Multiple factors involved in sexual orientation, part 2

I posted 2 weeks ago about this twin study but it is now making the media.

Here is the abstract of the article from Archives of Sexual Behavior:

There is still uncertainty about the relative importance of genes and environments on human sexual orientation. One reason is that previous studies employed selfselected, opportunistic, or small population-based samples. We used data from a truly population-based 2005–2006 survey of all adult twins (20–47 years) in Sweden to conduct the largest twin study of same-sex sexual behavior attempted so far. We performed biometric modeling with data on any and total number of lifetime same-sex sexual partners, respectively. The analyses were conducted separately by sex. Twin resemblance was moderate for the 3,826 studied monozygotic and dizygotic same-sex twin pairs. Biometric modeling revealed that, in men, genetic effects explained .34–.39 of the variance, the shared environment .00, and the individual specific environment .61–.66 of the variance. Corresponding estimates among women were .18–.19 for genetic factors, .16–.17 for shared environmental, and 64–.66 for unique environmental factors. Although wide confidence intervals suggest cautious interpretation, the results are consistent with moderate, primarily genetic, familial effects, and moderate to large effects of the nonshared environment (social and biological)
on same-sex sexual behavior.

Reactions are mixed but not really along any ideological grounds that I can see. For instance, from ScienceNOW:

J. Michael Bailey, a psychologist at Northwestern University in Evanston, Illinois, who led earlier twin studies of sexual orientation, calls the new study “good, important, and one unlikely to be bettered in the near future.” But Jonathan Beckwith, a geneticist at Harvard Medical School in Boston, says that the new work fails to overcome a number of problems faced by previous twin studies. He notes that the final sample included only 12% of the males in the Swedish registry, leaving open the possibility of recruitment bias. And Beckwith says that the failure to control for family environment could inflate estimates of genetic influence.

Co-author Qazi Rahman, was quoted by the Washington Post:

“This study puts cold water on any concerns that we are looking for a single ‘gay gene’ or a single environmental variable which could be used to ‘select out’ homosexuality — the factors which influence sexual orientation are complex. And we are not simply talking about homosexuality here — heterosexual behavior is also influenced by a mixture of genetic and environmental factors,” study co-author Dr. Qazi Rahman, a leading scientist on human sexual orientation, said in a prepared statement.

I intend to devote at least one more post to this study as I agree with Michael Bailey that it is an important study. I think along with the other 2 population based studies (Bailey’s in 2000 and Kendler’s also in 2000), it provides a picture of modest genetic effects along with a major role for non-shared enviromental factors. Many roads lead to a similar result. Nothing in this study provides a clear picture of what those environmental factors are but a simple environmental explanation (e.g., poor parenting) or genetic source (single gene, or uniform action of several genes) is not supported here.

Rahman added in the Post article:

“Overall, genetics accounted for around 35 percent of the differences between men in homosexual behavior and other individual-specific environmental factors (that is, not societal attitudes, family or parenting which are shared be twins) accounted for around 64 percent. In other words, men become gay or straight because of different developmental pathways, not just one pathway,” Rahman said.

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Comments

  1. Evan says:

    Drowssap,

    Immune events may become the next candidate for environmental influences. The hormonal hypothesis is not faring well right now.
    Last December a team of Dutch and British researchers failed to find a significant correlation between levels of androgens in the womb and masculine vs feminine toy preference inside the same gender group.

    Cornelieke van de Beek, Stephanie H. M. van Goozen, Jan K. Buitelaar and Peggy T. Cohen-Kettenis, Prenatal Sex Hormones (Maternal and Amniotic Fluid) and Gender-related Play Behavior in 13-month-old Infants,
    DOI 10.1007/s10508-007-9291-z.

