On the Science of Changing Sex

Shades of Grey…

Posted in Brain Sex, Confirming Two Type Taxonomy, Female-to-Male by Kay Brown on February 23, 2015

shrinking brainShades of Grey… Matter

We live in exciting times – At least scientifically.  We can now peer into the heads of transsexuals to see if their brains exhibit sexually dimorphic features that match their natal sex or their preferred gender.  Years ago, Ray Blanchard made a prediction, based on early evidence that there was a taxonic difference between “homosexual” and “non-homosexual” transwomen in sexuality, natural gendered mannerisms, age of transition, etc, that the former would show sexually dimorphic features in the brain that were shifted in the female direction while the latter would not, but would show features that were different than controls, but that they would not be sexually dimorphic features, and definitely not shifted in the female direction.  We now have yet more evidence that that prediction is correct, giving more weight to the two type taxonomy of MTF transsexuality, namely exclusively androphilic vs. autogynephilic.

The best evidence would be to use two populations of transwomen, one known to be exclusively androphilic and the other not, and test them for the same features, using the same type of measurement.  We now have that data for grey matter distribution in the brains of both types of transsexual.

In the earlier Savic and Arver paper, they compared grey matter distribution of 24 gynephilic transwomen, before HRT to that of heterosexual men and women.  (Remember, HRT itself causes a shift in sexually dimorphic features due to activational effects of sex hormones, and the lack of such hormones.)  The conclusion?

“The present data do not support the notion that brains of (gynephilic) MtF-TR are feminized.”

In the later Simon paper, they compared grey matter distribution of 10 exclusively androphilic transwomen, and 7 exclusively gynephilic FtM transmen, before HRT to that of heterosexual men and women.  The conclusion?

“Our findings support the notion that structural differences exist between subjects with GID and controls from the same biological gender. We found that transsexual subjects did not differ significantly from controls sharing their gender identity but were different from those sharing their biological gender in their regional GM volume of several brain areas, including the left and right precentral gyri, the left postcentral gyrus (including the somatosensory cortex and the primary motor cortex), the left posterior cingulate, precueneus and calcarinus, the right cuneus, the right fusiform, lingual, middle and inferior occipital, and inferior temporal gyri. Additionaly, we also found areas in the cerebellum and in the left angular gyrus and left inferior parietal lobule that showed significant structural difference between transgender subjects and controls, independent from their biological gender.”

The choice to explore only “homosexual” transsexuals in this study was informed by the researchers’ knowledge of the Freund/Blanchard taxonomy and of Blanchard’s prediction, as they explained,

“Both MTF and FTM patients were eligible for the study, but only those with homosexual orientation. The rationale for this choice was based on the Blanchard typology which considers two fundamentally different types of transsexualism: homosexual and nonhomosexual. Homosexual transsexual individuals are sexually attracted to the same biological gender, while nonhomosexual transsexual individuals are attracted to either the opposite gender or show no sexual orientation/attraction at all. According to Blanchard, homosexual transsexuals are usually younger at initial presentation of gender identity disorder and show more pronounced and frequent childhood femininity, as well as different anthropometric data. One might argue that mixing individuals from both transsexual groups in one study targeting the neurobiological background of transsexualism might bias the results by introducing heterogeneity in the sample. Thus, in our study, only homosexual transsexual individuals were included preventing our findings from the aforementioned bias.”

This points to growing recognition within the scientific community that the two type taxonomy is correct.  They went further, indirectly referring to the taxonomy and Blanchard’s prediction,

“In another study also limited to MTF transsexuals Savic and Arver, reported no “feminization” of any brain region with regard to structure. Nonetheless, certain brain areas (clusters ≥100 voxels) showed characteristic structural features in the transsexual group compared with both male and female control groups. Specifically, they found reduced thalamus and putamen volumes and increased GM volumes in the insular and inferior frontal cortex and in the right temporo-parietal junction (angular gyrus and superior temporal gyrus) in the transsexual group compared with both control groups. In our study, however only the angular gyrus (but in the left hemisphere) was affected among these areas, showing lower regional GM concentration in both FTM and MTF transgender subjects compared to controls, independent of their biological gender. When comparing the results reported by Savic and Arver to either our study or to other imaging studies in the literature of transsexualism, it has to be taken into consideration that their reported results were obtained from a solely nonhomosexual transsexual group of patients. The lack of real overlap between our and Savic and Arvers’ findings, despite the very similar methodology used, might at least in part be explained by the difference of the sexual orientation of the two samples.”

Truly, exiting times.


Ivanka Savic, Stefan Arver, “Sex Dimorphism of the Brain in Male-to-Female Transsexuals”

Lajos Simon, Lajos R. Kozák, Viktória Simon, Pál Czobor, Zsolt Unoka, Ádám Szabó, Gábor Csukly, “Regional Grey Matter Structure Differences between Transsexuals and Healthy Controls—A Voxel Based Morphometry Study”


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Child’s Play

Posted in Female-to-Male, Science Criticism, Transgender Youth by Kay Brown on February 9, 2015

critical-thinkingFor years, critics of transkids’ identities have made claims that transkids are either “confused”, “delayed”, or “pretending”.  Many papers describing feminine boys from the 1960’s would describe them as being “talented mimics”, explicitly taking the position that men and women, boys and girls, do in fact have in-born differences in behavior, mannerisms, and motor-movements, but that these feminine boys were NOT exhibiting natural behavior, but were consciously, or “subconsciously”, observing girls and women, and learning to “mimic” these behaviors.  Of course, those of us who were such and grew up to transition, have long begged to differ!

Today, we have a published paper that demolishes these notions.  At the core of the paper is the ability to determine implicit associations between concepts.  If you are not familiar with this tool, it may be useful to review the Wiki page on Implicit Association Testing .  One of it strengths is that it cannot be “faked”.  It is impervious to Social Desirability Bias or other impression management distortions.  It is also impossible for someone to be “pretending”, as the cognitive load to evaluate the test set-up, determine the “right” answer, etc. would create an obvious delay in the test.  Further, if a child were “confused” as to the meaning of sex and gender, there would be an obvious anomalous signature in the test results.

ImplicitThe study involved 32 transkids, ages 5-12, 12 FtM, 20 MTF, who have already transitioned full time, with the full support of their families.  This would obviously include “early onset” transkids.  However, and this is critical, we know, or at least suspect, that some of these kids will “desist” being gender dysphoric before puberty, if they follow the trend already seen in other studies, most especially the Steensma study from the Netherlands.  Yet, for all of that, the results of the study show that these kids are completely consistent in their implicit gender identity and preferences as their opposite sex, non-trans, controls and siblings.  They are NOT pretending, nor confused.

The folks who conducted this recent study are continuing their work, looking at these kids as they grow up.  They are looking for additional transkids to join the study.

Study on Gender Nonconformity in Children

Hi from the TransYouth Project at the University of Washington! We are researchers interested in gender development in children and have a new research project we are currently recruiting families for. The project aims to better understand gender development in gender nonconforming and transgender children.  Our new study takes 30-60 minutes and includes children ages 3-12. We are running the study all over the U.S. and Canada so please let us know if you are interested and we can let you know when we’ll be in your area. We are hoping to recruit gender nonconforming children as well as their siblings (where applicable). All data collected as part of this study are confidential. Payment is $10 per parent and $10 plus a small toy per child. There is an optional longitudinal component that we can tell you more about as well if you are interested. To sign up for the study, please visit: http://www.transyouthproject.org. If you have any questions, feel free to contact me, Dr. Kristina Olson, via email (krolson@uw.edu) or phone (206-616-1371). Thanks for considering being a part of this research or telling someone who might be!


