Identical twin studies prove homosexuality is not genetic


By Mark Ellis

Dr. Neil Whitehead
Dr. Neil Whitehead

Eight major studies of identical twins in Australia, the U.S., and Scandinavia during the last two decades all arrive at the same conclusion: gays were not born that way.

“At best genetics is a minor factor,” says Dr. Neil Whitehead, PhD. Whitehead worked for the New Zealand government as a scientific researcher for 24 years, then spent four years working for the United Nations and International Atomic Energy Agency. Most recently, he serves as a consultant to Japanese universities about the effects of radiation exposure. His PhD is in biochemistry and statistics.

Identical twins have the same genes or DNA. They are nurtured in equal prenatal conditions.  If homosexuality is caused by genetics or prenatal conditions and one twin is gay, the co-twin should also be gay.

“Because they have identical DNA, it ought to be 100%,” Dr. Whitehead notes. But the studies reveal something else. “If an identical twin has same-sex attraction the chances the co-twin has it are only about 11% for men and 14% for women.”

Because identical twins are always genetically identical, homosexuality cannot be genetically dictated. “No-one is born gay,” he notes. “The predominant things that create homosexuality in one identical twin and not in the other have to be post-birth factors.”

Dr. Whitehead believes same-sex attraction (SSA) is caused by “non-shared factors,”  things happening to one twin but not the other, or a personal response to an event by one of the twins and not the other.

For example, one twin might have exposure to pornography or sexual abuse, but not the other.  One twin may interpret and respond to their family or classroom environment differently than the other. “These individual and idiosyncratic responses to random events and to common environmental factors predominate,” he says.

The first very large, reliable study of identical twins was conducted in Australia in 1991, followed by a large U.S. study about 1997. Then Australia and the U.S. conducted more twin studies in 2000, followed by several studies in Scandinavia, according to Dr. Whitehead.

“Twin registers are the foundation of modern twin studies. They are now very large, and exist in many countries. A gigantic European twin register with a projected 600,000 members is being organized, but one of the largest in use is in Australia, with more than 25,000 twins on the books.”

A significant twin study among adolescents shows an even weaker genetic correlation. In 2002 Bearman and Brueckner studied tens of thousands of adolescent students in the U.S.  The same-sex attraction concordance between identical twins was only 7.7% for males and 5.3% for females—lower than the 11% and 14% in the Australian study by Bailey et al conducted in 2000.

In the identical twin studies, Dr. Whitehead has been struck by how fluid and changeable sexual identity can be.

“Neutral academic surveys show there is substantial change. About half of the homosexual/bisexual population (in a non-therapeutic environment) moves towards heterosexuality over a lifetime. About 3% of the present heterosexual population once firmly believed themselves to be homosexual or bisexual.”

“Sexual orientation is not set in concrete,” he notes.

Even more remarkable, most of the changes occur without counseling or therapy. “These changes are not therapeutically induced, but happen ‘naturally’ in life, some very quickly,” Dr. Whitehead observes. “Most changes in sexual orientation are towards exclusive heterosexuality.”

Numbers of people who have changed towards exclusive heterosexuality are greater than current numbers of bisexuals and homosexuals combined. In other words, ex-gays outnumber actual gays.

The fluidity is even more pronounced among adolescents, as Bearman and Brueckner’s study demonstrated. “They found that from 16 to 17-years-old, if a person had a romantic attraction to the same sex, almost all had switched one year later.”

“The authors were pro-gay and they commented that the only stability was among the heterosexuals, who stayed the same year after year. Adolescents are a special case—generally changing their attractions from year to year.”

Still, many misconceptions persist in the popular culture. Namely, that homosexuality is genetic – so hard-wired into one’s identity that it can’t be changed. “The academics who work in the field are not happy with the portrayals by the media on the subject,” Dr. Whitehead notes. “But they prefer to stick with their academic research and not get involved in the activist side.”

Even though same-sex attraction is not genetic, Dr. Whitehead disagrees with those who contend that homosexuals “choose” their orientation. “There can be little informed, responsible choice involved if first attraction is about age 10,” he notes. “At that age no-one chooses lifetime sexual orientation or lifestyle in any usual sense. SSA is discovered to exist in oneself rather than chosen.”


Dr. Neil Whitehead is author of the book My Genes Made Me Do It – a scientific look at sexual orientation (1999/USA; revised 2nd edition, 2010) and over 140 published scientific papers. The book is available as a free download. It takes account of research undertaken between 2000 – 2012, which strengthens the book’s original conclusions. The book takes a position based on an objective, orthodox and comprehensive 20+-year review of more than 10,000 scientific papers and publications on homosexuality. Dr Whitehead has lived and worked in New Zealand, India, the United States, France, Japan and Afghanistan.



  1. As a (celibate) gay Catholic I find these sorts of articles trying to prove that I chose to be gay rather than me just being gay really upsetting. I have always fancied males, as young as four I knew I liked boys and not girls. At about ten I started to think about boys in a sexual way as my friends did about girls. I grew up in a military family where homosexuality was not just unacceptable, it was downright loathed. Yet there I was, supposedly choosing to be gay in an environment that would have tortured me had they know what I was. Just bonkers suggesting I chose to be gay, why would I choose to be at odds with my world, my family and my friends and all the angst that comes with that. I know people whose sexuality is very fluid, and in both directions. I accept the teachings of the Church about homosexuality and homosexual practice, it makes sense, but the response I receive from these articles is that in return the Church sees me as a a sort of moral mutant to be explained away. I am getting pretty tired of being a pariah in the community that I have served faithfully (full time) for the last 20 years, often without pay or thanks. I get the impression you “purists” are looking for a neat little community of believers without any of the messy complications that life can throw out at us. Scripture and history attest to a very different reality and one that will leave you behind if you don’t just grow up about the moral maze all of us must walk in the 21st century. There are a few simple points a person must be aware of today. 1. If you say you are a Catholic, BE a Catholic. 2. You can defend the Faith without disparaging certain members of the Faithful. 3. Accept that people come in all shapes, sizes and hues, and that as long as they practice the Faith in accordance with the mind of the Church and not their own interpretations, then don’t try to explain them away or disparage them with shoddy studies like this one. A Church without gays might not be the oasis that you think it might be once they’ve been explained away or “cured”.

    • Dear Edward,
      I have great admiration for what you have written. I don’t view you as a moral mutant, not do I consider myself morally superior. My struggles with sin on a daily basis are no different from your own. There is an important point that Dr. Whitehead made that I will now add to the article, based on what you have written. He made the point that no one chooses same-sex attraction. Forgive me for this oversight, dear brother. The fact that you are maintaining celibacy and standing for truth deserves high praise. I pray you will find healing and wholeness in Christ.
      Mark Ellis

      • Hi, Edward,

        How wonderful it is that you are sharing this and living such a holy life! I don’t think homosexuality is genetic, but I also don’t necessarily think it is a choice. I do think that forbidding any type of therapy in regards to same sex attraction is a travesty, because there are people who have same sex attraction that is from factors beyond their control, but therapy may help them to at least understand themselves better. I just think that going overboard in any direction is not helpful to anyone. I hope when you consider these informational articles in the future, you see them for what they are…just information. No blame is intended. Sometimes, however, when this attraction is due to abuse or other factors, information like this may help THAT person to know that their attraction isn’t due to something totally out of their control, like genetics. Hope that makes some sense. There are two extreme ends; totally out of anyone’s control (genetic) and totally due to societal influences (formed) and I don’t think either applies or is helpful for bringing about understanding.

        Please keep this in mind: God can heal all hurts. I was a very damaged person for many years. It took me a very long time to realize that it was impossible for me to feel love from others and what happened to me to cause this. We all have our crosses to bear, and only the strongest are given the big, heavy ones. I had asked God to heal this in me….to stop me from feeling so needy all the time. He did heal me in His time. He will lighten your burden if you ask. God bless you and you will be in my prayers!

        • Homosexuality is only tied to genetics as deeply as one’s own sin nature. If a person is born a homosexual, then there are also those born as murderers, liars, thieves, adulterers… Not because of genetics, but because of sin. One can only be redeemed from this bondage of sin by faith in Christ’s vicarious atonement and bodily resurrection. He is RISEN! And therein is hope.

