(If you came searching for ALO's Barbeque, click the word. It's a good song, that's why I borrowed it's lyrics.)

Monday, December 28, 2009

Hormone Wash in the Brain

I have been asked about the science of a hormone wash in the brain. There is no proven link, but there have been some studies. I'm not a science writer, that's more my husband's field. While I have done a lot of reading on gender identity, I tend to remember things without recalling the actual sources. So, there might be better links, but here's what I found in a quick search. In Foetal testosterone and the child systemizing quotient they discuss animal models:
"In animal models, the critical period for sexual differentiation of the brain occurs when the differences in serum testosterone between sexes are highest (4). Studies reveal that the greatest sex differences in foetal testosterone (fT) levels are detectable between weeks 14 and 16 of gestation (5)....Finegan, Bartleman and Wong (6) proposed that the amniotic fluid, obtained from routine amniocentesis, could be used to measure prenatal hormone levels during the critical period for sexual differentiation of the brain; the variation in prenatal hormone levels could then be linked to later development of cognition and behaviour."
Studies of male fetus: a hormonal wash physically alters the male fetus’s brain and masculinizes it to produce male sexual behavior. It also creates many of the typical differences seen between the sexes, like girls’ superiority at speech and boys’ at spatial tasks. (Carter, Rita, Ed. Mapping the Mind. CA: University of California Press, 1998.
I do know that while some transgender children become disturbed by their changing bodies at onset of puberty, many children insist on a different gender identity than their biological gender assigned at birth as soon as they can speak.

No studies show that some sort of predetermined set of environmental parameters influence gender identity. This, of course, is what everyone presumes. "Oh, your child was surrounded by girls in the orphanage, no wonder 'he' likes girl things." or "Your child was probably sexually abused, that's why 'he' is transgender." Neither of these situations have been shown to determine gender identity. Actually my child was surrounded by girls and boys at the orphanage, and at the public school she attended. Contrary to popular assumption, the Chinese orphanages are full of boys, some healthy or just "too old" and others born with special needs. Often this means cleft palate or club feet. And sometimes the child is transgender. Which family this child enters will determine their future. We had three boys. Maybe somebody was giving us a sign, "Hey dummy, you were supposed to adopt a girl!"

Also see In Womb Development of the Transexual Brain written by Tamara Sheehan
Also see Transsexual differences caught on brain scan 12:16 26 January 2011 by Jessica Hamzelou


  1. Life makes coincidences and we interpret them. So I learned at Landmark Education that if you are going to assign a meaning, make it one that works for you. Out of that, I suggest that the sign is only "you can be the best possible parents for this child." And, you are proving that you are up to helping your adopted child find their own identity and express their own sexuality. I can only hope that I would be so giving a parent. Either way, I'm very glad for all your children that you listen to who they are not just who you expected that they might be.

  2. We have all seen the Nat Geo and Nova specials on "birth of a baby" from conception to delivery. They make reference to the "testosterone wash" of the brain that gives the male fetus a masculine perspective (which usually manifests itself at puberty). Occasionally, and inexplicably, that wash does not occur, leaving the fetus with the default estrogen influence and feminine perspective. When homosexuals say they were born that way... they were. It is a biological fact. Political correctness, however, forbids our referring to it as a birth defect, which, of course, it is.

  3. My baby was conceived with a fertility drug Clomed. Do you see any link to fertility drugs and sexual identity issues? I has an intuition that makes me feel there could be a reason people are conceived with hormones are not born by the sex they are. If this makes any sense? Please let me know what you think.

    1. I can see why you wonder this, and some association may be discovered in the future. I have not seen studies, so far, linked to fertility drugs. Sometimes conditions can be concurrent but not linked. For instance, parents in transgender support groups have wondered whether there is a link with the autism spectrum because they know children with both. No study has linked these conditions which are, so far, considered concurrent but not linked.

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  5. Food for thought: Recently a book was written about the Maines identical twins, one turned out to be transgender. How does this relate to the hormone wash? Who knows. Fetuses mature within two sacs...chorionic and amniotic. A singleton is within both. Twins can each be within their own chorionic and amniotic sac (usually fraternal twins, but possible to be identical), or there can be one chorionic sac surrounding a twin each within their own amniotic sacs (definitely identical [as far as I know]), or both within one amniotic sacs (identical and dangerous...can result in conjoined twins.) Can this information relate to the Maines' story? They were adopted, so we don't know this kind of medical information. (My identical twins [both cis] shared a chorion, but not an amnion.) Either way, science is complex.