Kristina R. Olson, Aidan C. Key, Nicholas R. Eaton, “Gender Cognition in Transgender Children“, Psychological Science

Thomas D. Steensma, Roeline Biemond, Fijgie de Boer and Peggy T. Cohen-Kettenis, “Desisting and persisting gender dysphoria after childhood: A qualitative follow-up study”


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Are Your Ears Burning?

Posted in Female-to-Male, Science Criticism by Kay Brown on January 19, 2015

critical-thinkingIt has long been hypothesized that prenatal or perinatal hormone levels influence sexually dimorphic behavior in humans.  The evidence from studies of people with Disorders of Sexual Development and in numerous animals studies lends strong evidence that this is true.  So it would seem natural that we should ask if sexual orientation and gendered behavior in otherwise phenotypically normal individuals could also have been affected by hormones.  The ultimate study would be one that longitudinally follows a large cohort of individuals from conception to adulthood, taking extensive hormonal assays while evaluating gendered behavior and sexual orientation.  The problems of doing such a study for transsexuality is obvious… the cohort would have to be in the hundreds of thousands to ensure statistically significant numbers of transsexual individuals were included.

Thus, researchers are interested in finding sexually dimorphic markers that record historical hormone environments.  That is to say, something that is an organizational and not an activational effect, preferably one that becomes fixed at the same period in prenatal development as organizational effects in the brain.  It must be something that is observable at birth and remains stable long enough to allow us to use it to retrospectively determine ones hormonal environment after we have found our gender atypical population of interest.

I’ve already blogged about one such putative measure, the 2D:4D ratio, which is mildly sexually dimorphic, and in at least some population has a recognizably large enough effect size that we can hope that we can use it.  Sadly, the results have been contradictory so far.  But despair not, another such sexually dimorphic marker is available, though it requires specialized equipment to measure.

In individuals with normal, unimpaired hearing, a curious effect is found in which our inner ears respond to external sounds with sounds of their own, which is known to be mildly sexually dimorphic, as described in the abstract from a recent paper out of Europe, the first known to explore this effect as a potential probe of the role of androgens in gender dysphoria,

“Click-evoked otoacoustic emissions (CEOAEs) are echo-like sounds that are produced by the inner ear in response to click-stimuli. CEOAEs generally have a higher amplitude in women compared to men and neonates already show a similar sex difference in CEOAEs. Weaker responses in males are proposed to originate from elevated levels of testosterone during perinatal sexual differentiation.  Therefore, CEOAEs may be used as a retrospective indicator of someone’s perinatal androgen environment.”

coeaeBefore we get too excited about this marker, we need to look at the effect size, with is quite small at only d=0.30 in the left ear and was better in the right ear at d=0.60.  You may recall that this is of the same order as the 2D:4D finger length ratios at d=0.63.  This is large enough to be useful, but only if enough subjects are available to achieve significant statistical power.  Sadly, this lack of enough subjects seems to be the case in this study.  Too bad, because there is a hint at some exciting results in that looking at a group of gender atypical and gender dysphoric children and teens, the natal males seem to show a shift in the female-like direction, but oddly, the natal females do NOT,

“In the present study, we retrospectively investigated possible organizational effects of prenatal androgens on CEOAEs in relation to gender identity. We found that boyswith GID had sex-atypical (hypomasculinized) emissions. Their mean response amplitudes, though, were not significantly different from either the male or female controls. Thus, boys with GID had an intermediate position between the sexes in terms of CEOAE response amplitudes. By contrast, girls with GID showed emissions in the same range as female controls.  Consistent with several earlier studies, sex differences in emission strengths were observed in the control group, with girls having significantly stronger emission amplitudes than boys. Our finding that boys with GID showed stronger, more female-typical emissions compared to control boys suggests that boys with GID might have been exposed to relatively lower amounts of androgens during early development. The effect sizes for the comparison boys with GID versus control boys were similar to those for control girls versus control boys, supporting the notion of a hypomasculinized early sexual differentiation in boys with GID.  However, considering the lack of statistically significant differences between the control boys and the boys with GID and the relatively small sample size of subjects with GID, this conclusion may still be premature and our results therefore need to be interpreted with caution. Furthermore, our findings did not support the hypothesis of an increased exposure to androgens in girls with GID during prenatal development. Though speculative, this might reflect that GID in girls does not develop under the influence of prenatal androgens or at least not during the same critical time window as when androgens exert influences over OAEs.”

This result is surprising, in that previous studies involving gay men and women, researchers saw the opposite pattern, in that gay men showed no shift from control men, but lesbians showed a shift from the female to the male response.  The most exciting times in science are when you hear, “That’s strange!”  This is one of those times.  Several possibilities exist.  This result could just be spurious, with not enough subjects to have seen the real signal.  It could be that there is an additional activational effect that occurs as children mature, that causes a shift for both gay men and gay women toward the masculine response.  We may be seeing the effect of heterosexual “tomboys” swamping out the FtM signal.  Or, we could be witnessing the first hint that there is a difference between transkids, both MTF and FtM, and conventionally gay men and lesbian women.  Time and additional studies will tell.


Sarah M. Burke, Willeke M. Menks, Peggy T. Cohen-Kettenis, Daniel T. Klink, Julie Bakker, “Click-Evoked Otoacoustic Emissions in Children and Adolescents with Gender Identity Disorder”  Archives of Sexual Behavior, DOI 10.1007/s10508-014-0278-2

Dennis McFadden, Edward G. Pasanen, “Spontaneous otoacoustic emissions in heterosexuals, homosexuals, and bisexuals” Journal of the Acoustic Society of America, http://dx.doi.org/10.1121/1.426845



Fun Reading:

All the Stars are Suns ebook completeSincerity Espinoza didn’t go looking for trouble, it found her. All she wants out of life is the chance to go to the stars but she is caught in a web of misunderstandings, political & legal maneuvering, and the growing threat of terrorist plots by religious fanatics. She has a secret that if found out too soon could mean not only her own death but the ruin of the hope for humanity ever going to the stars. But even amidst momentous events, life is still about the small moments of love, laughter, and sadness.   Available as an ebook at Amazon and Kindle Unlimited.

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Winds of Change

Posted in Female-to-Male, Science Criticism, Transsexual Field Studies by Kay Brown on November 6, 2014

critical-thinkingIn a very recently published paper (not behind a paywall, thankfully) the issue of changes in self-reported sexual orientation in transsexuals over their lifetime is explored.   The paper has some interesting data… and some very, very problematic data.  One of the problematic data points was the surprising number of self-reported, putatively, originally exclusively androphilic MTF transwomen whose sexual orientation changed to something else.  But… there seems be something… well… fishy about the data.  Take a look at this table:

Initial sexual orientation and history of transition in MtF: N= 70
Orientation               androphilic        gynephilic        bisexual        analloerotic (asexual)
N =                               18 (25.7%)           36 (51.4%)       7 (10%)         9 (12.9%)
age  (SD)                     41.6 (16.4)          51 (9.6)             36(10.8)        47.9 (15.9)
Age of onset              7.2 (3.9)             11.6 (9.9)         11.7 (7.3)       14 (5.8)
first  counseling      32 (13.8)            42.6 (11.5)        31.3(8.7)       39(17)
Transition                 36.4 (10.8)        45.2 (9.6)          33 (7.7)          40.7 (12.1)
HRT                              31.1 (13.8)        42.8 (11.8)        31.9 (9.5)       41.1 (17)
SRS                               35.3 (14.1)        47.5 (10.3)        36.2 (9.3)      34 (12.7)

Do you see it?  Hint:  Compare the ages and ages of transition for the “androphilic” and “bisexual” groups.  Ummmm… sorry guys, that data disagrees with EVERY other study ever done.  The mean age of transition for transkids is closer to age 20.  This was seen in the Nuttbrock and Tsoi studies, in which half of the androphilic MTFs who had started HRT had done so as teenagers… here the average age is 31 years old???  How is it that the “bisexual” group had begun transition, on average, three and half years before the “androphilic” group?  And somehow the “androphilic” group had SRS before beginning transition???  WTF!?  NOT!  Something appears to be very wrong with the data.  The so called “androphilic” group in this study is essentially identical with the “bisexual” group.  So what’s going on?  Can we say, “Social Desirability Bias“?  It looks like there are no actual, genuinely, exclusively androphilic transwomen in this study sample… not even one.

