not basic human nature. In tech-speak, that means being gay is in the software of some people’s lives, but it’s in nobody’s hardware."
"Nobody Is 'Born That Way,' Gay Historians Say," dailycaller.com, Mar. 19, 2014