What Causes Homosexuality?

A recent discussion in one of this blog’s comboxes veered off into the old nature-or-nurture/chicken-or-egg question about homosexuality.

The question: Is same-sex attraction the result of the individual’s genetic make-up, or it is the result of the environment in which they were raised?

Based entirely on a crude anthropology, I would guess that there must be a genetic component to homosexuality. Why else would same-sex attraction show up in most, if not all, societies and epochs of recorded history? The ways in which children are raised vary quite a bit from one time in history — and one culture or society — to the next.

So far as I know there is no way of ascertaining if certain cultures or methods of child-rearing have historically resulted in a higher proportion of homosexuals among their citizens. But it does seem — again, this is crude anthropology — to be pretty much ubiquitous.

That raises the question: Is there a “gay” gene somewhere on our chromosomes, like the brca genes that predispose people to breast cancer? The answer, at least for now, is that no one knows.

What we do know is — like my “anthropological” assessment — guesswork based on derivation. Perhaps the most interesting guesswork in this field comes from the so-called “twin studies.”

When I did a quick google, I found that there is more than one study attempting to correlate same-sex attraction with heredity by looking at identical/fraternal/non-twins . It turns out that these studies seem to indicate that there may be a genetic component in same-sex attraction, but it does not appear to be definitive.

Of course, there’s no way to know what this genetic component might be. Is it one gene, or two, or a combination of genes? It’s possible, say, that identical twins who are both homosexual might have inherited a combination of genes that made this outcome certain for them, while other pairs of identical twins where one is homosexual and the other is not might only have inherited one or two genes of this same combination, thus injecting the factor of environment into their sexual fates.

On the other hand, it made be that there is a set of inheritable factors that predispose a person toward homosexuality, but that same sex attraction develops only when this genetic make-up coincides with an environment that pushes the individual in this direction.

Another factor that some of the scientists who did these studies have raised is the environment in the womb. How did the hormonal input to the baby from the mother affect its development? Perhaps the “environment” in question is not so much psycho-social as it is biological.

All this is to say that we don’t know what conditions or factors lead people to experience same-sex attraction as a definitive sexual orientation.

I have seen, based entirely on being around gay men, that there are individuals who, though they experience same-sex attraction and define themselves (at least internally) as homosexual, are quite capable of functioning sexually as heterosexuals. They can and do marry women and hide their homosexuality. On the other hand, I have known gay men who simply could not do this. Their same-sex attraction was so profound that it precluded them even attempting to marry and “pass” as heterosexual.

I only mention this because it raises, at least to me, the thought that same-sex attraction may not be an all or nothing orientation for many people. It may, in fact, be more a matter of degree, at least for some.

None of the things I’ve mentioned here affect the arguments for preserving traditional marriage. I don’t see supporting traditional marriage as a denial of either the reality or the humanity of gay people.

It is just simply that men and women together are the people who create other people. No matter how much sympathy I have for gay people, no matter how completely I agree with many of their concerns, the fact is that homosexual unions are sterile. They do not make other people.

I am well aware that many homosexuals have resorted to manipulations of biology to have children. But these manipulations lead directly to the exploitation and commodification of both women and human life. They are, in themselves, misogynistic and evil.

Gay sex does not make people. Traditional marriage between a man and woman produces children and is the best cradle for nurturing those children to responsible and productive adults who can have children of their own and nurture them. Redefining marriage in strictly social terms that ignore this basic function of marriage is destructive to society as a whole. I am certain that gay marriage is the road to nowhere for our society.

On the other hand, I am equally certain that homosexuality is a fact of human existence. I do not think that we can set aside the reality of homosexuality, or the just claims for civil and human rights of gay people.

You can find one of the studies Gay is Not All in the Genes which was published in Science in 2008. I chose it because of the reputation of the publication and its relatively recent origin. There are many other studies out there, if you want to look.

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  • SteveP

    Rebecca Hamilton: Please allow me to apologize for the tone of the comments you deemed in need of deletion. While I agree with your post here I am puzzled as to why the origin of a self-identified facet of a person is significant. That is, we are material and immaterial beings – we will be influenced by biology and environment. It seems to me that the end of this logic is that any behavior can be then declared as needing protection as a class.
    However, I’ll cease using the comments on your blog in fighting what I consider the “gay brand.” The brand insidiously suppresses the fact that many homosexual males have done great harm to others, especially younger males.
    May the grace and peace of our Lord Jesus Christ be with you now and always.

    • Bill S

      “The brand insidiously suppresses the fact that many homosexual males have done great harm to others, especially younger males.”

      It hardly matters whether you classify an abuser as homo, hetero, bi, etc. An abuser, by his very definition, does things that are harmful to others. When you judge an action, the first question you should ask is what harm does the action do to others. If it harms others, it is much worse than if it doesn’t and may even be illegal.

      I don’t know exactly what you are referring to when you say the gay brand, but whatever that is, if it applies to consentual acts that harm no one, then it should be of no concern to you or religious authorities.

      It is wrong (and maybe evil, for lack of a better word) to condemn all homosexuals due to the actions of sexual abusers. You should know that.

      • Ted Seeber

        What is consensual about a gay pride parade forced into your neighborhood?

        • Mike

          LOL good point, if not a cheeky one.

  • Gregory Peterson

    Sex in humans is primarily about bonding, as you would expect from an intensely social species. We don’t just care for our own children, but for all children…as well as for our infirmed and elderly. Encouraging stable relationships, “procreative” or not, is good for all children.

  • Sus

    Rebecca, this is a great post. I’ve read a little bit about estrogen levels during pregnancy. One study claimed that that moms who have children in their late 30s have a higher chance of having a gay male child. Also the more pregnancies you have, your body produces less estrogen. I looked for the link but couldn’t find it.

    I agree with you that gay marriage is the road to nowhere as far as creating children. There are exceptions but in general most won’t go that route. It’s up to us to keep the population going.

    If I see an example of a loving and faithful.relationship, I will point it out to my kids – gay or straight. I need all the examples I can get to counteract all the nonsense.

  • http://www.flickr.com/photos/8601342@N03/ Gregory Peterson

    Not to mention that “homosexuality” is a fuzzy social construct, which like “race,” has been loaded down with self serving definitions, long discredited science and relentless scapegoating. I know lots of Gay and Lesbian people, but not one self identified “homosexual.” Causation of one’s primary sexual orientation, when it comes to justice, the Golden Rule and equality under the law, is not applicable, except when it’s used to discriminate and oppress. That’s why in my state, sexual orientations puts you in become a protected class. Causation of sexual orientations should be merely interesting.

  • Bill S

    ” I am certain that gay marriage is the road to nowhere for our society. ”

    What do sociologists have to say about gay marriage? Even if psychologists support it, it might still be bad for society.

    I no longer look to religious leaders to determine what is best for society. They do not have a good track record.

    • Ted Seeber

      I don’t know about sociologists- but I do know what certain evolutionary biologists have been saying- that homosexuality in males expresses itself as hyper heterosexuality for females, and thus, you might say that gay marriage is the expression of genetic feminism.

  • mark

    What if science discovers a child abuser gene or one which makes someone prone to theft or any of the other deadly sins? Catholic teaching tells us we are all born in sin and in need of salvation. By the grace of God, we have hope of using this gift and the power of the Holy Spirit to overcome the temptation of the splinter in our heel, be it by gene or other means. Natural law is also part of Gods plan and when we deviate from that plan, we are certain it will never work out. This is true when we deny God His right to create life in the manner He gave us as man and woman or if we think we have a right to children when for whatever reason God has denied us children. We have abundant gifts as children of God and joy when we surrender our will to accept what He has decided for us. Those who have attraction to the same sex are called to celibacy as are those not blessed in the sacrament of marriage. We all need to rediscover the word sacrifice not only as Catholics, but also as Americans. We fail to be one nation UNDER God at our own peril.

    • pagansister

      So to you, homosexuality is a defect that should be corrected, if indeed there is any proof of the hormone environment in the womb or perhaps a gene is detected. If we all are “children” of a god, who was supposed to have “created” all people then how is it that those who worship that deity can’t be as loving and ACCEPTING of the whole homosexual person as well and not just those who “don’t act” sexually on that attraction?

      • Ted Seeber

        It is my hope that good pro-life Catholics will be speaking out, in such a situation, for the right of homosexuals to be born; because I can easily see a pre-natal test for homosexuality turn into a genocide of abortion, just as it has for downs syndrome people.

  • pagansister

    What causes homosexuality? Does it really matter?

    • callmeart

      If the cause were found and medical science could effect a change to heterosexuality [such as artificially altering the hormonal environment in the womb], fewer people would face confusion and bullying, and fewer fervently religious people would face a life of celibacy.

      • Bob

        Wow, that is chilling.

    • Sus

      I think it matters because every time homosexuality comes up on these blogs, people say that homosexuals are more likely to sexually abuse children. That lie has to be debunked once and for all.

      • Ted Seeber

        It is a lie born out of experience, if it is a lie. My entire formative experience with gays was that they were sexually agressive- the recruiters in high school in the 1980s, in gay pride parades, and now with forcing gay marriage into law. Sexual abuse of children is a side effect of those three movements (the most direct one being the teenage recruiters who so much want OTHER people to be gay, that they try to force the issue).

        • pagansister

          Interesting observation—-though I disagree that a gay man is any more likely to abuse children than heterosexual males. As for “recruiters”? If a male isn’t interested due to the fact they are heterosexual, then they will tell the guy to buzz off. I don’t think a heterosexual can be “recruited” as homosexuality isn’t a life style, but just who a person is.

  • http://www.thoughtsfromanamericanwoman.wordpress.com Patty

    This was a very good article as well as the comments. But I must disagree with the estrogen article in older women or those that had multiple pregnancies. I am one of those rare women that have more than enough estrogen, thus causing my breast cancer, I have had a complete hysterectomy and am still producing estrogen..so saying that as we age it diminishes is incorrect, at least in my case. And I do not understand why that would “cause” homosexual children. I am not a theologian nor am I an expert in genetics, but I am a Christian who studies the word of God and it is expressly objected to in the bible and as not coming from God. Same sex marriage doesn’t come from God, neither does sexual crimes/abuse, murder, adultery, etc and sadly people do these things – but just because some people do these actions it doesn’t mean they come from God. Do I love homosexuals, yes I know a few and admire them – they are children of God and I pray for their salvation and I value them for what they have to offer.

  • Sus

    Patty, our bodies are all different. Some women don’t produce estrogen at the same levels of other women. I hope and pray you have NED. I’ve been down your road.

    Homosexuals do not commit sexual crimes/abuse, murder, adultery, etc any more than heterosexuals do. You are believing myths about homosexuality that do not exist.

  • http://ashesfromburntroses.blogspot.com/ Manny

    Rebecca, this is the study I mentioned in the other article:

    Obviously it’s a complex phenomena, and whether its completely environmental or purely genetic or a combination, it’s completely outside of a person’s choice. Take me outside this marriage debate i have a lot of compassion for homosexuals. Unfortuantely this marriage debate has really polarized people and if gay marriage wins out, I don’t know how gracious I can be on other gay issues. It’s one of those issues that will polarize for life times and generations.

    • Ted Seeber

      I resemble that remark- which is why I was a liberal young idiot for civil unions before I was an evil Catholic bigot for civil unions.

  • Bill S

    “Those who have attraction to the same sex are called to celibacy as are those not blessed in the sacrament of marriage.”

    I’m trying not to hog the conversation anymore. But I need to answer this. This is not a workable solution. Life will never be like this for everyone. Contraception is the more pragmatic approach.

  • Bill S

    Wait a minute. If this is about homosexuality then forget about what I said about contraception. I was only responding to the part about waiting until getting married to have sex.

    That’s it for my comments for now. I’m trying to cut down.

  • Ted Seeber

    One of the more interesting studies I’ve seen on this subject as of late, suggests that the same gene that produces an inclination towards homosexuality in males, very well might in the same family produce hyper-heterosexuality in women. Apparently, according to this study, the women in families with gay men all had greater than the average number of children for their culture.

    If so, it would indicate both how the gene replicates in society, AND give a potential indication for why promiscuity is so much a part of homosexual culture- I could easily see such a family’s traditions coming to the same conclusion as Bill S., that abstinence is impossible.

    Doesn’t make it true (either way) but it’s a very interesting line of inquiry.

    • Mike

      Darryl Bem’s Exotic Becomes Erotic IMHO holds most explanatory promise. Also IMHO there is no straight gene either. How can there be some gene that controls for what turns you on? There are millions upon millions of different things, situations, foods, etc. etc. that have that effect on people, how could a gene or even a thousand genes control how all those things are interpreted in the brain? I think that’s very unlikely.

      If anything I think we’ll discover that same sex attraction is an unintended consequence of some other gene expression. Because afterall it can’t have any real evolutionary benefit. And come on the gay uncle theory? That is just uber wishful thinking and fantasy. I bet you most scientists are just totally terrified of questioning this emerging consensus for the hate and threats they’d receive from the extremists, but one day, when this all cools off the truth will emerge. Look in Holland where being gay is totally and uterly embraced and celebrated gay people still have way way more health problems and mental health issues. Whether it is in born or chosen or to what degree there’s not doubting one thing: it’s a cross to bear.

  • http://thomascwaters.com Thomas Waters

    Your comments about identified homosexuals who could perform as heterosexuals is problematic. Sexual orientation and behavior are not one in the same, and behavior is not based even partly on the ” same-sex attraction was so profound.” Such an idea is pure garbage.