The study suggests that five of the eighteen putatively originally androphilic transwomen had changed their sexual orientation to bisexual, gynephilic, or “unknown”.  I have another interpretation… these five individuals simply admitted to actually having always been non-exclusively-androphilic, finally acknowledge it, as they realized they didn’t have to keep up the pretense.

The rest of the study makes more sense, as six of the 36 of the originally gynephilic identified transwomen reported a shift to bisexuality and androphilia.  This sort of shift has been widely reported before.  Of course, these shifts are generally recognized to be a result of interpersonal autogynephilia,

“Autogynephilic MtF transsexual persons often report the fantasy of sexual intercourse as a woman with a man, that was repeatedly described as faceless and abstract. Yet this pseudoandrophilia has to be distinguished from genuine androphilia or homosexuality in MtF, or as Blanchard points it: ‘‘the effective erotic stimulus, however, is not the male physique per se, as it is in true homosexual attraction, but rather the thought of being a female, which is symbolized in the fantasy of being penetrated by a male. For these persons, the imagined – occasionally real – male sexual partner serves the same function as women’s apparel or makeup, namely, to aid and intensify the fantasy of being a woman’’. Similarly, one of our participants that formally reported a change of sexual orientation from gynephilia towards androphilia stressed that ‘‘I always wanted to experience sexual intercourse as a woman but I did not know what to do with my male body before the hormone treatment. I hated male bodies in general before’’. In this case a reported change in sexual orientation from gynephilic to androphilic can be attributed to autogynephilic fantasies.”

The more interesting data in this study is all about the FtM transmen, about which we have far fewer studies.  Of six originally androphilic FtMs, four of them experience a shift to being gynephilic during transition… and of the 33 originally gynephilic six experience a shift to being androphilic or bisexual.

“In gynephilic FtM a reported change of sexual orientation was less frequent. Six gynephilic FtM reported a change of sexual orientation towards bisexuality and androphilia in the present study. This may in part be explained by the fact that androphilic sexual behavior is complicated for FtM. Sex with male partners can induce intense gender dysphoria by being penetrated as a woman although feeling as a man. One participant in the study of Rowniak and Chesla stated that he didn’t like being ‘‘feminized in bed’’ and others used the description that they were unable to have sex with men ‘‘until they were a man’’. Thus in these 6 participants androphilia may have been the original sexual orientation that became possible only after transitioning. In this case we wouldn’t expect a genuine change of sexual orientation in these gynephilic FtM transsexual persons.”

I was friends with an FtM who stated exactly the same thing… that he ‘identified’ as and participated in the lesbian community because lesbians would let him be butch, but straight men wouldn’t.  As a gay identified FtM, he could finally be both butch and express his native androphilia.  He was in fact, autoandrophilic.  (See my essay on autoandrophilila in FtMs.)

It is gratifying that the authors recognize the weaknesses of their current study and make some recommendations for future studies,

“Self-reported sexual orientation studies have further been reported to be interfered by the fact that some persons do not answer the question truthfully. Some transsexual people for example may want to present themselves as particular feminine (MtF) or masculine (FtM) and thus ‘‘classical’’ transsexual persons.  Participants in the present study might have biased their reports on purpose or unwittingly towards a more gender-typical presentation. This may also involve worries on denial of sex reassignment surgery. We feel that attempts to minimize such worries are important in future studies. We also suggest that researchers should explicitly ask for autogynephilic and autoandrophilic sexual orientation.”

Further Reading:

Essay on Pseudo-Androphilia in Autogynephilic MTF transsexuals


Matthias K. Auer, Johannes Fuss, Nina Hohne, Gunter K. Stalla, Caroline Sievers, “Transgender Transitioning and Change of Self-Reported Sexual Orientation”



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Autistic Sky

Posted in Brain Sex, Confirming Two Type Taxonomy, Female-to-Male by Kay Brown on September 21, 2014

shrinking brainFor the past several years, evidence has been accumulating that there is a fairly high comorbitity between transsexuality / transgenderism and the autism spectrum.  Interestingly, and perhaps not totally surprisingly, among MTF transwomen, it appears to be exclusively found in the non-exclusively androphilic population.  This fits the Freund/Blanchard taxonomy and more importantly, Blanchard’s prediction that “non-homosexual” (with respect to natal sex) MTF transwomen would exhibit neurological / brain differences from control males but these differences would NOT be a shift toward female like brains.

Autism and autism spectrum disorders are found in four to five  times as many men as women.  There are a number of theories as to why this happens, including the rather intriguing “hypermasculine brain hypothesis”, in which a link between the slight differences between men and women, as groups, having different cognitive and social behaviors and the apparent similarity, or rather, exaggeration of these differences between men and women, found in those on the autism spectrum.  If autism is a form of hypermasculinization, it would not surprise us to learn that FTM transmen were more autistic-like than most women… and that is what one group of researchers found.

Using a 50 item, Likert scored, instrument called the Autism Spectrum Quotient (AQ), Jones, et Al., found that FTM transmen as a group, scored 23.2, higher than control women AND men!  This puts about half of the FTM onto the high functioning autism spectrum!!   (The lower AQ cut-off for ASD is 23.)  Non-exclusively-androphilic transwomen scored essentially the same as the control men, while exclusively androphilic transwomen scored essentially the same as the control women, and definitely (statistically significant: p<0.03 ) below both the control men and non-androphilic transwomen.

Group:               Men                  Women       FTM                 Non-Androphilic           Androphilic
.                                                                                                     MTF  N=129                   MTF N=69

Score (SD):       17.8 (6.8)        15.4 (5.7)     23.2 (9.1)        17.4 (7.4)                         15.0 (5.6)

The implication is clear, FTM’s are masculine, perhaps even hypermasculine, while the data also supports the Freund/Blanchard two type taxonomy for MTF transwomen.  In the discussion section of the paper, the authors remarked,

“Interestingly, with the 198 transwomen group, there were 6 individuals (i.e. 3%) with a diagnosis of AS. This rate is about 3 times as many as in the general population.”

These authors didn’t state what the sexuality of the six AS individuals were; but if they conform to the greater likelihood that they were non-androphilic, found in other papers, the incidence rate for such non-androphilic transwomen would be closer to five times the rate found in the general population, however, that is only about twice as high as that found in the male population.

(Addendum: 1/21/2017:  Looking at the data again, this time from the perspective of effect sizes with respect to men vs. women and non-androphilic vs. androphilic aids us in understanding how important this difference is.  First, the effect size between men and women is 0.38 a modest but still very noticable difference in the populations.  Now, let’s look at the diffence between non-androphilic and androphilic at 0.37, nearly identical to the difference between men and women.  So, lets compare the difference between men and non-androphilic tranwomen at 0.06 which is tiny.  And similarly, when we compare between women and androphilic transwomen it is only 0.07 which again is very tiny.  That is to say, these statistical tests shows that the difference between men and women is the same size as between non-androphilic and androphilic transwomen, while there is effectly no difference between men & non-androphilic and women & androphilic transwomen respectively.  That is to say, that non-androphilic transwomen are identical to men in general, while androphilic transwomen are essentially the same as women in general.  Further the difference between the two types of transwomen exactly matches the difference between men and women, which strongly supports the Two Type Taxonomy.)

