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Theories on Homosexuality

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Homosexuality linked to genetic component

More and more research in the area of homosexuality explores the connection between genetics and the development of a homosexual lifestyle. While further research needs to be conducted in this area, many studies have found that there appears to be a fairly strong biological basis to homosexuality.
          *For both male and female identical twins, if one twin is homosexual, it is likely that the other twin will
            be homosexual as well. This same finding is seen in biological relatives (as opposed to adoptive
            relatives) (02).
          *Gay men are 2 times as likely to be gay if his brother is gay. These results suggest that 50% of your
            being gay is due to genes (09).
          *Male homosexuality is more common on the maternal rather than the paternal side of the family,
            suggesting an X-linked trait (02). This means that if a male is homosexual, then there is a strong
            chance that he has an relative on his mother's side of the family who is homosexual as well.
          *One gene-mapping study found that in a sample of 40 pairs of homosexual brothers, 33 (83%) of
            them had identical segments of DNA on the X chromosome. This finding suggests that the "gene"
            for homosexuality may be on the X chromosome (02).
          *Simon Levay in The Sexual Brain found that the hypothalamus appears to be smaller in homosexual
            men when compared to heterosexual men (09).

Genes play an important role in sexuality, as they can modify brain structures, which in turn can alter the
amount of sex hormone produced in the body. This change can lead to homosexual feelings and/or behaviors (02). To read Yvett C. Schneider's contrasting argument to this theory, clilck here

The best explanation for homosexuality lies in the middle of both theories: a combination of genetic and environmental factors.

Related articles

Articles related to the subject of biology and homosexuality can be found on NARTH's website (these articles generally are against a biological basis explanation for homosexuality).
            "New Evidence for Biological Influence on Gender"
            "The Innate-Immutable Argument Finds No Basis in Science"
            "Is There a 'Gay Gene'?"
            "The Fading 'Gay Gene'"
            "Is Sexual Orientation Fixed at Birth?"
            'How Might Homosexuality Develop? Putting the Pieces Together"