    Abstract

    Testosterone, estradiol, and progesterone levels were measured in the second trimester of pregnancy in maternal serum and amniotic fluid, and related to direct observations of gender-related play behavior in 63 male and 63 female offspring at age 13 months. During a structured play session, sex differences in toy preference were found: boys played more with masculine toys than girls (d = .53) and girls played more with feminine toys than boys (d = .35). Normal within-sex variation in prenatal testosterone and estradiol levels was not significantly related to preference for masculine or feminine toys. For progesterone, an unexpected significant positive relationship was found in boys between the level in amniotic fluid and masculine toy preference. The mechanism explaining this relationship is presently not clear, and the finding may be a spurious one. The results of this study may indicate that a hormonal basis for the development of sex-typed toy preferences may manifest itself only after toddlerhood. It may also be that the effect size of this relationship is so small that it should be investigated with more sensitive measures or in larger populations.

  2. Drowssap says:

    Evan

    Interesting results on that study.

    Maybe an early life or in some cases prenatal immune response alters hormone flow in a specific part of the brain. So it’s still hormones, just not the normal range of prenatal hormones.

    It seems to me that if SSA was the result of a high or low level of prenatal hormones

    A) Pregnant women wouldn’t deliver that amount of hormones very often
    B) It would be super easy to test and understand. A significant drop or increase in prenatal hormones would correlate with SSA. We would have probably figured out SSA in the 1950s.

  3. jayhuck says:

    Evan,

    But as I said in a previous message we still don’t know whether something went wrong or not to produce a type of attractions that does not have reproductive potential.

    First you would have to define what “went wrong” means, and that in and of itself will be tricky. If we should discover one day that a type of genius/high IQ developed through means we might consider “wrong” would we work to extinguish it? This is , IMO, what is at the heart of the discussion. I don’t care that scientists are studying sexuality – in terms of knowledge, I think it is a wonderful thing – it is what we DO with that knowledge that counts. Gay people are here to stay, and the more pressing concerns are in how we live with them and how we make sure they and their loved ones and families are treated with love and respect. We also have to make sure that they are treated equally under the law

  4. Evan says:

    Jayhuck,

    I don’t expect, actually, that research will find that something “went wrong” in the case of primarily SSA-ed people. I think it’s equally likely that same-sex attractions be one possibility of the human brain, just like so many others. However, lack of any opposite-sex attractions would be something unusual for a living being that needs this type of attractions to pass life on to new generations.
    I don’t think there is any person or group that can seriously be in the business of extinguishing gayness. Supposing there is, this is out of anyone’s control. Gay people could freely have kids to pass their genes on. I think this is more a question of options than control. If it becomes an option, it becomes less controversial, a low-stake issue. Maybe that’s what gay people need, to lose center stage in order to be left alone.

    If we should discover one day that a type of genius/high IQ developed through means we might consider “wrong” would we work to extinguish it?

    That’s a paradoxical question, which reminds me the kind of dilemmas which Russian novelist Dostoevsky used to pose. He would say something like this: if you were given the choice, would you plunge into suffering head down and heels up and understand life in all its terrible depths (the genius), or would you live a happy and contented life without needing to know more than you need for practical purposes (the ordinary man)?
    Since we live in a society built on the “pursuit of happiness” principle, I think most people would chose contentment over knowledge. But in every given social context you can find dissenters, people who are willing to give up comfort for uncertain benefits, like genius.

    But I’m not sure that genius is the product of accident, otherwise great human achievements would be accidental outcomes of a flawed biology. That would be the real tragedy: to find out that our subjective agitation stems from a biological accident and is not connected to a higher principle. If so, then finding the roots of this accident is tantamount to solving the problem that made humans question it in the first place. Which would then make us wonder why, of all species, only we were able to question and solve the problem, although other species underwent similar biological accidents which never lead them to genius?
    We’d go back to a higher principle…

  5. Evan says:

    Drowssap,

    If you asked scientists about the causes of delinquency, they would say just about the same thing: hormones and genes. This sums up the state of knowledge on the subject of causation of a great deal of psychological outcomes. :|

  6. Michael Bussee says:

    Responding to Eddy:

    “Many felt that he owed an apology to Exodus.” Why to EXODUS specifically? The Apology, if you read whole thing, was directed to anyone I may have hurt: http://www.beyondexgay.com/article/busseeapology My intention in leaving EXODUS was not to hurt EXODUS, but to live honestly.