Further Reading:

Autism and Transgender


Jones, et Al, “Female-To-Male Transsexual People and Autistic Traits”, J. Autism Dev. Discord. DOI: 10.1007/s10803-011-1227-8

Annelou L. C. de Vries, Ilse L. J. Noens, Peggy T. Cohen-Kettenis, Ina A. van Berckelaer-Onnes. Theo A. Doreleijers, “Autism Spectrum Disorders in Gender Dysphoric Children and Adolescents” Journal of Autism and Developmental Disorders (2010)



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Drum keeps pounding… ♫♫

Posted in Brain Sex, Female-to-Male by Kay Brown on April 13, 2013

♫♫…rhythm to the brain…♫♫

shrinking brainData keeps coming in regarding brain imaging studies showing differences between MTF and FtM transsexuals and control males and females.  The question still remains, what does it mean?  Two studies, by two different groups, have measured the cortical thicknesses of transwomen before beginning HRT, to ensure that they are measuring potential organizing effects of endogenous hormones, or other effects, without the confounding activational effects of HRT.  However, the two studies looked at the two different MTF populations.  One, the Zubiaurre-Elorza paper examined only androphilic transwomen (N=18). Given that this group came from Spain, which, as Lawrence demonstrated, has a very low Hofstede Individualism index which is correlated with low percentage of gynephilic transwomen, these 18 were likely to have accurately reported their sexuality as exclusively androphilic.   While the Luders study, as an earlier study reported, examined both gynephilic (N=18) and self reported androphilic (N=6) transwomen.  Given that we know from many other studies of transwomen in high Hofstede Individualism societies, and the fact that the youngest of the Luders group was 23, we would expect that not all six of those who reported that they were androphilic were exclusively so.  In fact, I doubt that more than one or two at most is exclusively androphilic, if any.  Thus arises the question, can we use these two studies to get an early test of Blanchard’s prediction that “non-homosexual” transwomen would show brain difference from controls, but not a shift towards the female typical while the “homosexual” will show just such a shift?

First, some background, since I know that not all readers will be thoroughly up to date on the hypothesis being tested, nor the relevant data supporting it.  I recommend reading the FAQ on the is blog before continuing to read this blog entry, as a starting point.  Given that there is now mountains of data supporting the hypothesis that there are two types of MTF tranwomen, one autogynephilic (AGP) and non-homosexual (with respect to natal sex) and one that is non-autogynephilic and exclusively homosexual (HSTS); and that AGP transsexuals were behaviorally masculine since early childhood, and often even after transition and SRS, while HSTS transwomen had been remarkably feminine in behavior, and often in appearance, since early childhood, Blanchard made the prediction that brain studies would show that BOTH populations would be different than control males, but in different ways.  He further made the prediction that HSTS brains would be shifted toward the female morphology in sexually dimorphic areas of the brain, while AGP transsexuals would not.

This prediction is in opposition to the so called, “feminine essence” hypothesis, which is generally popular among AGP transsexuals, in which they posit that despite their obvious lack of naturally feminine behavior, they are still neurologically “female-like”, at least in some important way.

So far, the very limited data supports Blanchard’s hypothesis and NOT the “feminine essence” hypothesis.  Also so far, no formal study has been conducted that would specifically test these two hypothesis together.

I stated earlier that I didn’t believe that the Luders study group contain many exclusively androphilic (HSTS) individuals.  The reasons I believe this are several fold.  First, they collected most of their group by soliciting via transgender organizations.  As was shown in the Veale study on transsexual sexuality, soliciting through such organizations tends to reach only AGP individuals, as HSTS youth do not tend to be members of such.  Second is the age range of the study entire group.  The youngest was 23.  This would be very unusual for a group of that had a sizable portion of HSTS individuals, given that the median age of transition is 20 years old and the top end is typically 25 years old, and even that old is very rare.  If all six HSTS individuals were 23 to 25, this would be odd.  Also given that the mean age of the entire group is 45, which is a bit higher than the typical mean transition age for a group consisting of only AGP transwomen, this would suggest that there were not many of the total group that was in their early 20’s, certainly not six out of 24 individuals.  Thirdly, as Lawrence has shown, in two different study groups, significant numbers of individuals who claim to be androphilic are inaccurately reporting their sexuality.  Added together, I don’t believe that more than one or at most two, of the Luders study group was actually exclusively androphilic.  I suspect that none of them were.

As we explore the data from these two papers, we need to keep in mind that brains, like bodies, come in different shapes and sizes, more or less.  That is to say, although there are differences between male and female brains, on average, it is difficult to point to a part of the brain and say with absolute certainty, this is a male brain vs. a female brain.  Another thing to keep in mind, if we have a mix of two populations, both may have differences unique to each population… and that when mixed, both of those differences will be detected when we average the data, blurring and blunting the differences, but we should still be able to statistically see a signal in the data, provided we have enough data.

So, lets examine the data.  First, if we look at the high level view, it would appear that there are indeed differences between the control men and women and androphilic transwomen.

Zubiaurre Brain ScansIn general, female brains have thicker cortices (CTh), at least in some areas, as the comparison between male and female controls shows.  As we had expected, MTF  transfolk are different than male controls, but FtM are not that different from female controls.  The authors described the results thus,

“We have found that control females have greater CTh compared with control males in the frontal and parietal regions; in contrast, males have a larger putamen volume than females. With respect to the transsexual groups, we observed that FtMs have greater CTh compared with control males in the parietal and temporal cortices and did not differ from control females. However, FtMs have a larger right putamen than female controls. On the other hand, MtFs did not differ from control females in CTh and had greater CTh than control males in the frontal and occipital regions. In this group, no differences were found in the putamen. All these findings suggest that FtMs have a defeminized putamen, while MtFs have a feminized CTh.

With respect to the CTh of MtFs, we found that this group did not differ from female controls but did from male controls.  These findings suggest that MtFs follow the pattern of cortical thinning typically described for females. Whether the cortical feminization of MtFs depends on a differential cortical androgen receptor distribution, a different efficiency in the androgen receptors or other causes remains to be elucidated.  But what seems clear is that in MtFs the cortical developmental process is affected and follows the direction expected for females. This points out that the developmental approach could help to understand the etiology of transsexualism.”

Let’s compare these results with that of the Luders study, which is mostly (and perhaps entirely) non-exclusively androphilic, which being autogynephilic, Blanchard had previously predicted would show differences from control males, but not in the female like direction:

Luders Brain ScansAt first blush, we see that they are indeed, as predicted, different than control males.  Some areas of the cortices are thicker, but not the same regions as control females nor androphilic transwomen.  So, it would seem unlikely that these brain difference are caused by a feminization of the brain, given that the regions are not those found in control females.  But what does cause these particular differences?  While we might be tempted to conclude that this is caused by autogynephilia, it could also be caused by another attribute that is common in this population, higher IQ.  It has been noted that higher IQ is correlated with thicker cortices.

So where to do we go from here?  This visual comparison of the two studies can only be described as tentative.  But the need for such comparisons are clearly understood by these researchers, as the Zubiaurre-Elorza paper explained,

“On the basis of chromosomal sex and behavior, Blanchard and co-workers (Blanchard et al. 1987, 1989, 1996; Blanchard 1989; see also Smith et al. 2005) have proposed the existence of 2 types of MtFs: 1) MtFs that are attracted to males (“homosexual” transsexuals in Blanchard terminology), and 2) MtFs that are attracted to women (“heterosexual” transsexuals according to Blanchard). Further, Blanchard (2008) hypothesized that homosexual MtFs would differ from heterosexual males in brain sexually dimorphic structures, while in the heterosexual MtFs, the differences might not implicate sexually dimorphic structures. More recently, Cantor (2011) has noted that our findings on the white matter microstructure of (homosexual) MtFs (Rametti, Carrillo, Gómez-Gil, Junque, Zubiarre-Elorza et al. 2011) and that of Savic and Arver (2011) on the cortical volume of (heterosexual) MtFs would support Blanchard’s hypothesis. In the present report, we studied MtF transsexuals erotically attracted to males that show a feminization of CTh but not in the putamen.  …  Consequently, to verify Blanchard’s hypothesis would require a specific design that is beyond the scope of the present study.”

