sillyolme

Why Does Typology Matter to Medical Professionals?

(Somewhat related post & another)

Or, does typology have any medical bearing on treatment? It seems the answer is a resounding no according to a litany of research on the topic.

A 2016 study of Chinese trans individuals (Yang et. al) found that sexuality has essentially no correlation with PCS (physical component summary) and MCS (mental component summary) of the measured quality of life. Table 3 indicates that the associations between orientation and PCS ranged from -0.005 to 0.098, all of which were far below statistical significance. It was the same for MCS; a range from -0.012 to -.121 that did not achieve statistical significance (the most accurate model has a correlation of -0.066). Now of course we could attribute this result to sample bias, statistical error, or using faulty statistical models, but luckily there are a host of other studies that replicate the finding.

Meier et. al 2013 found no differences in mental health variables between FtM individuals, other than a minor difference in anxiety (the only difference was between androphilic and ambiphilic individuals, all other comparisons were statistically insignificant). We should also note the interesting change in sexual orientation reported by FtM individuals during the process of transition (which I’ll eventually get around to a post on).

Nieder et. al reviewed the entire literature and found just 10 studies (which is sufficient for a literature review in the field) reporting on the association between sexuality and transition-related outcomes. Just one of these studies reported a difference;

Given the intense debate surrounding the predictive, outcome-related value of sexual orientation after transition-related interventions (Lawrence, 2014; Veale, 2014, 2015), it seems remarkable that out of 10 follow-up studies (Table 1), only one reported or found a significant association according to the outcome measures between groups based on sexual orientation at all (Wierckx et al., 2014). They found that trans women who are attracted to men (unfortunately mostly referred to as ‘homosexual male-to-females’, which pertains to the sexual orientation according to the sex assigned at birth) had higher sexual desire compared with trans women who are attracted to women

and

Further, sexual orientation was not associated with the prevalence of hypoactive sexual desire disorder (HSDD) (Wierckx et al., 2014). However, quality of life was not
assessed within this study.

Given the literature’s confirmation that sexual orientation is not related with transition-related outcomes, it is necessary for medical professionals to ask for sexual orientation? Perhaps, in scenarios that are directly relevant; STD prevention, sex therapy, relationship counseling/therapy. But to the majority of the health professionals that trans individuals will encounter, it seems entirely unnecessary for them to ask and inquire as to the deeply personal nature of their sexual orientation.

Even more, this casts doubt on the diagnostic value of the purported ‘autogynephilia’. If we can classify ‘autogynephilic transsexuals’ and ‘homosexual transsexuals’ into two different categories, but the outcomes don’t differ, is there any value in differentiation?

Some Other Readings

A description of historical gatekeeping which importantly mentions the factor of sexual orientation

The Harry Benjamin Society standards

His book depicting the prototypical classification scale (page 19)

Experiences of gatekeeping in Thailand, Czech Republic, Germany

Assumptions about sexuality in the trans community

All of this goes to show the gatekeeping that arose from sexual orientation classification

Update – 11/16/18

Given that I choose a poor title for this piece, I’ll clarify what I had intended to communicate with the wording & the thought process I went through went writing & publishing this piece at midnight.

I was searching for more research for another piece when I came across the Chinese study (Yang et. al), recalled the existence of Nieder et. al (the literature review) and thought that the two could work together to make a coherent article on how it isn’t necessary for one’s medical professionals to inquire about sexual orientation (and thus the false ‘typology’) in order to impact decisions on providing treatment to patients. The articles linked in the Some Other Readings section articulate the issues with medical professionals asking about sexuality and using that to deny or delay treatment, which was is my primary criticism of the use of sexuality in medicine in trans-specific contexts (which is not to say that I oppose it). The existence of gatekeeping was intended to be a theme throughout the piece (and is something that I am eventually going to get around to writing on). Even more, the piece’s even larger overarching goal (as is the blog’s) is to criticize Blanchardianist ideology & criticize autogynephilia typology.

The “re”formulation of the title as “Or, does typology have any medical bearing on treatment?” helps contextualize the original purpose of the piece (as do the links to Kay Brown’s articles), but the chosen title then influenced the irrelevant and poorly worded content of the piece.