    “Was he already of a double-mind when I met him and trusted him as a leader?”. No. That came later. In 1974 (through about 1978), I was full of hope and faith — and believed God would change me. Gary had the same hope and faith. I can’t recall exactly when I started having doubts about teaching that people should and could become “ex-gay”, but it wasn’t all about my deepening feelings for Gary. (And by the way, I did not have a child at the time. My child was born in 1978. Only Gary had kids when you first met us.)

    As for when I became “double-minded” — It wasn’t “when Gary showed up” as you suppose. And, I did not become “double minded” . I changed my mind. My faith in the whole message and process began to slip little by little. I began to change my mind when I noticed that no one in our ministry was becoming straight and that many were becoming despondent, depressed and self-destructive, It was a process of disillusionment, not a moment.

    “Did he and Gary carry their big secret throughout that conference?”
    No. There was no “big secret” at the time of the conference!!! I had met Gary in 1975 and although I immediately liked him and was attracted to him, we did not become sexual with each other until 1979 — the same year we left EXODUS. Our divorces were not final until a couple of years later.

    So in a way, yes, you were indeed asking when we first had sex — because you assumed we must have been “carrying some big secret” like an affair — , misleading you and other conference attendees back in September of 1976. We were not.

    “Gary was my ride from my host home to the conference site. The apology isn’t a big deal but the other apology brought it back to the surface.” That car ride from Gary was in 1976, We got sexual and left in 1979, so you can relax. Your chauffeur was sexually pure at the time. You were not being deceived. We were both faithful to our wives when you met us. If you think I owe you some sort of apology for cheating on my wife three years after you first met me, I just don’t get it. I wasn’t married to YOU.

    I have apologized to everyone I might have hurt during my time with EXIT and EXODUS — whether by my misguided teaching (that gays can and should become “ex-gay”) or by my behavior. EXODUS gets no apology for my leaving. It was the honest and right thing to do.

    So all that being said, I agree with Ken when he said: “To me it appeared your persistence in defining the time-line of Michael and Gary’s relationship was to attack and discredit Michael. And that it failed because Michael had already been forgiven, by the short list of people (a list you are not on) he needed to forgive him, for cheating on his wife

    If anything, I think that you, Eddy, owe me an apology for (1) assuming we were already cheating (for implying that we were lying and “carrying a big secret” when you first met us) and for (2) questioning my truthfulness about just who planned and presented the Survivor Conference.

    As I have said, I wish I could take credit for it. Soulforce and Beyond Exgay did it all with no help from me. It simply needed to happen. Those harmed by EXODUS needed and found their “voice” and there was much healing in meeting other Survivors who had some postive, but mostly harmful EXODUS experiences.

  7. Drowssap says:

    Evan

    If you asked scientists about the causes of delinquency, they would say just about the same thing: hormones and genes.

    Yeah, you are right. Everything I see is genes and hormones. I think they look at these two things because they are so obvious and easy to measure.

    It’s kind of like scientists discover the two most obvious factors that impact tree growth, sunlight and water. But they don’t know the 100s of other less obvious, specialized factors that are just as important.

    Eventually a scientist takes this general knowledge about plant growth and tries to turn a tree into a fern by altering sunlight and water levels when it’s in a seed state. 8-)

    I think that’s where we were in SSA until recently. Scientists were trying to figure out how genes and hormones create SSA and they came up blank. Both are probably important but I doubt they are the specialized factor that is creating SSA.

  8. Eddy says:

    We’ve really got to let this serious detour die. I do want to clarify though that you and I (and Gary and I) didn’t meet until 1977. Once before in our very early posts I believe you had confused me with Ron Dennis; Ron did precede me by about a year but we were both short, fiery street evangelists. (Ron was close to the inner circle…you, Jim, Frank, Robbi; I was an unknown until after I joined Outpost in 1978. In total, you and I probably spoke for less than 15 minutes during our entire Exodus overlap. LOL! I probably spoke more with Gary as the chauffeur, now that I think about it.) I’m thinking it’s possible we spoke by phone while I worked at Outpost but, generally speaking, Robbi was the Exodus point of contact.

