Genetics & Homosexuality, Are people born gay,The Biological basis for sexual orientation

On a twist on homosexual twin studies, an Australian research group examined the question of whether homophobia was the result of nature or nurture.
21 Surprisingly, both familial/environmental and genetic factors seemed to play a role.

by Rich Deem


Born Gay?
There is a common belief among liberals that people are born either gay or straight. Conservatives tend to believe that sexual orientation is actually sexual preference, which is chosen by the individual. This page represents a review of the scientific literature on the basis for homosexual orientation.

Rich Deem
Are people born gay or straight? Much of the current media sources assume the question is a solved scientific problem with all the evidence pointing toward a biological (probably genetic) basis for a homosexual orientation. Contrary to this perception, the question has been poorly studied (or studied poorly), although there is some evidence on both sides of question. In addition, many of the initial studies, which were highly flouted by the media as “proof” for a biological basis for homosexuality, have been contradicted by later, more thorough studies. This evidence falls into four basic categories:

1. Brain structure

2. Possible hormonal influences

3. Concordance of homosexuality in twins

4. Concordance of genetic markers in siblings

Why does it matter?
Until a few years ago, sexual orientation used to be called sexual preference. Obviously, the two terms denote significant differences in the the manner by which sexuality develops. A preference is something that is chosen, whereas orientation is merely something that defines us. The differences are potentially important regarding how the law applies to those who are gay. If homosexuality is not chosen, but actually is a biologically-determined characteristic over which we have no choice, then laws should not treat gays and straights differently, since homosexuality would be equivalent to one’s race, over which we have no control.


Other matters examined are:

  • Sexual orientation – brain studies
  • Hormonal influences
  • Twin studies
  • Genetic studies – the “gay gene”
  • Sexual preference or orientation?
  • Homosexuality and Darwinism
  • Real genetic studies?