There had been statistical research done that indicates there is very probably a biological basis for homosexuality. This would imply that it is not a "choice." Let me post some stuff from my biopsychology textbook:
Genetics:
Homosexuality is 2-7 times higher among the siblings of homosexuals than it is in the population. Identical twins are more concordant for homosexuality than fraternal twins or non-twin siblings. The heritability (percentage of the variation among individuals in a characteristic that can be attributed to heredity) estimates of homosexuality range from 31-74%. (This is accounting for adoption, by the way, or else it would not even be mentioned.)
It was noticed that gay men have more gay relatives on the mother's side than on the father's side. Following up on this, researchers checked the X chromosome (the one paired with Y) in these men, looking at the genes of gay brothers. In 64% of the pairs, the brotherhood shared the same genetic material on one end of the chromosome. A further study supported this. Although this does not mean that they found a "gay gene," (and in fact there would have to be other places that effected sexual orientation as well), there is really no question (statistically) that homosexuality does have some heritable basis.
Hormones:
Doctors have tried giving gay men testosterone to "make" them heterosexual. It didn't work; all it did was increase sexual activity. Studies have since been done comparing hormone levels on homosexuals and heterosexuals, and the hypothesis that hormones are lacking or in excess has not been supported. If hormones are to blame, it's prenatal exposure. Hormonal manipulation has caused some animals to have same-sex sex preferences, but this is controversial and not supported very well.
The question of animals, however, raises an interesting point: There are homosexual animals. 10% of male sheep prefer other males as sex partners. Some female gulls on Santa Barbara Island have been observed in "lesbian" pairs. The gulls perform normal courtship and maintaining rituals.
Brain Structures:
There are three main brain structures which have thus far been identified as having different sizes in homosexuals and heterosexuals. The third intersisital nucleus of the anterior hypothalamus was found in a study to be half the size in gay men and heterosexual women as in heterosexual men. This structure is involved in sexual activity in animals but its role in humans is unknown.
The suprachiasmatic nucleus was found in a study to be larger in gay men than in heterosexual men and contained almost twice as many cells which secrete the hormone vasopressin. This structure regulates the female reproductive cycle in rats and controls daily cycles in rats and humans. Back to the hormones, when male rats were treated prenatally with a chemical that blocks the effects of testosterone, the number of vasopressin-secreting cells in this area increased.
The anterior commisure was found to be larger on another study in gay man and heterosexual women than in heterosexual men. This is one of the structures connecting the two hemispheres of the brain.
Other differences worth noting:
Gay men and heterosexual women score lower on spatial tasks and higher on verbal ability than heterosexual men.
Although little studies have been done on lesbians, two physical characteristics have been found to distinguish heterosexual women from lesbians, which would support a biological basis in women for homosexuality despite seeming somewhat trivial. In men, the ring finger is usually longer, in women, they are about the same length. The index-to-ring-finger ratio in homosexual women is the same as in men, on average. There is a faint sound given off by the inner ear when it is stimulated, called click-evolved otoacoustic emissions. The response is weaker in lesbians and men (heterosexual and gay) than in heterosexual women.
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Having posted all that, I don't think it's "abnormal" and that it's a biological deviation; I'm putting this up, as I said, to help support the idea that it is NOT a choice.
My opinion: I don't think it's morally wrong.
Last edited by Serissa on 19 Jul 2005, 9:33 pm, edited 1 time in total.