    I did find the video by the way. I still don’t know how to link with the new laptop…going to hook up old keyboard this weekend. Anyway, go to YouTube and search “Beyond Ex-Gay”. (If you search “Michael Bussee”…about a dozen come up that all look similar.) Within the “Beyond Ex-Gay” search, there are two vids with similar names. “Two of Exodus Founders Come Out As Ex-Ex Gay” is the one with the statement that misled me. (the vid you want is by exgaysurvivordan…5:48 I believe.) And the statement is actually the closing statement of the video.

    I coupled the statement with some conclusions I made from observations. There were really only two video statements from or about the conference. (unless that pack of a dozen with you in the same pose is all different). But, you’re featured in both. In the one, it’s just you. In the other, it’s 3 of you making your statements of apology. You’re the principal in both video offerings and nothing gives any hint of how this conference came to be. So, I took you to be a principal…actually THE principal. And the only statement in either video that gave any clue as to how this historic conference came to pass seemed to come in that closing statement. “I’ve been silent all of these years. But when I heard that Exodus and NARTH had hooked up and were having their thing just up the road…maybe an hour away…in my own backyard.y..I couldn’t stay silent any longer.” (The quote may not be exact but is pretty close.) LOL! I’m thinking of one of the promos for this year’s Twin Cities Pride. Michael, I think in the video there’s a period where there should have been a comma. After the last statement should have been “and that’s when I heard about the Beyond Ex-Gay Conference” or “and then I got this call from Beyond Ex-Gay”. But the way the video ended, it was easy to conclude that you were the inspiration for the conference. Evidently, it was a false conclusion. For that I apologize.

    I won’t answer to the allegations about my motives for wanting to know certain things for two reasons: 1) I’ve already spoken to them all before. You obviously don’t believe me. 2) I believe that any further conversation on this needs to happen on that thread not this one. (I do note the ‘recent comments’ section so I’d likely pick up if conversation resumed there.) But, please, I’ve been the sites biggest nag about detours. I feel so guilty…there’s Evan and Drowssap just communicating away ON THE TOPIC…and I’m answering to questions and charges from a long ago unrelated thread. Not a good example at all.

    So, I’ll give you the last word if you want it. Or meet you on the ‘timeline’ thread. (LOL. I don’t know how to find it. It’s not like “timelines” would have been the actual topic or anything.) :-)

  9. Drowssap says:

    Evan

    Speaking of an immune reponse that causes damage… Cytokine damage keeps popping up in all sorts of physical and mental health research.

    One scientist just announced that he believes that managing the bodies immune response could lead to treatments for a myriad of disorders.
    Could Arthritis Wonder Drugs Provide Clues For Other Diseases?

    “I will also discuss whether it is possible — even likely — that cytokines play a critical role in all diseases involving multiple biological processes, thus providing therapeutic targets for all unmet medical needs.”

  10. Michael Bussee says:

    Eddy” “You’re the principal in both video offerings and nothing gives any hint of how this conference came to be. So, I took you to be a principal…actually THE principal.”

    So, in your haste to discredit me, you jumped to conclusuions TWICE — (1) once about who planned the Survivor’s Conference and (2) again when you assumed that Gary and I were already “hiding a big secret” and cheating on our wives when you first met us — which we were not.

    You really blew it, Eddy Jumped to conclusions. Assumed I wasn’t telling the whole truth — that I must be “spinning” something. You were WRONG! Instead of making assumptions, you could have simply asked.

    The vid you are referring to http://www.main-board.com/yt.php?author=exgaysurvivordan was shot after a rally in Palm Springs in 2006, protesting the Love Won Out conference in nearby Indian Wells, not at the time of the Exgay Survivor Conference which was held in Irivine in 2007.

    You are mixing up two different events. The Love Won Out protest was In September of 2006: http://findarticles.com/p/articles/mi_hb5554/is_200608/ai_n21880102. I found out that EXODUS and NARTH had “teamed up” for that one, and were indeed holding the LWO conference “practically in my back yard” — I live about 45 minutes from Palm Springs. I went on my own and spoke as an individual.

