Study indicates sexual orientation determined before birth

[Bikewer]

A Canadian study:
http://news.yahoo.com/s/nm/20060627/sc_nm/sexual_orientation_men_determined_before_dc_2

claims to show a relationship between older male siblings and sexuality. The notion, (from the article) is that in cases where there have been several previous male children, there may be an antibody response from the mother.

All very preliminary, with only 844 (including heterosexual controls) subjects in the test.

I know from my previous readings, there has been a thought for years that part of the determining factor might be hormone levels in the mother's bloodstream at various critical phases in the fetus' development.

[andyandy]

I'm sure I've heard this theory before....hasn't there already been studies on this?

[Serenity]

I read “The Agile Gene” by Matt Ridley not too long ago and he makes mention of Ray Blanchard’s theory of fraternal birth order being a factor in homosexuality. He says, for each older brother, a man’s likelihood of being gay increases by 1/3rd. This also has an affect on the weight of each consecutive male child born—each weighing less than the previous. I’ll try and dig up the book for more info later today.

[Mercutio]

Heh...I had always heard it was a result of maternal stress during pregnancy--of course, the more boys one has, the more stress will be present...

[HeyLeroy]

My local birdcage liner had a bit longer report on the study. I'll quote:

A woman's first son has a 2% chance of being homosexual. Her fifth son has a 6% chance. So while that is triple the chance for the fifth son as the first son, there is still a 94% chance she will have a heterosexual fetus.

(it is currently believed that the prevalence of homosexuality in the population is 2% to 4% for males.)

http://www.cbsnews.com/stories/2006/06/26/health/main1753553.shtml

The effect of birth order on male homosexuality has been reported previously, but Bogaert's work is the first designed to rule out social or environmental effects.

also:

This refers to lesbianism, and it's from 1998, but:

http://www.sciencedaily.com/releases/1998/03/980303064433.htm

[CaveDave]

I read “The Agile Gene” by Matt Ridley not too long ago and he makes mention of Ray Blanchard’s theory of fraternal birth order being a factor in homosexuality. He says, for each older brother, a man’s likelihood of being gay increases by 1/3rd. This also has an affect on the weight of each consecutive male child born—each weighing less than the previous. I’ll try and dig up the book for more info later today.
Anecdotal evidence only:

My father was the youngest of four, an eldest sister and two elder brothers. -- He turned out (closet) gay. (Imagine our surprise)

My cousin was the fourth of four boys. -- He is gay.

A friend of mine was third of three boys. -- he was gay and died of AIDS.

A family friend had only two children, sons. -- The youngest is gay.

A family my parents were friends with had three sons after one daughter. -- The youngest is gay.

I have known almost no-one else from a family of more than two boys.

Looks like a trend to me.

Cheers,
Dave

[empeake]

Anecdotal evidence only:

Opposite anecdotal evidence:

The only gay person in my family is an only child.

The gay friends I've had have all been the eldest son.

My wife has 44 first cousins on her mother's side (yes, I live in a Catholic country), divided into 8 families, of which one consists of an only child. That represents an average of ~6.2 children for the other families. Not a single gay among them.

[CaveDave]

My wife has 44 first cousins on her mother's side (yes, I live in a Catholic country), divided into 8 families, of which one consists of an only child. That represents an average of ~6.2 children for the other families. Not a single gay among them.

You're sure about that?

How many were second/third/fourth/fifth/sixth MALE children?

Ever try the paper ring* test on those 44 (or the males among them) yourself?

Do you not admit that there is a strongly entrenched anti-homosexual culture in Mexico and the hispanic community in the US?

Just as my father could not admit that he was gay (after four kids had been raised and left to live their own lives, even though he had frequented bus stations for sex all that time, secretly) until he was too OLD to have a chance with the young dudes.

Many cultures force otherwise gay folks to hide and blend in and "pass" for straight because of the perceived shame of coming out. Denial (De Nile) is not just a river in northern Africa.

*The paper ring test involves placing a snug band of thin paper (postage stamps are commonly used) around the shaft of the subject's penis, such that any arousal will tear the ring, and showing various homo-erotic images to them.

Cheers,
Dave

[empeake]

You're sure about that?
Let me put it this way: in that family, NO secret would be unknown for long.

Ever try the paper ring* test on those 44 (or the males among them) yourself?
A test? :eek: Then it wouldn't be anectodal evidence, would it?

As for myself, just let's say that I'm a quite conventional heterosexual male, with getting into specifics.

[CaveDave]

Let me put it this way: in that family, NO secret would be unknown for long.
If you say so, But ask me or my mother or my siblings about how thoroughly decieved the relatives can be when dealing with a cultural taboo. Don't be so sure that secrets don't exist. Do they know everything about you? :)

A test? :eek: Then it wouldn't be anectodal evidence, would it?
My mistake. Sorry.:o

As for myself, just let's say that I'm a quite conventional heterosexual male, with getting into specifics.
I must take your word for that. No offense, but that was what my father said, before he admitted to years of deception.

[articulett]

Why do they spank babies at birth?
To smack the penises off the smart ones.

(or so I've been told)

CaveDave, your sig ends prematurely...or is that the way it's meant to be--yet another conundrum.