          • Donna, I hope the only person you’re choosing to have sex with is your husband. If you haven’t met him yet, then you should still be choosing to only have sex with him, waiting for the day you’re united in holy matrimony.

        • Edward E wrote:

          “As a (celibate) gay Catholic I find these sorts of articles trying to prove that I chose to be gay rather than me just being gay really upsetting.”

          But the author said:

          “At that age [10] no-one chooses lifetime sexual orientation or lifestyle in any usual sense. SSA is discovered to exist in oneself rather than chosen.”

          In other words, you are distressed about something that I don’t believe the author stated.

          • Well said Dave – and Edward, I think you’re equating non-genetic too strongly to choosing sexual attraction. I think the article is pointing out that something environmental could have happened to cause same sex attraction – thus just because same sex attraction is not genetic a person still may come across an environmental event that brings this sort of thing about without a person choosing this to happen.

            Your strength is admirable Edward – I admit, I would not have had the strength you have displayed. May the Lord be with you.

            Sincerely – Billy

        • Very interesting study! As a young person I would always hear persons talking about their homosexual tendencies as genetic, after taking genetics in university I decided that was simply incorrect! Thank you for sharing this study. I am going to repost it on my lifestyle website or young adults!

        • And what about those with “feelings” for children, animals, dead people, inanimate objects?! ALL choices (obviously, bad ones). The word “abomination” is in the scriptures for a reason. Others might call it “sexual preference,” or “curiosity.” God allowed the destruction of the Canaanite nations for such “curiosities.” How many sexually transmitted diseases are the result of sexual “curiosities!”

          • I agree, Ernest. Regardless of your ‘preferences’ the ‘choice/ choosing’ is NOT about ‘thoughts / feelings’, it’s about your actual, physical response. I can sit & THINK all day about armed-robbery, but until I get up & go COMMIT (act-out, make manifest, bring to fruition, etc.) armed-robbery, then no crime has been done. And further more lets simply call homosexuality what it is- a fetish. If you ask 10 different heterosexual men what they find sexually attractive in a woman, your apt to get 10 (or even more) different answers. Everyone has their preferences (fetishes). Are not pedophiles, necrophiliacs, & those who practice bestiality merely responding to their sexual preferences (fetishes)? Of course they are. So the question doesn’t lie in CHOICE alone, but rather in the CHOSEN RESPONSE. In closing, let me just ask this, if a kleptomaniac were to get caught stealing from a sodomite, kiddie-porn perv or a ‘sheep-lover’ & his/her only reasoning (excuse) for the theft is, “Well, I’m a kleptomaniac. I can’t help it. You see, I was just BORN THIS WAY.” Is that answer gonna’ fly with the said victim? Now, I’m not a gambling man, but I’ve got a nickel in my pocket that says, “No. Absolutely NOT!” Homos should take heed- that same EXCUSE is NOT gonna’ fly in any man-made court of law. How much LESS is it gonna’ fly on Judgement Day before the Throne Of Christ when He has already deemed this behavior not only an ABOMINATION, but a DIRECT ACT OF REBELLION against the Kingdom Of Heaven because it was carried-out, by their own admittance, as a ‘Willful, self-chosen act’? Practicing-homos will be without EXCUSE! Amen.

        • NB: “Identical twins have the same genes or DNA. They are nurtured in equal prenatal conditions. If heterosexuality is caused by genetics or prenatal conditions and one twin is straight, the co-twin should also be straight.”

          This study is no good. I would not do such speculations based on that.

          • What you appear to be saying is not proof against the study, but actually gives merit and agrees with the conclusions the studies all came to: sexual heterosexuality or homosexuality is not determined by genetics. Genetics has nothing to do with determining a person as born “that way”..

      • In the biological world thoughts, emotions, desires & actions agree with biological design. It is a state of being whole. Being whole is what causes us to exist & ensures that there will be a future.

        In contrast, embracing the Homosexual Lifestyle causes the inner urges & sexual desires of a person to conflict & contradict their outer form, making a person at-odds with themselves & divided from their own biology. Desires are detached from biology. It is a Lifestyle that prevents existence.

        These are really 2 different modes of being and it is important to because each mode of being creates a completely different societal structure, including different legal and political systems.

        The union between a man & a woman creates an extended family organized by family roles for the purpose of making the future,
        so likewise, the union between those in the Homosexual Lifestyle create a structure to fit its purpose:
        a society with places for two – Partner 1 & Partner 2 –

        An easy way to understand the difference between the biological family & the Homosexual Lifestyle is to see them as 2 different types of organizations. Because of their 2 different purposes they’re set up differently.

        The limited-member society of the Homosexual Ideology is one without reference to children or family positions. It lacks the structure to provide an environment to raise children,
        to create a stable society, or to produce the future.

        So it ends up being more than just a individual issue. It has far-reaching ramifications with the Homosexual Lifestyle being given legal rights.

        The issue at hand is about society having a stable structure in place so there can be a future. The Homosexual Ideology simply does not provide that.

    • Hey Chris. Read the last part of this article again. From your response, it is clear that you did not understand that last part, which says:

      “…Even though same-sex attraction is not genetic, Dr. Whitehead disagrees with those who content that homosexuals “choose” their orientation. “There can be little informed, responsible choice involved if first attraction is about age 10,” he notes. “At that age no-one chooses lifetime sexual orientation or lifestyle in any usual sense. SSA is discovered to exist in oneself rather than chosen.”

      Thus, if you read carefully, you will note that nowhere does it say that being gay is a choice. It is the same in perceptions of spirituality: one has to be careful not to throw the baby out with the bathwater.

      I wish you good luck with finding the difference between the two.

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    • The article does NOT reflect that you “chose” the homosexual lifestyle.
      Read the last paragraph (19) again.

    • The last paragraph actually states:
      “Even though same-sex attraction is not genetic, Dr. Whitehead disagrees with those who content that homosexuals “choose” their orientation. “There can be little informed, responsible choice involved if first attraction is about age 10,” he notes. “At that age no-one chooses lifetime sexual orientation or lifestyle in any usual sense. SSA is discovered to exist in oneself rather than chosen.” Reread the last sentence. Maybe I am not understanding. He says SSA exits in oneself rather than chosen….. I did not get from the article that was trying to convince people anything other than we are not born gay.

    • Dear Edward,

      I don’t think Dr. Neil Whitehead is trying to prove that gay is by choices. He only concludes “not genetic”.

      There is still huge room between choice and not genetic, isn’t it? If that can be discovered and truth be revealed, it will be the liberation for all of us, including homosexual and heterosexual in my humble opinion.

  2. I take what he says on face value. However, I think that it is important that these studies be sourced, and in addition, to give citations of corroborating professionals who have come to the same conclusion from these studies.
    Any scientific data needs peer review to lend it credibility. I’m not saying that it doesn’t exist. I just don’t know. But for me, as someone trained in science, one should never just take the word of one person’s findings.
    The fact that Dr. Whitehead is a Christian means that he is going to be seen as peddling an agenda by those who may not like the implications of this news.
    We have nothing to fear from the truth. But it needs to be done the right way.

      • How utterly presumptuous amd Imbecile of you to think that a news source like GodReports would only interview religious people!! This man is a SCIENTIST and like Mr Ellis said ( a professional reporter) his religious beliefs never came up in the interview in FACT the study (One of EIGHT count them) says it was Neutral…you probably think they walk around w/ a cross and holy water in thier pockets….Get a CLUE!!!

  3. Who cares – if you spent this same time caring for the poor or children of addictions – you might actually do something that helps humanity.

  4. And if you bring the truth about this issue to the forefront, to challenge the political dogma that is steamrolling the rising generation into hard core indoctrination that they are in eternal bondage to their dysfunctional desires, and denying them the option to overcome such attraction if they would choose to, you are profoundly helping humanity.

  5. ..This is interesting…if it is not genetic and is not a choice what is it?….
    ..any thoughts on that?… Some new information ?

    Religiously: “if god places the burden he gives us the grace to carry it.”

      • The feelings of opposite gender attraction are not a choice, but what you do with the feelings is a choice.

      • The feelings of same sex attraction are a result of rejecting one’s own biological design, not a choice about attraction. At its core, the desires that cause the Homosexual lifestyle are ones that first make a person reject their own biology and disconnect from themselves. The attraction for same sex is a later result of that.

    • It might be a chosen choice in some cases. Some might just try it from sexual curiosity. I have read about such a case. In other cases it might be the result of external psychological effects. These might slowly accumulate from early childhood – and then the individual do not even recognize them and think that “he always felt so”. This might be so with transsexuality, too. And the external effect might be more manifest – eg. in cases of sexual child abuse or seducing a teenager into same sex relationship. In these latter cases the homosexual desire might be only partly a choice or not at all – thus it is the result of a psychological distortion coming from external causes. It cannot be excluded that some homosexuals also had a genetic distortion which caused a troubled sexual identity for them. Not directly homosexuality but some biological or psychological feature because of which they proved to be unsuccessful in their social environment or in couples’ relationships. And then they felt they are strange somehow and so they thought that they are not straight.

  6. There was a study done on soy which found, soy causes much hormonal change. -and homosexuality. It could cause a lot of homone problems which are not combined with sexuality. Babies fed a soy formula could affect some and not others—twins. Which was started in the late 50’s. Search
    Also it must be remembered everyone has to go through a crucifixation on this earth and if they accept it , they are commuting their sentence of purgatory. Losiing a child, born with a handicap, dying a painful death, breakup of marriage, children who go astray—-you name it, all sorts of pain. Jesus said to the holy women who were crying for him on the way to calvary “do not cry for me, but for yourselves and your children” telling us of our crucifixtion also. He was showing us how to do it, with acceptance.

    • Dear Phyllis, their is no such thing as purgatory, if you actually understood what the purgatory belief really means, you could not be a Christian and belief in purgatory. Let me explain, to believe in purgatory means that you can at a later date, work out your own salvation, this is heresy and nowhere found in God’s word. To actually believe this you call Jesus a liar and the Bible corrupt. Your saying that Jesus didn’t do enough on the cross, that he didn’t pay for all of our sins, this amounts to blasphemy or shear disbelief in the Gospel message. YOU are not a perfect sacrifice, “no one shall be saved by works lest any man boast, but this is a gift from God, that we have been saved by grace through faith alone.” You are denying Jesus as the only way to GOD and don’t even know it like other catholics. I was raised as a typical catholic, until one day I seen a change in my father forever, that caused curiosity in me to actually read Gods word for myself. I found half of the catholic teachings to be nonsense, and more or less when Constantine legalized Christianity in the 4th century he made it palatable for romans by combining Christianity with roman paganism. IN closing, if you try to work out your own sins in an imaginary purgatory, you will spend eternity in hell for rejecting Jesus’ perfect finishing work upon the cross. It’s not about YOU or your performance as a human being, that’s called self righteousness, its about his perfect love/gift of salvation upon the cross. Paul told us to put away silly traditions of men/religion and seek the truth in Christ alone. And don’t quote me phil. 2:12 the scripture of working out our salvation, that has nothing to do with us being able to gain salvation by works, but rather is about receiving the free gift of salvation, as many reject it. Remember it says to work out their salvation, not to work for their salvation. Hence it is unattainable through works, its his work and performance upon the cross, nothing of ours, God calls our works rags.

  7. There should be a forward slash between the 12 and the 39253 in the comment just before t his one instead of t he dash

  8. He said homosexuality is not a choice and is not genetic but is a predisposition and preference due to internalized (and subconscious) perceptions and interpretations of post birth experiences. My wife and I discussed this and we understand it when we aligned it to our own predispositions and preferences; she prefers black men (she is white) and I have a fetish for women’s feet. Do we choose those things? No; we just act upon our preferences. So we know it is not a choice but instead an acting upon a subconscious preference.
    One thing to note however, homosexuality is not like any other demographic moniker. You know nothing about a so called “black” person other that his skin is dark; not his intellect, his education, his wealth, his social status, his health, his personal background, his criminal history, his speaking pattern…nothing. The same is said for any demographic – handicaps, American Indians, Jews, Brazilians, Canadians, “white” people, Japanese…no one.
    Homosexuals, by definition, are the only group that has an identity that is known; they engage in sexual activity with the same gender. (Edward E knows this which is why he self disclosed that he is “celibate.”) That distinction is what makes them different from every other group and why they cannot claim to be eligible for “civil” rights like women’s suffrage at the turn of the century or so called “blacks” in the ’60s. If someone knows what you do, disagrees with what you do, and by definition you cannot deny it, they have a right (not wrong or right) to separate themselves from you. A pedophile, an adulterer (Tiger Woods still catches a lot of flack), and a smoker are all definitions based on actions and can and will be judged as such.
    I am not judging or bringing in religion to my own post (others will do that for me I am sure.) I am just bringing in a different perspective and information that may be useful.

    • A different perspective that is flawed and still waiting for the useful information. “You know nothing about a so called “black” person other that his skin is dark; not his intellect, his education, his wealth, his social status, his health, his personal background, his criminal history, his speaking pattern…nothing.” The same goes for homosexuals. The only thing you “know” is that they are attracted to the same sex. “Homosexuals, by definition, are the only group that has an identity that is known; they engage in sexual activity with the same gender.” So sex is the only measure by which to define a persons identity? “they cannot claim to be eligible for “civil” rights”. I guess the constitution only applies to straight people. Damn, and here I thought all men were created equal and that there was supposed to be equal protections under the law.

  9. I wish there’s a like button on comments so I could’ve liked so many comments here.

    I don’t believe this study. There’s no such thing as identical twins and there genes are totally identical in every aspect. Having said that, being gay is not a choice because if it was, every homosexuals have chosen not to be homosexual. Plain and simple and easy to understand.

    • Respectfully, to say there is no such thing as identical twins, with identical DNA, is factually incorrect. This is the definition of an identical twin and it is what makes these studies so authoritative and conclusive. Dr. Whitehead did not say anyone chooses their feelings of same-sex attraction. However, what you do with the feelings — whether to act on them or not act on them — is a choice.

  10. In the 1990’s, when the ‘Gay’ community learned that the son of Phyllis Schlafly, a conservative and anti-gay activist, had a son who was a homosexual, Queer Week magazine rushed to interview him. They first asked him if he opposed his mother’s anti-gay activities. He told the magazine he loved his mother and supported her right to practice her First Amendment rights. They then asked him if he believed that people we born homosexuals. He told them that he believed that people are born with an inclination and that we are able to choose what to do with that inclination.

  11. The notion that decisions are always rational is a misnomer advocated by the author. A 10 year old may make a decision to smoke or ssa by emotional fiat. That is what is known as an irrational choice. It is whim driven and is not something well thought out with identifying objectives, listing alternatives, considering adverse consequences, etc. This aspect of decision making needs to be integrated into the study of homosexuality.

  12. Given that Edward, Chris (near the top of the comments), and others, agree with Dr. Whitehead that homosexuality, while not genetic, is still not a chosen lifestyle; what would you say that factor is then? What would you say that is sooo deep in a person as to cause them to yearn for the sexual love of fellow male, or “fellow” female?

    I would like to proffer at least one possibility… that which involves the spiritual realm. I’m speaking not only of our own soulish or spiritual selves…… but how we are affected by what the Bible terms the powers of the prince of the air. This involves spiritual beings which have set themselves in direct opposition to God and His plan for His creation. It is these fallen angelic beings who can insert thoughts and feelings into a person’s mind so deeply that it’s almost as if it was the person’s own thoughts. I believe this has something to do with those who have desires or feelings dating back to their early years. Read the scriptures yourselves to see if what i said has plausibility.

    One other thing, there are many like Dennis Jernigan (worship singer) who have that early life experience and still were able to get married to an opposite gender person.

  13. It is evident that there are those who are not attracted to the opposite sex.
    Jesus addressed those people in Matthew 13, immediately following His classic treatise against divorce:

    “All cannot accept this saying, but only those to whom it has been given: For there are eunuchs who were born thus from their mother’s womb, and there are eunuchs who were made eunuchs by men, and there are eunuchs who have made themselves eunuchs for the kingdom of heaven’s sake. He who is able to accept it, let him accept it.”

    There is a difference between proclivity and activity.
    It is irrelevant whether someone is genetically oriented toward homosexuality, they are commanded to abstain.

    Therefore, anyone who does not want to marry the opposite sex is free to serve Christ as a celibate Christian, even as Edward has determined to do.

  14. if Dr. Neil Whitehead was a real scientist, he would have offered his findings and its data for peer review and publication, not have it only available for free download. He is not playing by the rule of science.

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