    You wrongly assumed that that Palm Springs protest vid (2006) was about the Irvine Survivor’s Conference (2007) http://www.beyondexgay.com/conference — and that was almost a year away. You messed up. You jumped to conclusions and assumed I must be lying about (or “spinning”) something. At least you apologized for that erroenous accusation

    About the “time line” thing. Again, you jumped to conclusions and assumed Gary and I were messing around (“hiding a big secret”) and lying to everyone even as EXODUS was being formed. We were not. How about an apology for that, sport?

  11. Evan says:

    Drowssap,

    Yeah, evidence is growing for some immune contribution to brain disorders. Just today another piece of research made the news. I’m not usually interested in psychiatric stuff, but one thing caught my eye: scientists narrowed the search for bipolars and schizophrenia susceptiblity genes to a set of genes which are involved in “nervous system development, immune system development and response, and cell death.” I have heard this argument before about the role of cell death (apoptosis) in the development of various disorders, but the immune genetic contribution is something new.

    Genes have complicated ways of working together in many parts of the body. For instance one of those susceptibility genes is expressed in the amygdala, the hippocampus, corpus callosum and other parts of the brain, plus the eye retina and kidneys. Could someone make an evolutionary argument for why 1-2% of a population are hit by these disorders? What purpose would having these serious disorders serve such a sizeable portion of the population or the entire population itself? This is not a rare disorder, so it doesn’t look like a genetic accident, because the number of genes involved is big. Maybe it’s the environment that is changing and susceptibilities are differently put to strain by modern stressors.

    On the other hand, SSAs are probably not the product of a disorder in most cases, although there might be some cases in which this type of attractions could be created by some dysregulations. SSAs are one possibility of the brain to perceive conspecifics, but under some conditions specific to individuals, like greater vulnerability to anxiety, their effect might be amplified and might stifle whatever degree of OSAs is present in one individual. Lack of any degree of opposite-sex attractions – that is probably a sign of a dysregulation of some sort. But attractions probably don’t work that way: it’s more of a question of relative thresholds, and less of degrees. One needs a critical level of gender ‘otherness’ perception in order for attractions to kick in.

  12. Drowssap says:

    Evan

    Could someone make an evolutionary argument for why 1-2% of a population are hit by these disorders?

    You can bet that any gene implicated in trouble for 1% to 2% of the population is a susceptability gene, not a disease gene. Disease genes are always rare (roughly 1 in 10,000 people) or group specific. Susceptability genes exist for a lot of reasons. One of the main reasons for these genes is immune function. A gene might offer protection from one thing but this protection makes us vulnerable to another.

    Example:
    Blood type is part of the human immune system. Each blood type is good at protecting us from certain pathogens while not so good at protecting us from others. It’s a trade off.

    Example 2:
    Hemochromatosis is a genetic “disorder” that’s not really a disorder at all. People with Hemochromatosis genes store extra iron for use during long winters or in places where Vitamin C is scarce. This is a huge advantage in cold climate, hunter gatherer societies. The problem is that in the modern environment neither iron nor Vitamin C are scarce. These people often store too much iron which can lead to increased health problems as they age. Fortunately the cure is simple. All these people have to do is donate blood and they’ll never have a problem.

  13. Michael Bussee says:

    Evan, you said: “One needs a critical level of gender ‘otherness’ perception in order for attractions to kick in.”

    Not if you’re gay, you don’t. A perception of “gender otherness” has the opposite effect on me.

  14. Michael Bussee says:

    I am still waiting for some sort of apology from Eddy for his presumptions that (1) Gary and I had “a big secret” when he first met us, (2) that we were lying the entire time we were with EXODUS and (3) that I left EXODUS when “Gary came along” — as though Gary was the only or main reason I left. He was not. I left because I was still gay.

    None of Eddy’s “jumps to conclusions” was correct. We had already known each other about four years before that happenened. During the previous four years, we got EXIT off the ground, hosted the first EXODUS conference and lived “ex-gay” lives, faithful to our wives and kids. Our daughters were born during this time, one week apart.

    We quit EXODUS the same year we began our affair. I remember it well because it was the same night that “Alient” came out at the cinema near where we were giving our “ex-gay” testimony at a church conference in Indianapolis..: http://www.imdb.com/title/tt0078748/releaseinfo.

