If You’re Born Gay, How Can A Homo Have a Straight Identical Twin?

In the nature v. nurture debate over what causes The Gay, nothing makes a better scientific experiment than identical twins. Born from the same set of cells and raised together by their parents, this set of twins — with one gay, one straight — has National Geographic concluding that sexuality can’t all be in the genes. Then, what else?

Blame the hypothalamus and testosterone, we’re told.

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  • Wade MacMorrighan

    Oh gods, I can see someone who know they’re having a boy saying to the Doc., “Flood me with testosterone so I can have a NORMAL son!!!”

  • Tina

    I picture hulking, roid-rage teenagers kissing other hulking roid-raging teenage boys…

  • Qjersey

    There is a phenomena of “mirror twins” with one being right handed and the other left, so….

  • AlanInUtah

    I’ll take them both please! :)

  • TommyOC

    I’m an identical twin. I’m gay, my brother is straight and happily married to his wife. I’m right-handed (well, ambidextrous in some areas, hehe) and he’s left-handed. I’m also slightly taller.

    The question in this article gets asked of me repeatedly. And my layman’s answer mirrors the NatGeo conclusion. Genetics play a partial role and in-utero chemical interactions – and possibly chance? – play another.

  • sebastien

    Gays are natural selection. we’re a gift to humanity , god’s gift.

  • Dick Mills

    It’s something of a misnomer to suggest that in utero is “nurture”, at least in the way that most of the lying liars use the term nurture. To be clear, in the case of in utero, both genetics and “nurture” are purely biological in nature. The biological in utero environment has nothing to do with the way that children are raised after they are born. The later of which is what the lying liars take “nurture” to mean.

    So, to be clear, this National Geographic piece DOES NOT in any way suggest that the sociological environment a child is raised in will affect their predisposition to same-sex attraction. The only inference from this piece is that biology (and ONLY biology) is the most likely cause same-sex attraction.

  • Emmazon

    Sebastien – you are fanned! (I hope that’s the right word – love the post)

  • asa1973


    I’m also gay with an identical twin who is straight. I’ve also been asked this question all of my life (as an out gay man). And…I as well have given a layman’s answer that mirrors the NatGeo theory.

    After having so many gay men say, “either your brother’s gay, or you are straight, but you can’t be one of each,” it’s nice to see science start to conclude what I have believed all along…

  • romeo

    I’ve known 4 identical gay twins. All pairs were completely gay. Suspect that is the most common. I discussed the “cause” scenario in another thread. I think when and if answers are found for sure, it will be more than one cause, but biological in nature for the most part, either genetic, or in utero, or who knows what else that hasn’t been discovered.

    Fascinated by the comment about “mirror image” twins. Wonder if researchers took that into consideration?

  • Brian

    “If You’re Born Gay, How Can A Homo Have a Straight Identical Twin?”

    Ahhhh, they went to Church and you didn’t.

  • romeo

    Incidentally, I read that testosterone treatment was tried years ago on gay men. All it produced was more aggressive homosexuals. LOL


  • Daniel

    Maybe it is completely genetic, just not the offspring’s genetics. Perhaps it is the mother’s genetics and how her body processes having offspring.

  • Attmay

    @6 Sebastien:

    We are the reason there is such a thing as Western Civilization. Without us, there would still be a West, but it wouldn’t be Civilization.

  • Danny

    What does one twin being straight and the other gay prove? Identical twins aren’t exactly alike even as newborn infants with absolutely no experiences.

    All this does prove is that science can’t possibly answer everything. Some things in life aren’t meant to be known or answered. Not everything needs an answer.

    Why don’t they try finding the meaning of life and come to the conclusion that there isn’t one just because they can’t find the answer to that either…

  • redball81

    I’m sorry but this video keeps saying sexual “preference.”


  • fuzzypony

    Considering all the science I’ve read, and based on my own experience as a biologist, I’d say that being gay is largely determined by chemistry in utero. If genetics were very heavily involved… well, most of us don’t breed, so how could a similar frequency of “gay” genes be maintained in every population on earth if those genes are not being passed on? There might be some genes that, in some forms, predispose us to a certain reaction when exposed to high levels of one chemical or another, but I sincerely doubt that there’s a single or even a group of “gay” genes. It’s a function of chemistry. Also, human sexuality is way more complex and fluid than fundies would have us believe, so there could literally be a hundred factors that go into your sexual orientation, the depth of your attraction to a sex, your gender identity, etc.