But the language I used obscured all of this; Medical professionals is far too broad of a term to refer to the individuals I intended to refer to: psychiatrists, psychologists and therapists – those who very often make diagnoses of trans individuals; the people who’ve been reported denying letters, recommendations and treatment because of sexual orientation; the paradigmatic gatekeepers. There are plenty of valid instances to ask for sexual orientation (although there may be more prudent and sensitive methods of obtaining the necessary information): for risk assessments for STD prevention, some therapeutic contexts, and so on as commenters on the Reddit thread insightfully pointed out. Even more, my crude estimation of the makeup of medical professionals trans people encounter could be false in many instances: it could be, for instance, that a trans individual is post-transition and encounters their primary physician far more than their psychiatrist (if they even have one).

A longwinded way of saying I’m sorry for choosing such a poor title.

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Editorial, TERFs

Daphna Joel and the Limits of Cis – Trans Dichotomies

Daphna Joel is one of my favorite researchers in the neuroscience field (along with Jordan-Young, Fine and a set of others – almost all of whom are implicitly supportive of trans people, the rest haven’t voiced any opinions or comment on trans people). But unknown to many is that she also does research specifically on trans and nonbinary individuals.

Queering Gender

The first paper she published in the field is Queering gender: studying gender identity in “normative” individuals. The paper develops a new “Multi-GIQ” scale for measuring gender identity in both trans and cis individuals. The scale is used in a sample of 2225 individuals contacted over the internet. Joel et. al plot the data on several charts with interesting visualization techniques, showing some interesting results. 2018-11-12 15_35_02-Sci-Hub _ Queering gender_ studying gender identity in ‘normative’ individuals _.png

Just by visual inspection we can note individuals that identify as men that feel more like men than women and vice versa. There is also some level of bigenderism among several individuals. We can easily point out that a cis-trans binary focused on identification as a gender not typically associated with the gender assigned at birth is incoherent because it obscures the reality of identification: many “cis” individuals would be classified as bigender under nearly all definitions of bigender, and many would be classified as agender. These gender identities are very commonly considered “trans”. Even more, there are several cis individuals who have feelings that contrast the gender they were assigned: a woman feeling much more like a man than a woman.

2018-11-12 15_50_00-Sci-Hub _ Queering gender_ studying gender identity in ‘normative_ individuals2

While ‘qu\r’ individuals obviously had the most non-normative identities, substantiative numbers of supposedly normative individuals wished to be that of the ‘opposite gender’. If we’re operationalizing gender dysphoria as such, which many people in the trans community do, then that begets the conclusion that cis people can be dysphoric (something I’m perfectly willing to accept despite odd pushback).

Taken together, our findings suggest that dichotomous gender categorisation does not reflect the complexity and multiplicity of gender experience. Rather, our study provides supportive evidence to non-binary theories of gender (e.g. Corbett, 2009; Dimen, 1995, 2003, 2005; Goldner, 1991, 2003; Harris, 1991, 2005) that perceive gender as fluid rather than dichotomous, and consider all human beings, not just gender nonconforming individuals, to have complex assemblages of gendered selves (Harris, 2005).

And

Specifically, 36.6% of our non-Queer subjects reported that they sometimes feel as the ‘other’ gender (of these, 24% received scores above 1), 63.7% reported that they sometimes wish to be the ‘other’ gender (of these, 34% received scores above 1), 49% did not always wear clothes ‘appropriate’ to their sex (of these, 26% received scores below 3) and 41.9% were sometimes discontent with their sexed body (of these, 52% received scores above 1). These findings suggest that except for discontent with one’s sexed body, which is by its very definition dysphoric, the other types of feelings should not be viewed as reflecting gender dysphoria but rather the complexity and multiplicity of ‘normal’ gender experience.

While I appreciate the concession that cis individuals can experience dysphoria via discontent with ones sexed body, the dismissal of alternative definitions of gender dysphoria is somewhat annoying: I’ve seen many individuals attempt to reconcile ‘all trans people have dysphoria’ with the acceptance of a variety of trans individuals by (re)defining dysphoria as the wish to become another gender. The research shows this method is untenable in maintaining a coherent cis-trans binary.

Thus, