Identical Twin Studies Prove Homosexuality is NOT Genetic

It doesn't matter what you tell anti-gay homophobes; they won't change. (Just FIGHT them back.)

 

As a Christian and biologist, I believe there is a genetic predisposition to homosexuality. The environmental influences are likely more important, but both are needed.

 

Sooooo its not determined by genetics. Possibly their choice is influenced by genetics.

 

So do you think all sambia men are genetically predisposed to homosexuality? Or do you think all Sambia men are culturally predisposed to homosexuality.
http://lrivera0327.tripod.com/

 

Truth be told, it doesn't.

We already protect traits that aren't immutable -- like religion.

No one is born Christian, for example. That's definitely a choice.

 

Exactly!!!

 

No, I never said either. The sambia's ignorance of biology, and being steeped in environmental tradition, makes your questions moot.

 

I don't care if homosexuality is genetic or choice. Individuals have every right to do with their body, property, and lives what they wish.

Scientific studies on homosexuality, while interesting, shouldn't change anything.

 

Actually you did when you said "both are needed."

 

I simply meant that a biological predisposition is needed to be influenced by environmental factors, for homosexuality to be manifested. I doubt that genetics is all that is needed, nor is the environment and choice the only thing needed.

 

I think the Sambia tribe shows that no biological predisposition to homosexuality is needed. The enviroment alone can develope homosexuality.

 

LMAO...Right-wing "science" at its usual worst.
My mother and aunt were identical twins.
Over the years, i have taught scores of identical twins as a teacher.
In every single case, they had distinctly different personalities and temperaments.
Your so-called expert is an idiot with an agenda.

 

The question, of course, is why the opinion of anyone in the "scientific community" should be taken seriously in this matter.

No one has an answer that doesn't amount to an appeal to authority, guaranteed.

 

What school are you sending your son too exactly?

 

Posting the opinion of a crackpot who has no credentials in the field concerning which he opines does not lend any credibility to one's prejudice.

In fact, it tends to discredit it.

 

http://hawaii.edu/PCSS/biblio/articles/1961to1999/1993-homosexual-orientation-in-twins.html

Twin pairs in which at least one twin is homosexual were solicited through announcements in the gay press and personal referrals from 1980 to the present. An 18-page questionnaire on the “sexuality of twins” was filled out by one or both twins. Thirty-eight pairs of monozygotic twins (34 male pairs and 4 female pairs) were found to have a concordance rate of 65.8% for homosexual orientation. Twenty-three pairs of dizygotic twins were found to have a concordance rate of 30.4% for homosexual orientation. In addition, three sets of triplets were obtained. Two sets contained a pair of monozygotic twins concordant for sexual orientation with the third triplet dizygotic and discordant for homosexual orientation. A third triplet set was monozygotic with all three concordant for homosexual orientation. These findings are interpreted as supporting the argument for a biological basis in sexual orientation.

It is clear that the question of nature vs. nurture remains only partially answered by the present study. If Kallmann’s and Schlegel’s near 100% high rates of concordance for MZ twins had been confirmed, the issue would be far more clear-cut. We are left then with the conclusion that biological factors are strongly operating in the determination of sexual orientation with the precise nature of these factors yet to be understood. Such was the conclusion presented previously by the present authors (Diamond, 1965, 1976, 1979, 1982, 1993, in press; Whitam and Mathy, 1986). As with other classic questions in the sciences, attempts at final answers are only partially successful and beget still other scientific puzzles.

Interesting- rather than talking of a 'gay gene'- the author talks of 'biological factors'.

Going back to the OP- why didn't he provide any links to these studies?

- - - Updated - - -

http://www.foxnews.com/health/2012/12/11/homosexuality-ultimately-result-gene-regulation-researchers-find/



The findings add to past research suggesting gay men haven't died out, because female relatives of gay men tend to have more children on average than other females. The study researchers specifically found that two genes passed on through the maternal line could produce this effect.

Hormones, epigenetics and orientation

Rice and his colleagues focused on epi-marks, which are molecular changes that act like temporary "switches" to turn genes on and off. If a gene is a blueprint, the epi-mark is the construction foreman who makes sure the product gets built. An epi-mark also determines when, where and how much a gene is expressed, according to the National Institute for Mathematical and Biological Synthesis.

These molecular switches are usually erased very early in the developmental process, but they can be passed down from generation to generation, too, Rice said.

Some epi-marks are particularly important during fetal development, when they promote normal physical development in the sexes despite natural variations in testosterone during pregnancy. Researchers know that fetal exposure to too much testosterone can masculinize the genitals, brain or behavior of a genetically female fetus. Likewise, too little testosterone can make a genetically male fetus more feminized. [Image Gallery: Fetal Development in Womb]

But here's the catch: There's lots of overlap between the levels of testosterone male and female fetuses get exposed to. That means there must be another side to the story, Rice and his colleagues wrote.

That side appears to be epigenetics, Rice said.

"Early in development, we think these epi-marks are laid down so that girl fetuses will be relatively insensitive to testosterone and male fetuses will be relatively sensitive to testosterone," Rice said.

Biological behavior

Thus, if an epi-mark that kept a mother from getting exposed to high testosterone in development gets passed on to her son — the opposite sex — it could desensitize him to testosterone, contributing to his sexual preference for men. Similarly, if a male-specific epi-mark from dad gets passed to a daughter, it could "masculinize" her sexual preference, making her more interested in women. [5 Myths About Gay People]

These findings could explain why twin studies show that homosexuality runs in families, but no "gay gene" can be found, Rice said. In identical twins, there's about a 20 percent chance that if one twin is gay, the other will be too. If genetic change were responsible for homosexuality, you'd expect a much higher match, Rice said. Epigenetics, however, can explain the heritability without the need for a specific genetic change.

The hypothesis could be tested by examining epigenetic marks in parents of kids with gay versus straight offspring, Rice said. There are, of course, concerns that this knowledge could be used by parents who want to avoid gay offspring, Rice said, but that concern already exists around certain hormonal conditions in utero, which are known to contribute to an increased chance of offspring being lesbians.

"That cat's already out of the bag," Rice said. He added that an understanding of the biological underpinnings of homosexuality could help emphasize that same-sex behavior is not "unnatural."

"In fact, it's a major part of the natural world," Rice said. Fourteen percent of Western gulls raise chicks in female-female pairs, he pointed out. And 8 percent of male sheep show zero interest in fertile ewes, but get sexually excited by other rams.

"We think that people who are gay or lesbian have a right to know, what is the biological foundation for this condition?" Rice said.

 

I dont have any kids. Got anything relevant to the topic of discusion? .....I AM NOT THE TOPIC OF DISCUSSION.

 

Making the study group pretty much useless as to making determinations about the population as a whole.

 

You need to contradict something in the study, not simply label it right wing. Nothing whatsoever in the paper even as much as suggested that people who are "genetically identical" also have identical "personalities and temperaments". Sooooo just what is it you disagree with. Nothing I suspect. You just dont like it being stated.

 

You were the one who brought up anal sex being taught in schools.

 

Thats because the twin studies show that sexuality isnt determined by genetics.

 

Yes I am. Did you have a point you wanted to make?

 

Okay- lets not make it about you- what school were you speaking about?

 

Oh but the author specifically says that can't be determined yet. Can you point to any recent twin study that says conclusively that sexuality is not determined by genetics?

But the authors say that the evidence shows that it is some sort of biological factor, as homosexuality appears to run in families.

Like being left handed.

 

Yes. The point is that you brought up anal sex being taught in schools, and then when someone asked you what school you're sending your kids to, you deflected and tried to not make it about you.