    In short, next time you mother tells you you’re going to hell, tell her that, biologically speaking, it’s probably all her fault.

  • AlwaysGay

    Dr. Reed at Harvard proposed a hypothesis which states homosexuality is maintained in species because the genes that carry it come from sperm that are close to the size of eggs which means it travels faster and is able to fertilize eggs quicker than sperm that are smaller than eggs.

  • Brandon

    Did any1 else guess right off the bat that the twin in black was the gay 1 b/f they even said it? I knew right away. lol. They need to devote a study to what causes “gay-face” b/c that can be so obvs sometimes.

  • Wade MacMorrighan

    Yeah, I knew which one was gay right away; his brother (the het.) had this almost defensive look in his face that read, “Don’t F with me!”, while his Gay bro. had a more welcoming facial expression.

    However, something else that I’ve love to see science explain is the evolutionary impetus for homosexuality at all! Surely if there was no purpose for it, than it would probably not occur; yet, apparently, it’s been developed and sustained through evolution in multiple animal species (including our own)–Why?

  • shea

    Tegan & Sara are also another pair of gay identical twins that you can add to the list. Genetics have exceptions in EVERY aspect; not just when it comes to sexuality. That’s why it’s such a fascinating field of study.

  • Trey

    …so, i’m wondering why they scanned the brain of the gay twin. They sort of just did it without saying why and they never mentioned it in the clip. Were they going to scan the straight twin and look for differences? The narrator seemed to be convinced that most people were either gay or straight, and homosexuality was caused by something breaking down. It seems more likely to me that most people are shades of bisexual, like me, and culture, upbringing and formative experiences biases us towards different things.

  • grant

    I find the clinical approach to understanding why I exist to be distasteful and creepy. One day in the future will I receive a letter from the government which says : “The verdict is in, you’re natural. Welcome to Society!”

    Fuck Heterosexuals and their inabilities.

  • B

    In No. 10 · romeo wrote, “I’ve known 4 identical gay twins. All pairs were completely gay. Suspect that is the most common.”

    If one is gay, the probability that the other is gay is about 52%. It’s about half that for fraternal twins. has a summary. BTW, genes basically encode the proteins a cell will produce. The behavior of those proteins does not have to deterministically set one’s sexual orientation even if one’s sexual orientation is set before birth.

  • hyhybt

    Identical twins don’t have the same fingerprints either; does that make them unnatural?

  • Ryan

    For those who ask about evolutionary purpose:

    An italian study has suggested that the same genes (if they exist) that cause homosexuality in males, may cause increased fertility in females. The females would have a greater net differential reproductive success, which is the driving force in evolution. This is just one model for the evolution and persistence of the “gay gene.”

    This all assumes, of course, that homosexuality is genetic, which it may not be. As others have said, it is more likely the result of the chemical environment in utero. If homosexuality is genetic, however, it must be explained in terms of evolution. Homosexuality as a genetic trait is far too maladaptive to have survived simply by chance.

  • Caleb


    In science, “preference” does not mean what you think it means. It does not imply choice at all. Granted, the public may not get the distinction, but it isn’t necessarily incorrect.

    Also, plenty of pairs of twins think they are identical and you couldn’t tell them apart, but that does not mean they are.

    Personally, I don’t care if it’s a choice, a condition that results from chemistry or biology or genetics. It shouldn’t matter whether it is a choice or not. You’re never going to convince those who don’t want to believe what they don’t want to believe no matter how much science you put in front of them (see: evolution). The goal should be to make people understand that it does not matter if it is a choice. It’s sex and love and as long as it is consensual, it shouldn’t matter to anyone.

  • B Stupid

    I am looking for some wikipedia info to cut and paste. Check back.

  • Ted C.

    Eh. All these people and their inane, endless theories about what makes you gay. It’s all so dehumanizing. None of the theories are ever right, and why do people care anyway? Why must we treat being gay as an oddity that demands an answer?

    Everyone knows that gay people are gay because they were blessed by God. That’s all you need to know.

  • romeo

    @ Ted C.: I’m with you. We’re a natural variation. We can see and feel things that straight people can’t. Convinced of that. The evidence of it is the art and science we’ve left throughout history. The ancient world never gave it a thought beyond defining certain norms for it reflective of the general misogyny. But it was totally accepted as a natural facet of human nature. We have been the victims of the unnatural aberrative cultural practices brought about in the main by monotheism, which hates the natural world and sets its sights on fantasies of the next.

    That said, it’s up to us to take our rightful place again in the world. None of those hogans are going to hand it to us. LOL

  • Lynn David

    Uhmm…. I’ve always heard/read that gay men have higher levels of testosterone, especially in utero. It’s because there isn’t the amount of aromatase to change testosterone into androgen and it is androgen which creates a heterosexual outlook. As to twins I always figured that it was just that different genes were expressed in either fetus early on; those from an X chromosome for the gay son and the Y chromosome for the straight son.

  • WTF?

    It’s genetic. Plain and simple. Even “identical” twins aren’t exact copies; differences, however minor, do exist.

  • Rainfish


    Research says erect gay penises are bigger:
    Uncovered Kinsey Report data show homosexual members have hetero ones by a head.

    By Hank Hyena
    Nov. 4, 1999

    Six inches is the average length of a male erection, right? More or less? More (6.32 inches) if you’re gay, apparently. And less (5.99) if you’re straight. Stiff homosexual organs are one-third of an inch longer, claims an article titled “The Relation Between Sexual Orientation and Penile Size” in the June Archives of Sexual Behavior.

    The phallus findings are based on archived data from 5,122 measurements of men’s schlongs obtained by the Kinsey Report from 1938-1963.

    But isn’t it penile chubbiness that matters more in sexual pleasure? Heteros lose this contest, too. The straight circumference is 4.80 inches, while gays wield a stout 4.95. Dr. Anthony Bogaert of Brock University in Ontario, Canada and Dr. Scott Hershberger of California State University-Long Beach co-authored the recent study, which is part of a larger study on the origins of sexual orientation and behavior.

    Reached by phone at his Ontario office, Bogaert generously answered my most probing questions about the penile research.

    Why on Earth would gay guys be heavier hung?

    “It might have something to do with prenatal hormones that affect the structure and size of genitalia and certain structures of the brain that ultimately affect sexual orientation,” Bogaert said. “If so, this would lend support to theories that believe there are biological factors affecting sexual orientation.”

    (for the rest of the article go to:



    OK…so the suggestion is that we (homo-men) are gay because we have been exposed to less testosterone in the womb, then why do we (on average) have bigger penises? Because we get less testosterone in the womb? Really?

    Yet, other studies have suggested that we are over-masculinized (i.e. hairier on average with bigger penises) because of our exposure to MORE testosterone than the average hetero-man who have smaller penises on average and less hairy bodies. Confusing isn’t it?

    Another approach — from the unscientific side of the blanket — may be spiritual.

    Reincarnationists (as a good as any other belief system) have suggested (from a spiritual perspective), that perhaps we just transfer the essence of our sexual/spiritual preference/orientation from one life to another.

    Sounds about as supportable as some of the so-called “scientific” research (read: speculation) so far (i.e. more questions than answers).

    So, if you believe in reincarnation, like hundreds of millions do, and if we were all both men and women at sometime in our continuing existence — then why not a naturally spiritual bisexual nature occurring with a preference leaning towards what was more satisfactory (or gender based) in a past life or lives?

    ….Just asking. :)

    Maybe sexual preference/orientation is more spiritual and less physical in origin.

  • jason

    Yes, I also lose interest in any study or anybody who uses the terms “sexual preference” instead of “sexual orientation”. Sexual preference is a subset of sexual orientation. Consider a gay man who chases after hairy men. His orientation is gay, his preference is hairy.

    How difficult is it to understand this concept?

  • alicia banks

    gaybashers are arrogantly ignorant!

    het twins that are male and female are born daily!

    this is no different than male and female het twins!

    bigotry blinds the blatantly logical for the illogic of insanity!

    alicia banks

  • Luffetz

    @Jason: Hearing words like “preference” and “homosexual” are grating in Science because they are always used with dripping hate in most other contexts. But in science, certain words do not mean the same thing as they do in laypersons’ language. “Theory”, for example, as a model for predicting future behavior, not a conjecture or guess (the news narrator screwed this up). “Preference” in science does not imply choice.

  • Totakikay

    I like National Geographic Channel (NGC), I watch it almost everyday. Have you guys watched Stephen Colbert’s episode today where he interviews California representative Jackie Speier? Colbert asks Jackie if scientists and doctors can change a person’s sexuality at birth through gene splicing. I personally would not want that to happen, and I find it un-Humanistic and un-Scientific. Their is nothing wrong with having a Lesbian, Gay, Bisexual, or Transgender child. Scientists, doctors, and politicians need to protect LGBT babies from unnecessary abortions and “ex-gay” gene conversions. Any of you guys have a good idea that will protect LGBT babies from such a terrible fate?

  • Ray

    I’m an identical twin with a straight brother. I find it extremely interesting that there are two others like me in these comments alone. I mean, how rare must we be?

  • romeo

    @totakikay #36: This is an interesting subject, and, of course, of concern to us here. However, my own thoughts are too complex on the issue for the economical glibness needed in these posts. But I would like to respond with a few things and a prediction.

    First of all, I think research in eliminating homosexuality from from the human race is already under way. Research into its causes is, in some scientific quarters, preparatory to that end. Scientists are human beings and subject to prejudice and rationalizing their prejudice just like any other human being.

    However, on the subject of gene “therapy,” it has not proven very successful yet in any of its applications toward other things. It remains only a potential benefit. It seems like it should work, but Nature keeps presenting further mysteries. Nature will always do that, and when it come to the subtleties of the human mind, she will do it in spades. What makes us straight, bisexual, gay is a vast complex of physiological interactions, it’s unlikely that a magic bullet could be found.

    That does not mean the attempt won’t be made. Here’s a prediction on the attempt to shove the entire human race onto one side of the sexuality spectrum — The gene or chemical therapy attempted will produce mentally, and probably physically damaged asexuals with personalities that would make roid rage look like narcolepsy, with mommy and daddy wishing they could trade him back in for a nice homo. As I’ve said, Mother Nature does not like being fucked with, and you don’t have to read much history to understand what she has the human mind do within every attempt at utopia.

    In short, they will attempt it eventually, and they will fail. Nature is obviously determined about our presence. But what are we going to do? Are we going to sit around while by no means all, but some scientists contemplate such a holocaust?

    One more point. At the end of World War 2 when antibiotics came in to wide use there was something like 2 billion people in the world. That’s after 100,000 years. Only 60 years later, we’re closing in on 7 billion! Antibiotics proved to be a double-edged sword. I have read that 11 billion is the point that our species becomes unsustainable on this planet. After that point, innate biological processes kick in in the brain, much as is seen in other species, and then we literally go for each others throats automatically on a mass scale. I think as we approach that, our presence in the world will seem among the least of its problems.

    Only natural because, let’s face it, we’re one of the world’s greatest benefits. LOL

  • schlukitz

    I am what I am…and that requires no explanation.

    If I must explain to those who question my gayness, then I demand that they explain their straightness to me.

    Fair is fair!

  • romeo

    @ Ray #38: As has been noted on this thread, you’re situation is not exactly rare, but both twins being gay is far more common. Is there a right-handed/ left-handed difference between the two of you? And there are other differences between identical twins.

    As has been noted over and over since the real examination of society began with the Enlightenment, conservative traditionalists are dead wrong about the benefits their values offer to society. Those values only benefit a few, which is the agenda, and the rest are left enslaved and suppressed. That’s not what America is supposed to be all about. Freedom generates more cash, which is what America is really all about. Right-wingers need to learn how to be good Americans, especially after destroying the country’s economy the way they have done. World markets are diving again today. We have a long, hard road digging ourselves out of the infantile mess the conservatives stuck us with.

    They don’t know shit about anything. They can just sit down and shut up.

  • Attmay

    @39 Romeo:

    If the planet becomes unsustainable after the population reaches 11 billion, then we need homosexuality to be not only tolerated but encouraged to keep the population down.

    Breeders, look me in the eye and tell me uncontrolled heterosexuality is a benefit to society.

  • Glasser

    Soul choice.

  • Jaxs

    This is bunk. There is no evidence here. The only purpose of this video segment is to assert that gay men are “broken” straights. They went a very long way just to NOT say that their brain scans appear to be more or less “identical”.

    If this were somehow to be true, then the evidence would be overwhelming during autopsies – which it is not.

  • biANDnotConfused

    my opinion is that you can not be born gay and identical twins are NOT i repeat are not 100% identical .. that being said one has nothing to do with the other .. it is a choice to become gay by how your raised, the persons environment and things socially growing up can lead up to that .. and everything does not need an answer thats why theres so much controversy towards gays .. i even got into an argument with a lesbian saying she “was born” that way .. i believe all things, even small, always lead up to something major like becoming gay .. i myself am leading towards that .. its not just a preference either or that im 21 and young wanting different but its my opinion on being born gay NOT TRUE

  • biANDnotConfused

    **the lesbian said she was “born gay”** typo

  • Ritorna

    Isn’t it wonderful? Another study designed to determine what went wrong to make little Tommy gay. Loved the shot of the twins as the narrator said, “…and why one gets a disease while the other does not”. What a load of crap.

  • JJ


  • JJ

    Just one more way of trying to discriminate against LGBT of color humans like they use to come up with everything rediculus like black slaves have no souls to discriminate against blacks during slavery and Real Native Alaskans with Jim Crow laws and Real Native Americans to take their land-Oh they are savage so that is why we are justifying killing off and discriminating against real Native Americans and Real Native American Two spirited first nations LGBT of color humans to take their land.

  • Ivy

    Identical twins only look alike, they don’t necessarily like the same things, or think identically. So why should the orientation be identical. Pfft!

  • what about me

    OK that’s great an all that testosterone affects male sexual orientation but what about women?

    im gay while my identical twin(mirror image)sister is straight.
    im left handed shes right handed

    so i get that epigenetics plays a role but is being gay supposed to be dominant or more of a recessive trait?
    and since genetics is not the only component that plays a role in a persons, what environmental factor can cause it?
    i mean we were both raised in a catholic anti-gay family

    i wonder if there are any studies on mirror image twins and sexual orientation if there are more straight/gay pairs than gay/gay pairs.

  • jason

    When they refer to twins as gay and straight, are they referring to orientation or behavior? It’s entirely possible that both twins are bisexual in orientation but one behaves in only a gay way, the other in only a straight way. Behavior is the nett product of orientation plus environment.

  • Homophobeslayer

    No. 45 your dead right that is your oppinion …so while my gay friends and I believe and yes know that we were all born gay and love it proud of it you just keep telling your self it’s a choice because it is 2011 I am 23 after all the shit I have been through I damn well know it wasn’t for me a choice to be homosexual i’m not going to let someone’s anyone’s hatred ,ignorence, bigotry for me and my gay and lesbian brother’s and sister’s cause me to say o my god I chose to be this way I should just stop being homosexual and be heterosexual so they will stop spiritually , phisically ‘ emotionally beating the hell out of me I will eat, pray , love thank Jesus for life another chance every day I get to better it and someone elses however… I will beat the hell out of a homophobic m####f###a trying to hurt me or the one’s I love before I allow him to have me saying on an awsome blog like this one that I chose to be hated by much of the world that people like me in times past who faught for GAY RIGHTS AND WERE GAY chose to be hated by much of the world hell no here is my oppinion child being gay is a natrual part of the fabric of humanity a gift from GOD and if it were a choice then being straight would be and it is not guess what there is a cure for ignorence and there is a cure for stupidity and yes there it is called edgucation knowledge is power however as long as we LIE AND AGREE WITH THOSE DAMN LIERS THAT HOMOSEXUALITY IS A ”CHOICE” we only help them with their I will keep listening to smart bisexual gay and lesbien people Jesus and that is why I am still here fighting this equality war and when we do win all the way those who just knew it was a choice you can just choose to be straight while we party enjoy our lives cept it 100 and are still getting , building ,haveing wonderful a wonderful life since I know it isn’t a chioice go ahead and keep saying it is those of you that do I know from my own personal experiences that it isn’t that is what set’s me apart from bisexual men love them and gay men love them too that say it is a choice maybe for you it was a choice that is your story many others are very different so it offend’s me and many other gay who have been through earthly hell when you say and I AM READING BETWEEN THE LINES WE CHOSE IT MY GOD THAT MAKES ME WANT TO FIGHT !!!!!!!!

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