For more essays on trans-brains see Brain Sex.


Eileen Luders, et al., “Increased Cortical Thickness in Male-to-Female Transsexualism”
Journal of Behavioral and Brain Science, July 2011

Leire Zubiaurre-Elorza et al, “Cortical Thickness in Untreated Transsexuals”
Cerebral Cortex, August 2012

Katherine Narr, et al., Relationships between IQ and Regional Cortical Gray Matter Thickness in Healthy Adults
Cerebral Cortex, November 2006


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Curiouser and Curiouser…

Posted in Female-to-Male, Science Criticism by Kay Brown on February 18, 2013

… said Alice.

critical-thinkingIn a recent paper exploring the sibling sex ratio and birth order of transkids, several interesting new biodemographic findings were disclosed.  First, the already known surplus of older brothers of MTF transkids was observed, along with the fraternal birth order effect of having more older brothers than sisters.  But, curiously, these transkids also had more younger brothers than sisters!  The reason this is so startling is that we have no plausible conjectures on how this could come about, as we do the fraternal birth order effect.

Another curious item is that FtM transkids are more likely to be only children than one would expect by chance.  Blanchard does offer a possible conjecture that this may be an immune response, leaving the mother unable to conceive again.

This new finding in MTF transkids is further evidence that there may be more than one biological mechanism at play.

But to me, the most curious thing to note in this paper is the actual paper, who wrote it, and how it was edited.  It has the feel of having had sections written by different authors, who habitually use different terms for the same phenomena and populations.  As I had written in an earlier essay, those in North America preferred the term “homosexual transsexual” and those in the Netherlands preferred “Early Onset” transsexual.  This paper was co-written by Ray Blanchard, from North America, while the rest were from the Netherlands.  It would appear that both formulations were used in this paper, starting with “early onset” in the title then using “homosexual” in the abstract:

Several sibship-related variables have been studied extensively in sexual orientation research, especially in men.  Sibling sex ratio refers to the ratio of brothers to sisters in the aggregate sibships of a group of probands. Birth order refers to the probands’ position (e.g., first-born, middle-born, last-born) within their sibships. Fraternal birth order refers to their position among male siblings only. Such research was extended in this study to a large group of early-onset gender dysphoric adolescents.  The probands comprised 94 male-to-female and 95 female-to-male gender dysphoric adolescents. The overwhelming majority of these were homosexual or probably prehomosexual.  The control group consisted of 875 boys and 914 girls from the TRAILS study. The sibling sex ratio of the gender dysphoric boys was very high (241 brothers per 100 sisters) compared with the expected ratio (106:100). The excess of brothers was more extreme among the probands’ older siblings (300:100) than among their younger siblings (195:100). Between groups comparisons showed that the gender dysphoric boys had significantly more older brothers, and significantly fewer older sisters and younger sisters, than did the control boys. In contrast, the only notable finding for the female groups was that the gender dysphoric girls had significantly fewer total siblings than did the control girls. The results for the male probands were consistent with prior speculations that a high fraternal birth order (i.e., an excess of older brothers) is found in all homosexual male groups, but an elevated sibling sex ratio (usually caused by an additional, smaller excess of younger brothers) is characteristic of gender dysphoric homosexual males.  The mechanisms underlying these phenomena remain unknown.

The use of the term “homosexual” has often bothered many transsexuals, both autogynephilic and non-autogynephilic alike… but apparently it bothered at least one of authors of the paper as well,

(instead of ‘‘homosexual’’ transsexuals, we will refer to male-to-female transsexuals sexually attracted to men as androphilic MtFs, and to female-to-male transsexuals sexually attracted to women as gynephilic FtMs)

While I applaud the sentiment of using language that is more sensitive to the sensibilities and personal identities of transsexual people, the effort here loses its intended effect since all such males are still called “boys”, and such females are called “girls”, largely defeating the purpose.  Further, the authors simply did not maintain the usage of “androphilic” in preference to “homosexual” as later in the paper they write,

It was reasonable to assume that all or nearly all of the early-onset gender dysphoric boys in this study were, or would be, homosexual, and that nearly all of the control boys were, or would be, heterosexual;

So, it would appear that the final editor failed to clean up the language of the paper to make it consistent with a ‘politically correct’ terminology.  But this failure also allows us to unite the terms, making this paper a ‘Rosetta Stone” of research papers:

Homosexual = Androphilic (or Gynephilic for FtM) = Early Onset

Thus, this paper helps spell out, in an unambiguous manner, that the researchers are indeed talking about the same populations, and that there is now universal agreement that the Freund/Blanchard typology is correct.


Sebastian E. E. Schagen, Henriette A. Delemarre-van de Waal, Ray Blanchard, Peggy T. Cohen-Kettenis, (2012) “Sibling Sex Ratio and Birth Order in Early-Onset Gender Dysphoric Adolescents”


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Posted in Book Reviews, Female-to-Male, Science Criticism by Kay Brown on December 21, 2012

~LUCY!!!~  …Oops, I meant, ~Ethel !!!!~

Ethel Spector Person, of “Person and Oversey” fame, died on October 16th of this year.  Her obituary in the New York Times said that her work was influential in demonstrating that there was more than one type of transsexual.  To that, I would have to agree…

… but, I can’t agree that she was “totally right”, because, in fact, she was not.  To understand why, we need to examine both the times in which she worked, and her own words.

First, where she was right.  Ethel Person did correctly recognize that there were at least two types of transsexual.  She recognized that one type was related to transvestites, and had a transvestic career before seeking sex reassignment.  She described them quite well, when she stuck to pure observation.  She also discussed another type, that was related to homosexuals.  Here, she failed miserably.

Incredibly, she described both of these types as “secondary transsexuals”.  Why?

Why?  Largely because she too was caught up in the pseudo-science of psycho-analysis.  She accepted as revealed truth that sexuality developed during, and was shaped by, early childhood experiences, and not just a little bit,  but root and branch.  She can be forgiven for accepting such, since after all, so did everyone else during the middle of the 20th Century.  Today, with our knowledge of neurological correlates of sexual orientation, the fraternal birth order effect, and of epigenetics, it is easy to forget how even our recent fore bearers struggled to understand the likely biological origins of sexual orientation.

In her book, The Sexual Century, published in 1999, she recapitulated her earlier work.  In 1974, she theorized a “primary transsexual” would be an individual who had developed directly to being an asexual transsexual without having first been either homosexual or heterosexual transvestite.  This is because both homosexuality and transvestism, in her psycho-analytically informed world view, are both primary disorders, so– obviously, their transsexuality must be viewed as “secondary” to their primary disorder.  Thus we read,

Primary transsexuals, as we have seen, are essentially asexual and progress toward a transsexual resolution without significant deviation, whether heterosexual or homosexual.

This naturally begs the question, resolution of what?  The resolution of psycho-analytically hypothesized childhood sexual anxieties, of course.   It is interesting that in her book, a tiny print footnote appears on page 97, “… I no longer regard homosexuality as a disorder…”  So, perhaps we should forgive her for her earlier opinion?

Person’s “primary transsexual” is easily recognized today as being asexual autogynephilic transsexuals, as was specifically pointed out by Blanchard.  Her description is quite detailed and accurate, but her analysis is flawed in that she failed to note the autogynephilia driving them.

