Tweet
Originally posted by MrFun
When I used to have a stronger belief in the genetic theory, I did my own research report on sexual orientation development.
Here is part of my report on twin studies:
"Another different theory developed in the 1980s was formulated by Richard Pillard and James Weinrich. They wanted to determine if homosexuality clustered in families (LeVay, 174-177). Are siblings of gays or lesbians more likely themselves to be gay or lesbian than siblings of heterosexuals? From one study, it was found that among brothers of heterosexual men, about 4% were homosexuals or bisexual. Among brothers of gay men, about 22% were homosexual or bisexual. From four separate studies, it was found that among the sisters of heterosexual women, 0% to 11% were lesbian or bisexual. With sisters of lesbians, 5% to 25% were lesbian or bisexual.
However, the observation that homosexuality is familial is not in itself proof of genetic influence on sexual orientation since there could be many environmental mechanics involved. Pillard and others performed studies on twins. These studies came up with concordance rates for homosexuality in monozygotic2 twins that are much higher than in dizygotic3 twins. In one study, 52% of monozygotic co-twins of gay men were themselves gay, while only 22% of dizygotic twins were gay. For lesbians about 48% for monozygotic siblings and only 16% for dizygotic siblings. To account for the possibility of gay or lesbian co-twins who would readily participate in these studies, Michael Bailey and his colleagues set a broad range between 30% and 75% for both men and women who would be gay or lesbian. Another weakness with these studies is that one has to consider non-genetic factors influencing sexual orientation. However, these studies offer substantial evidence that there is genetic influence."
END OF MRFUN'S REPORT
This is only a brief touch on this -- whole books have been written on this one particular theory, of course.
But now, I no longer have as strong a belief in the genetic theory anymore.
When I used to have a stronger belief in the genetic theory, I did my own research report on sexual orientation development.
Here is part of my report on twin studies:
"Another different theory developed in the 1980s was formulated by Richard Pillard and James Weinrich. They wanted to determine if homosexuality clustered in families (LeVay, 174-177). Are siblings of gays or lesbians more likely themselves to be gay or lesbian than siblings of heterosexuals? From one study, it was found that among brothers of heterosexual men, about 4% were homosexuals or bisexual. Among brothers of gay men, about 22% were homosexual or bisexual. From four separate studies, it was found that among the sisters of heterosexual women, 0% to 11% were lesbian or bisexual. With sisters of lesbians, 5% to 25% were lesbian or bisexual.
However, the observation that homosexuality is familial is not in itself proof of genetic influence on sexual orientation since there could be many environmental mechanics involved. Pillard and others performed studies on twins. These studies came up with concordance rates for homosexuality in monozygotic2 twins that are much higher than in dizygotic3 twins. In one study, 52% of monozygotic co-twins of gay men were themselves gay, while only 22% of dizygotic twins were gay. For lesbians about 48% for monozygotic siblings and only 16% for dizygotic siblings. To account for the possibility of gay or lesbian co-twins who would readily participate in these studies, Michael Bailey and his colleagues set a broad range between 30% and 75% for both men and women who would be gay or lesbian. Another weakness with these studies is that one has to consider non-genetic factors influencing sexual orientation. However, these studies offer substantial evidence that there is genetic influence."
END OF MRFUN'S REPORT
This is only a brief touch on this -- whole books have been written on this one particular theory, of course.
But now, I no longer have as strong a belief in the genetic theory anymore.
What made your beleif in genetic causation weaken?
Comment