[andyandy]

why journalists shouldn't try to write about science.....

http://commentisfree.guardian.co.uk/peter_tatchell/2006/06/born_gay_or_made_gay.html

This leads Bogaert to conclude that a man's sexual orientation is influenced by the conditions in his mother's womb when he was a foetus; with successive male children triggering changes in the mother's body that increase the chances that subsequent male children will be gay. This so-called fraternal gay birth effect creates a prenatal environment that fosters homosexuality in younger sons.

Nice theory, shame about the exceptions. I hate to rain on Bogaert's research, but I am a first-born son and definitely capital GAY. Oh well, never mind. There are bound to be exceptions. Just because I don't personally fit his theory doesn't automatically invalidate it.


why is him being gay an exception to Bogaert's theory??? :confused:

Stupid frickin journo......:)

[empeake]

Do they know everything about you? :)
I sure hope not, as I would have to kill them. ;)

I must take your word for that. No offense, but that was what my father said, before he admitted to years of deception.
None taken. Actually, I'm the one that should apologize in case any of my comments way have come across as insensitive. I'm aware that the situation you went through must have been very difficult, and by sharing it with us you deserve my full respect and support.

[CaveDave]

Why do they spank babies at birth?
To smack the penises off the smart ones.

(or so I've been told)
:D

CaveDave, your sig ends prematurely...or is that the way it's meant to be--yet another conundrum.
Yeah, when I got my custom title the last part vanished. I haven't fixed it yet.

Dave

[CaveDave]

I sure hope not, as I would have to kill them. ;)
:D

None taken. Actually, I'm the one that should apologize in case any of my comments way have come across as insensitive. I'm aware that the situation you went through must have been very difficult, and by sharing it with us you deserve my full respect and support.
I did not take your remarks as insensitive at all, I was just debating the points you made, hopefully in the spirit of good skepticism and good cheer.:)

The pain is mostly in the past, now. (The worst part was growing up in a town where everyone else seemed to know but us, and not understanding why we were reviled and mistreated at school and such.) At least I have gotten over the shame and come to accept the truth.:)

Cheers,
Dave

[Serenity]

Anecdotal evidence only:

My father was the youngest of four, an eldest sister and two elder brothers. -- He turned out (closet) gay. (Imagine our surprise)

My cousin was the fourth of four boys. -- He is gay.

A friend of mine was third of three boys. -- he was gay and died of AIDS.

A family friend had only two children, sons. -- The youngest is gay.

A family my parents were friends with had three sons after one daughter. -- The youngest is gay.

I have known almost no-one else from a family of more than two boys.

Looks like a trend to me.

Cheers,
Dave
CaveDave – Sounds like you’ve healed well from the ordeal. The fact that you can openly discuss it here means you’ve successfully escaped the brunt of the shame that normally gets passed along from this. I blame the society of the times that condoned the violence and harassment of homosexuals forcing them underground. It saddens me to think of all the broken lives trying to fit into some rigid cultural standard. People were cruel then and they can be as cruel today. It takes constant vigilance against this sort of thing.

I looked up the relevant chapter in the book, Agile Gene regarding fraternal order. It’s preceded by the study on index and ring finger lengths as an indicator of testosterone exposure prenatally—long ring finger suggesting greater testosterone exposure. Something to do with the hox genes that control both genitalia and digit growth and the timing of events. A visual might serve well here: http://www.unl.edu/rhames/courses/readings/homofinger/homo_finger.html (http://www.unl.edu/rhames/courses/readings/homofinger/homo_finger.html)

Now back to the fraternal order study. Blanchard says one and seven gay men had their homosexuality imprinted by fraternal order. He mentions weight as an indicator also. Normally a baby born after another is born heavier, especially a boy born after a girl. A boy born after another boy is typically slightly heavier until you get to the third or more successive boys, tending to be smaller and lighter than the previous. Reference--Journal of Biosocial Science 33:451-67

He goes on to discuss the womb having been occupied by boy’s occasionally results in a larger placenta, lower birth weight, and homosexual tendencies, marking the fetus for life resulting in a maternal immune reaction as mentioned by Mercutio earlier in the thread. New information suggests something related to the gene PCDH22 on the Y chromosome. I’ll stop there; you can find it all in Chapter Six of Ridley’s book.

Speaking of family secrets, I watched a foreign film yesterday – The Sea (http://www.blockbuster.com/catalog/DisplayMoreMovieProductDetails.action?movieID=1203 49&channel=Movies&subChannel=sub#Cast), about a dysfunctional and corrupt Icelandic town coping poorly to the changing times. The family dynamics and dinner discussions were cringe-worthy to say the least. Incest and rape abound, and shockingly expected. All incest and rape aside; worth watching for anyone involved in a sour family business environment.

[GregC]

Exception to the theory:

My only son. Eldest child. Gay.

[empeake]

In the past decades, the average number of children has been on the decline in most industrialized nations. Based on this theory, the percentage of homosexuals would also be lower, since most chlidren would have one or less older siblings. Likewise, the greater average number of children in certain countries would lead to a higher prevalence of homosexuality.

I recall once having heard that the percentage of homosexuals is esssentially the same in all countries (can't remeber the source, sorry). Does anyone have more information about this subject, if the percentage of homosexuals varies from country to country, or if the percentage of homosexuals has risen or declined in the past decades in a specific country?

[casebro]

What about lesbianism? Totally different cause?