    Sexual Orientation is understood scientifically to be fluid and exist upon a spectrum running from exclusively heterosexual to exclusively homosexual. In between these two ends of the spectrum are the majortity of people who are some amount of bisexual. Even those whose orientation is exclusively homosexual can perform with a member of the opposite sex. Stimulation is stimulation. I believe the more appropriate idea is that some people are able to compartmentalize their orientation and adhere to social and gender constructions, where as other feel no need to supress their orientation.

    Your argument against same-sex unions- that they are sterile and do not make humans is flawed on several levels. 1) Heterosexual couples may be sterile, and yet we, as a civil government do not refuse to issue them marriage licenses. In other words, access to Civil Marriage is not based on the ability to make babies. 2) Same-sex couples have and raise children all the time and deserve the same legal protections for their families as opposite sex couples. My closest friend was married and had two children before getting a divorce. Then a number of years later, she came to realize that she was a lesbian. She and her partner have been together about 15 years and raised the children. As a couple one partner can not impregnate the other, but that doesn’t make them any less of a family. 3) Same-sex couples use many of the same options that are available to opposite-sex couples such as surrogacy, adoption, fertility medicine, sperm donation, etc. Since opposite sex couples use these techniques to start a family, why are these not equally valid within same-sex couples? 4) But the biggest flaw in your argument is that people are not breeders. Human beings are not like many mammals who go into heat, and by hormones alone find a mater and “breed.” In fact the term “breeder” to describe heterosexuals is pejorative! Yet that is the basis of your argument? Love, intimacy, family, and sex are all complex parts of being human, and it is offensive to think of marriage as being about animal husbandry albiet human.

    There is no such thing as homosexual marriage or heterosexual marriage. But there are same-sex couples and opposite sex couples, and all of them can and do form loving, committed and meaningful relationships and families. ALL of those families deserve the legal protections that Cicvil Marriage affords. For example, my partner and I have been together for over 16 years, and even though both of our names are on our house deed, if one of us would die, the other would be forced to pay taxes on the other’s half of the property which would not be the same if one of us was a different gender. That is unfair! The ability to make a baby has nothing to do with fairness.

    There have been since recorded time, and in all cultures persons who experienced same-sex attraction, and there always will because sexual orientation is a naturally occurring part of the human experience. There will always be heterosexual people and there will always be babies born. Grating same-sex couples the right to receive a civil marriage license will not harm that in any way. In fact, allowing same-sex couples the right to Civil Marriage will only strengthen the institution of marriage and help families.

    PS: to Ted Seeber- there is no greater amount of promiscuity in homosexuals than in heterosexuals! The proof of this is evident in the number of out-of-wedlock births ad the number of births that happen less than nine months following a wedding. Heterosexuals are extremely promiscuous, and always have been! Even in the 1950′s, the so-called “golden era” of perfect families, there were tons and tons of shot gun weddings! Breeders are promiscuous! As I mentioned before my partner and I have been in a loving committed relationship for over 16 years! Because as a society we have had no way to measure or record same-sex commitment, is it easy for people to accuse gays of being promiscuous, ad it is an undeserved accusation!

    There is only one rational argument against same-sex marriage, and that is a theological one. Some people of Faith believe it is a sin. But our Civil Government issues marriage licenses, not the Church, so this alone is no reason to keep same-sex couples from marrying. As for God, I will happily stand before my Maker and proudly own that I have been in a loving committed relationship with my partner for so many years. I think God will approve, even if some human beings think otherwise. If YOU feel it is against YOUR religious beliefs for two same-sex people to marry, then no one will force YOU to marry a person of the same-sex! But don’t force your theology upon my partner and I who are a loving and committed couple. My Civil Marriage won’t strop you getting into heaven!

  • http://thomascwaters.com Thomas Waters

    I would also ask anyone of Faith and especially Catholics to ponder Galileo as they also pass judgement on gays and lesbians. At an earlier time in the Church’s history, Copernicus and Galileo were horribly treated by the Catholic Church because at that time, they believed the Holy Bible proved that the Sun rotated around the Earth. Today, we know that Copernicus ad Galileo were correct, and Astronomy and Faith in God could both exist.

    Today, the Church is at a similar crossroads. Biology, Genetics, and everything that goes into the determination of human behavior is not fully understood. You could say, we know as little about this Science as they knew of Astronomy way back then. So, why have People of Faith learned so little from their history, and feel compelled to again use few lines of text within the Holy Bible as proof that Science is wrong when Science calls the broad spectrum of Sexual Orientation natural and normal? I have no doubt that in another 40o years, people will look back and wonder what was wrong that the people of TODAY were so close-minded? At some point every one will recognize that all persons gay and straight are a part of the complex thing we call being human, and all a product of an Amazing God- a God we can barely even begin to believe we comprehend fully.