On another page, we read,

We have concluded from a study of female transsexuals that there is no female equivalent of primary male transsexualism.  In our opinion, the transsexual syndrome in women develops only in the homosexuals with a masculine gender role identity.  Female transsexualism, therefore, can be classified as another form of secondary (homosexual) transsexualism.

In her equating FtM and MTF transkids as being alike, we see that she was quite right, despite the silly notion of “secondary transsexualism”.  But, as alluded earlier, in her case histories she included descriptions of two individuals who she put forward as exemplifying male “homosexual transsexuals”, which as a modern reader will recognize, one was clearly not, while the other was what Kiira Triea so aptly described as an “in-betweenie”, a 25 year old individual that was right at the borderline between a classic transkid and a feminine gay man / drag queen, and unlikely to actually transition.  This may be understood in the context of presenting not a middle-of-the-road example or two, but the most dysfunctional?  After all, if one is a psychiatrist (as Dr. Person was) describing the course of a disease, one may present a particularly serious case so as to make its characteristics abundantly clear, rather than than a mild one?  If so, she misjudged.  From her book:

Case 1. C. is a fat, effeminate 32 year-old man who lives with his parents.  He is compliant, nonassertive, and unable to mobilize much anger.  Despite these inhibitions, he is engaging, affectively responsive, and easy to talk to .  His adaptive competence is of a very low order.  Although extremely bright and articulate, he failed to complete high school, dropping out in his senior year.  He has worked only a total of two years in his entire life.  His mother has always slipped him money, while both pretend to the father that he is working.  …  C. has been an exclusive homosexual as far back as he can remember.  He now wants sex reassignment so that he can marry his current lover and live with him as his wife.   …

…We interviewed C.’s mother who confirmed the familial history.  …  She had always known of C.’s homosexuality and fully accepted it, but refused to acknowledge his wish for a sex change.  …  As she saw it, his sole problem was his inability to work.

C. was an effeminate child.  He played with girls and pursued girlish interests.  He cross-dressed regularly with parental approval from early child-hood until the age of fifteen.  The cross-dressing was theatrical and used to enhance C.’s fantasies of being a girl.  It was never erotic, as in the transvestite, nor did it provide a feeling of comfort, as in the primary transsexual.  His parents thought it was amusing that they often asked him to entertain.  Once, when he was seven, they took him to relatives for Easter dinner dressed as a girl.

C. began a very active and pleasurable sex life when he was twelve.  He engaged in various homosexual activities with peers, older boys, and adults.  His sexual preference is passive anal intercourse, although he will reluctantly engage in other sexual transactions in order to please a partner.  In such circumstances, he is capable of assuming the active role, but does not enjoy it.  His sexual relationships have been mostly transient contacts with partners picked up while cruising.  Prior to his present involvement, he had only one long-term affair.  This occurred ten years ago and lasted for one year.  C. was so upset when the affair ended that he became suicidal and had to be hospitalized.

After his release, he hung around with a drag crowd for about six months.  Once again he cross-dressed, but only in public to be seen, never in private.  …  He received no narcissistic reinforcement as a woman since he lacked beauty, and the masculine homosexuals whom he was really after paid little attention to him since most of them wanted another man, not a drag queen.  Thoroughly discouraged, C. gave up drag and returned to his previous existence, with its characteristic cruising. …

… Last year he went to Spain and met a presumed heterosexual with whom he lived.  He engaged in face-to-face intrafemoral intercourse with this lover and fantasized himself as a woman.  For the first time in his life he began to think seriously of sex reassignment:  “I’ve known about transsexualism since Jorgensen.  I could relate to this guy in Spain better if I were female.  He wants me to stay in the the house and play the whole thing, be subservient.”   …   He is still hesitant, however, because he is skeptical that the lover will, in fact, marry him. …

This man is, in the common vernacular, a “Loser” and a “Bum”.  He is an unattractive 32 year old gay man who has only recently thought of sex reassignment, and then only because a lover he met while on vacation has promised to marry him if he does.  Ummm… yeah… and the check is in the mail!  This man is representative of transkids?  Seriously Ethel?  Seriously?

~ETHEL !!!! You’ve got some ‘splainin’ to do!!!~



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The Age of Innocence

Posted in Female-to-Male, Transgender Youth, Transsexual Field Studies by Kay Brown on February 28, 2011

At what age should transkids start HRT?

OH, if you were a little boy,
.  And I was a little girl –
Why you would have some whiskers grow,
.  And then my hair would curl.
Ah! if I could have whiskers grow,
.  I’d let you have my curls;
But what’s the use of wishing it –
.  Boys never can be girls.
–Kate Greenaway, Marrigold Garden, (1885)

For physicians and other health care providers, an over-riding concern is to “do no harm”.  One of the fears for such care providers is that of starting a course of treatment intended to treat a condition, only to discover that they misdiagnosed the patient and gave a treatment that not only was unneeded, but potentially harmful.

In the case of trankids, both MTF and FtM, the sooner one can begin hormonal & surgical treatment and social support interventions to allow them to successfully transition into the appropriate gender/sex role so as to take advantage of the normal adolescent physical and social maturation process along side their peers, the better the long term outcome.

But, as the very recent Steensma study, as well as many before it, shows, not all gender atypical children will be gender dysphoric, and not all gender dysphoric children will persist as such into their teen years.  Thus, the study was conducted in the hope of finding differences between persistors and desistors, so that clinical treatment decisions can be made as early as possible.  The earlier one can separate the two, the earlier one can begin to treat the transkids, while letting non-transsexual teens grow up naturally, without potentially harmful iatrogenic trauma.

Because healthcare providers have not been able to accurately predict which gender atypical / dysphoric children will persist, a number of practitioners have begun recommending and using a puberty blocking protocol, under a harm reduction model in which the persistors are protected from the harmful effects of their endogenous hormones, while refraining from iatrogenic injury from exogenous cross-sex hormones in those who will desist from their earlier gender dysphoria.  The current recommendation is that such puberty blockers be used until the individual is 16 or even 18 years old, at which time, if he/she is still a persistor, they may be switched to cross-sex hormones, while the desistors may terminate the puberty blocking protocol at any time.  (There is a built in bias for desistors and against persistors in that desistors can begin a prefered hormonal protocol, simply by stopping the puberty blockers, but persistors must wait and “prove” to healthcare workers that they are ready.)

The problem with this protocol is two fold.  First, it is not without its own potential for iatrogenic harm in that delaying puberty reduces the eventual strength of the bones in adulthood.  This may not be immediately harmful, but those children will someday be older adults, whose bones will be more prone to breaks.  Second, for MTF transkids, delaying puberty means that they will continue to grow taller, potentially reducing their ability to pass successfully as female.  This effect may however be welcomed by the FtM transkids, but their desisting female peers may not feel the same.

Another problem with this protocol is that it is very expensive, far more expensive than cross-sex Hormone Replacement Therapy (HRT). For those who live in countries who do not have a generous state provided health plan, this may be a deal breaker.

So, for health care providers and parents alike, it may be better if they can accurately predict who will desist and who will persist.  Getting this data is the object the Steensma study.  The Steensma study is short on statistics, but what they do have is remarkable:

.                                Total group       Persisters     Desisters
.                                    (N = 53)            (N = 29)       (N = 24)

Natal sex
% (N) Boys             56.6 (30)          58.6 (17)      54.2 (13)
% (N) Girls              43.4 (23)          41.4 (12)       45.8 (11)
Age at childhood
M (SD)                   9.41 (1.46)*     9.92 (1.26)    8.81 (1.47)
Age at follow-up
M (SD)                 16.11 (1.70)     16.14 (1.84)   16.07 (1.54)
Full-scale IQ
M (SD)            100.26 (12.82)    98.83 (12.28)  102 (13.50)

* Significant difference observed between persisters and desisters in age at childhood assessment (t(51) = 2.968, p < .05), Cohens d = 0.81 .

For starters, the IQ of the persistors is 98.83, essentially average.  Although this is combining FtM and MTF, the number agrees with my earlier estimate of 98.6 for the MTF HSTS population.

But, the more important data is that there is a difference between the ages of childhood assessment, the age at which their parents brought them to a clinic for evaluation.  (The difference being on average a little over a year, or over 10% of their age, and a very large effect size of d = 0.81 )  But, the study makes it very clear that there was very little difference between the two groups in their early childhood gender atypicality.  So why is there this difference?  Why would the parents of persistors wait longer than those of desistors?

Because they don’t!  It wasn’t that parents of persistors waited longer, it was that many desistors, desisted at an earlier age, such that their parents never brought their children in for assessement.  As they get older, fewer and fewer parents of desistors would bring in their children.  But, the persistors would continue to be brought in at later and later ages.  Indeed, the authors specifically stated that from the interviews, the desistors clearly articulated that from age 10 to 13 were critical for their change in gender dysphoric feelings.  While, for persistors, that same age only confirmed and strengthened their feelings.  Thus, both interview report and the statistics agree that something special seems to be happening starting at around the age of ten or even a little younger.

Starting around the age of 10, and for the subsequent years, the persisters indicated that their crossgender preferences and behaviour and their gender identity remained stable, but that their dysphoric feelings intensified. The intensification of gender dysphoria was attributed to three factors; (1) Certain changes in their social environment, (2) The anticipation of and/or actual physical changes during puberty, (3) The first experiences of falling in love and discovering their sexual orientation.

The authors, in focusing on what the teenagers said were influential, may have missed a critical factor.  What’s so special about the age of ten?  This is well before puberty.  The authors focused on changing social factors, but could it be that biology is the important factor?  McClintock and Herdt point out that sexual attraction is first noted well before our classic definition of puberty, that of the maturation of the gonads and subsequent increase in testosterone, estrogen and progesterone.  Instead, other hormones start earlier, typically around ten years old.  And this is the age at which one’s sexuality begins to be recognizable.

With regard to sexual attraction, all persisters reported feeling exclusively attracted to persons of the same natal sex, which confirmed their gender identity as they viewed this attraction as a heterosexual attraction. They did not consider themselves homosexual or lesbian.

For the desisting boys, some came to recognize that they were gay or bisexual, essentially confirming the results of many other studies which have shown that gender atypicality in boys is highly corralated with homosexuality.  However, a number of the boys self-identified as heterosexual, even though they also recognized some same sex attraction.

For the girls, all of the desistors had become aware of the fact that they were heterosexually attracted to boys and wanted to be sexually attractive to boys.  Thus, they were the classic tomboys who grow up to be straight women.  But the persisting girls were all attracted to girls.

Thus, this study showed that the key difference between persistors and desistors among female bodied gender atypical / dysphoric individuals was sexual orientation, but among male bodied, it was not as clear cut, desisting boys included both gynephilic and androphilic sexual orientations.  However, what is clear is that persisting boys are all clearly unambiguously androphilic (HSTS).  Persistors will demonstrate same sex attraction, while desistors may or may not.  Thus opposite sex attraction is a key exclusionary sign for persistors.  Although we still would have some desistors who don’t show this sign, we have at least conclusively identified some.

Further, none of the study group was autogynephilic.

This last point is important.  Although many autogynephilic adults report having been gender dysphoric as children, it is rare, though clearly not unheard of, for them to have been noticed as such as children.  They are the “non-aparent” population as children.  However, for the HSTS population, of both sexes, MTF and FtM, their gender dysphoria was accompanied by obvious gender atypicality.  Since obvious gender atypicality is not found in autogynephilic boys, who are universally gynephilic, we can safely say that anyone who is obviously gender atypical and sexually attracted to the opposite sex is not going to be a persistor.

Another point can be clearly found in the Steensma study is that the developmental process, what ever it is, for desistors, is finished by age 14.  If a gender atypical 14 year old is still gender dysphoric and wishes to begin hormones and transition, we can be reasonably certain that he or she will not change his/her mind later.  Thus, based on the evidence, we can safely begin such interventions.  The sooner the better.


Transkids after transition

Transkids after transition

From the evidence, we draw the conclusion that for obviously gender atypical / dysphoric children, waiting until one is 16 or 18 years old to end puberty blocking protocols and beginning HRT is unwarranted and ill-advised.  Instead the evidence points to the age of 14 as the latest that HRT may safely be begun with little risk of iatrogenic injury to desistors.  Indeed, the evidence suggests that carefully evaluated, many of the desistors may be excluded by age ten to twelve.  Another point to come of these studies is that anatomic dysphoria (discomfort with genitalia, etc.) is correlated with persistence.  Thus, if delaying puberty is chosen, it should not be continued past the 14th birthday, and given proper screening, may be ended earlier, to switch to HRT.  For both cost and health reasons, it may be best to start on HRT for those who clearly fit the profile of a transkid, who request and understand the consequences of HRT, as soon as would be indicated for their gender of choice.  That is to say, that for MTF’s, HRT should begin at age 12, and for FtM, at around age 14, mimicking the natural maturational process for each target sex.

Addendum 2/23/2012:

If you are a young teen, finding this post:  Welcome!  To answer some questions.  Yes, you can start blockers, maybe with low dose HRT, as young as 10 years old, but should start with very low doses, gradually increasing to the recommended level for teenagers as you reach 12-14 years old.  Of course, you would need either your parents permission, or find a youth clinic that understands transkids’ issues, who would prescribe blockers & HRT on a “harm reduction model” .  (Seriously, that’s the magic words, “harm reduction”… as in… “I’m going to get hormones on the street if I don’t get them here.”)  Good luck!

Addendum 6/1/2012:

Please read my Advice to Parents of Transgender Children

Addendum 12/29/2012:

Please read my Advice to Transgendered Teens

Addendum 4/1/2021:

A newly published study, by Singh, but with individuals who had gone to a Toronto clinic years earlier (and thus evaluated with older criteria that we know are a bit loser than today’s) has data on persisting and desisting male youth.  As before, we see that most of them turned out to be primarily androphilic with the persisters being universally so.  And again, we see a difference in the age of evaluation with persisters being older at 8.85 years and the androphilic desisters being 6.96 years old (Cohen’s d = 0.84 a ‘large’ difference).  Interestingly, there were a number of gynephilic desisters in the study who were also younger in age at evaluation at 7.49 which is very similar to the desisting androphiles (d = 0.2 a ‘small’ difference).  Note that the difference, of d = 0.84 is essentially the same as the d = 0.81 found in the Steensma study.  Thus, the characteristic difference has been replicated and may be trusted.

Another difference was found in IQ.  Desisters were more intelligent than average at 110 while the persisters had the expected population average of 99 (100 is the population average, so this showed no significant difference).  Thus, there seems to be a selection effect that smarter kids are being brought in by their families at a younger age by families with higher socio-economic status (which correlates with higher IQ that runs in families).  Perhaps this is because they over-react to mild gender atypicality?  The authors of the study suggested that it was the fault of the poorer parents, “delaying” instead.  I stand by my assertion that it’s based simply on the fact that desisters desist and are no longer brought in for evaluation.

As seen in other studies, the persisters were more gender atypical and gender dysphoric at evaluation than desisters.

Further External Reading:



Thomas D. Steensma, Roeline Biemond, Fijgie de Boer and Peggy T. Cohen-Kettenis, “Desisting and persisting gender dysphoria after childhood: A qualitative follow-up study”

Vicente Gilsanz, James Chalfant, Heidi Kalkwarf,Babette Zemel, Joan Lappe, Sharon Oberfield, John Shepherd, Tishya Wren, Karen Winer, “Age at Onset of Puberty Predicts Bone Mass in Young Adulthood”

Martha K. McClintock and Gibert Herdt, “Rethinking Puberty: The Development of Sexual Attraction”

Madeleine S.C. Wallien, Peggy T. Cohen-Kettenis,”Psychosexual Outcome of Gender-Dysphoric Children” Journal of the Academy of Child and Adolescent Psychiatry (2008)

Annelou L.C. de Vries, Jenifer K. McGuire, Thomas D. Steensma, Eva C.F. Wagenaar, Theo A.H. Doreleijers, Peggy T. Cohen-Kettenis, “YOUNG ADULT PSYCHOLOGICAL OUTCOME AFTER PUBERTY SUPPRESSION AND GENDER REASSIGNMENT” Pediatrics (2014)

Kelly Winters, “Methodological Questions In Childhood Gender Identity Desistence Research”  Blog Link

Brik, T., Vrouenraets, L.J.J.J., de Vries, M.C. et al. Trajectories of Adolescents Treated with Gonadotropin-Releasing Hormone Analogues for Gender Dysphoria. Arch Sex Behav(2020).  https://doi.org/10.1007/s10508-020-01660-8

Singh D. et al., “A Follow-Up Study of Boys with Gender Identity Disorder”, Frontiers in Psychiatry, https://doi.org/10.3389/fpsyt.2021.632784 


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Seeing the world in Grey and White…

Posted in Brain Sex, Female-to-Male by Kay Brown on January 8, 2011

…brain matter

It is exciting to see that neuroimaging science is getting to the point where we needn’t wait until subjects are dead before we can examine their brains in better detail. Exciting recent developments include a pair of papers from Spain in which Diffusion Tensor Imaging (DTI), a form of MRI, was used to compare FtM and MTF transsexuals to control men and women. The results were that transsexual brains exhibit white matter features, that are known to be sexually dimorphic, mid-way between male and female morphologies. The studies are doubly interesting, because the subjects had not yet begun exogenous Hormone Replacement Therapy (HRT) eliminating the possibility that the features were the result of activating effects of HRT.

So, does this mean that we have proven that transsexuals have “intersexed brains”?

Yes… and at the same time… No.

First, in the case of Female-to-Male transsexuals, it has always been noted that the majority were both gynephilic and masculine behaving since early childhood. So, these results are hardly surprising. However, the exact same thing can be said for butch lesbians, who do not necessarily identify as men. So, if we were to image the brains of a population of such butch lesbians, would we see the same masculinized neurological features? Would we see that transmen were more masculinized than butch lesbians, who would in turn be more masculinized than average lesbians? Also, if we imaged the brains of a population of gay identified transmen, would we then see that they do not share such masculinized features? I’m betting we would, and eagerly await the results of such imaging.

Which brings us back to the Male-To-Female subjects in the Spanish DTI study. As Lawrence has pointed out, different cultures have varying prevalence of non-homosexual transsexuality. Spain is one of those cultures where very few of the MTF transsexuals are non-exclusively-androphilic, with only 9% of the MTF transsexuals being non-exclusively-androphilic. In this case, as reported in the paper, there were no such non-exclusively-androphilic subjects. All were described as “early onset” and androphilic. Thus, this study only tells us about one type of transsexual.

Sadly, there wasn’t a gay male control group. It would have been interesting to see if the MTF transsexuals exhibited the same or more feminization (non-masculinization) of these sexually dimorphic brain structures. One hypothesis regarding exclusively androphilic transsexuals is that they are the extreme end of a range of feminine (hypo-masculine) homosexual males, who find that their innate femininity sufficient that living life as women is a better rational as well as emotional choice. (That is to say, that they are so feminine, like women, that they are women at heart.) I eagerly await DTI imaging studies that can test this hypothesis.

Now that we have DTI data on the HSTS population, we must gather data on the non-HSTS population to see if they do or do not exhibit such partially feminized (hypo-masculinized) features. Once again, we have no data that would show, conclusively, one way or the other, that both types of MTF transsexuals share neurologic features that would serve as the basis of a unifying etiology.

It’s not much of a limb to go out on, given the very strong data that shows that there are two types with two separate etiologies, but I’d be willing to bet that that when we do have such DTI images of gynephilic MTF transsexuals, that they will be no different than typical straight men, at least with respect to these particular sexually dimorphic features.

Which brings us to another study (Luders) looking at grey matter instead of white sexually dimorphic brain structure differences between MTF transsexuals and control men and women, this time one that suggests that for a very localized spot, they found a feature in MTF transsexuals that is different and possibly ‘more feminine’ than male controls. However, globally, the MTF brains were shown to more like men, and if anything, perhaps more masculine than control men, as they showed less grey matter then men, who show less grey matter then women. But one spot, the right putamen, is definately different in MTF transsexuals than in control men, showing more grey matter, in fact, more grey matter than the control women.

Sadly, as the researchers themselves point out, they may have included both exclusively androphilic and non-exclusively androphilic transsexuals without analyzing them separately; Of the 24 subjects, six self-reported to be androphilic and 18 reported to be gynephilic. It is heartening that the researchers recognize that in the future, they need to make the distinction and analyze the two types separately. Further, as these TS folk are pre-HRT, their ages may be used as a statistical proxy for our purposes, as MTF transkids usually (>90%) begin transition and HRT before age 25: the mean age was 47 years old, standard deviation of 13 years, with the range from 23 to 72. We know from Lawrence’s re-sorting from the Smith data set that a fair number of MTF transsexuals who self-report being androphilic are not exclusively so, thus it is likely that less than six of the subjects are exclusively androphilic.  A little math will show that that with a normal distribution, only one of the 24 subjects would have been expected to have been 25 or younger, so this 23 year old may be the only one.  Therefor, as Luders et al did find a statistically significant signal, we might infer that it is more likely that it came from the non-exclusively androphilic type, and thus likely also autogynephilic.

While it may be tempting to declare that this feature found in the right putamen proves that MTF transsexuals, in-fact, that gynephilic MTF transsexuals, have a part of their brains that is femininized, this conclusion should not be drawn from this data, at this time. Although it may be a marker of transsexual neurology, it may not be from a feminization of this region, especially given that it shows more grey matter than both control men and women. It may be a marker of an unusual neurological development altogether unrelated to sexual dimorphism. It may in fact be a marker for autogynephilia, or proneness to erotic target location errors. In fact, such a marker is expected to be found. We need further studies.

First, we need to compare the two types of transsexuals to test if this is a marker of a unifying neurological feature of transsexuality. Second, we need to compare both of them to individuals who are sexually aroused at the thought of becoming amputees, to test the hypothesis that this may be a marker of proneness to erotic target location errors.

But, in the mean time, the world is not so much to be understood as black and white, but shades of grey and white.

For more essays on trans-brains see Brain Sex.

Addendum 12/19/2011:

You may wish to read a new blog entry on an additional paper on this topic.


Rametti G, Carrillo B, Gómez-Gil E, Junque C, Segovia S, Gomez A, Guillamon A., “White matter microstructure in female to male transsexuals before cross-sex hormonal treatment. A diffusion tensor imaging study.”

Rametti G, Carrillo B, Gómez-Gil E, Junque C, Zubiarre-Elorza L, Segovia S, Gomez A, Guillamon A., “The microstructure of white matter in male to female transsexuals before cross-sex hormonal treatment. A DTI study.”

Luders E, Sánchez FJ, Gaser C, Toga AW, Narr KL, Hamilton LS, Vilain E., “Regional gray matter variation in male-to-female transsexualism.”



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