    This was the same conference where we announced that we would no longer be giving “ex-gay” speeches — to the shock of those who had asked us to talk about how we had “changed”. The conference organizers had accidentally put us up in a room with one bed. We went to the movies that night. We told our wives soon after, but our divorces were not final until 1981.

  15. Eddy says:

    Michael,
    In my earlier post, I said I was giving you the last word. I’m not sure why it is that you’re waiting for me to re-engage in that conversation. Does ‘last word’ mean something different to you?

    I’ve apologized on this site before; I’ve apologized to you before. If I felt I owed you an apology now, I would. Wondering and considering the possibility are NOT the same thing as presumptions. (LOL! If I presumed those answers, why would I need to ask any questions?) For the false conclusion that I did come to (re your role in the BXG conference), I did apologize.

    Ann, Michael

    This discussion has made me realize that the ‘in person California vacation rendezvous’ is an offer I must withdraw..

    …and once again I’ll try to abandon this detour…

  16. Michael Bussee says:

    Eddy: OK. That will have to do I guess. At least I am on record that Gary and I were not messing around before, during or after the EXODUS conference and that we left EXODUS and came out to our wives the same year we did — 1979.

    We could have saved all this time and aggravation by talking or writing to each other when you first started implying that we were lying (over a year ago I think) but I know that for some reason, you preferred to hash out the personal details on the blog. Oh well.

  17. Michael Bussee says:

    Eddy, in all fairness, you went beyond just “wondering and considering”. You referred to it as the “big lie”. If you had just been wondering, why not just ask, “When was that?” I would have answered you honestly and openly

    Your tone and wording strongly suggested that you believed I was trying to pull a fast one on you, EXODUS and the general public. I was not .You assumed that I was lying to you and to EXODUS about the “time line”, but I was not lying about any of that.

    You jumped to the same sort of conclusion about who spearheaded the Survivor conference, suggesting that I was “spinning” the truth about that. I would have apologized to you for such an assumption, but if you don’t feel the need to, so be it.

  18. Ann says:

    This discussion has made me realize that the ‘in person California vacation rendezvous’ is an offer I must withdraw..

    Eddy,

    I’m not sure if I understand – have I done or said something that was inappropriate? Please let me know as I don’t want anything the matter between us. I would love to meet you. You and Michael can come over and I will make lunch or dinner if you want. If you just want to come, that is ok too.

  19. Michael Bussee says:

    I would love to see a summit sometime of those on the ex-gay side of things and those of us who are critical — to see if we could find some common ground. It would be a great conference, wouldn’t it?

  20. Nance says:

    This is my question to the study and those that say “nurture” plays a role in sexual orientation.I’m gay and have blue eyes. Did nurture dictate my eye color?
    I know without a doubt that no part of my nurture promoted my attraction to men.

    By no means do I suggest that I am better qualified according to my education, only by being myself . Thanks

  21. carole says:

    The July 1, 2008 thread entitled “Multiple Factors involved in Sexual Orientation, Pt. 2 had lots of interesting, thought-provoking observations from many of you.

    I wonder if there will ever be a way to know what a toddler or a baby is thinking, what they are taking in? (Just read an article or two about that). People can talk about their earliest memories, but none can really remember being one or two, what they saw at that age, how they processed what they saw).

    I understand that now may not be the time to discuss this, but maybe on another thread we can.

    I have to admit, Michael, that your comment that at a very early age (I forget how young, but it WAS young) you put another boy’s penis in your mouth was on my mind as I thought about this. That still astounds me. You didn’t go for his big or little toe (or maybe you did, LOL) but his penis. I was left wondering what gave you , so young at that time, the interest, the urge to do that. (This is not at all a request for you to attempt to explain it since you already said you don’t know why you did it other than you put all kinds of things in your mouth and other than your earliest memories are those of loving the male body. For that matter, I recall eating mud!)

    My mention of your comment is only by way of illustrating that the exploration of attraction and our childhood is something worth discussing. Seems that whenever people like the NARTHIANS try to link childhood and sexuality, they try to link it to something bad, something traumatic.

    If there is a link (and I am not saying there is but it’s worth discussing) maybe the discussion should center on links to something perceived by the very young child as very attractive and pleasing.

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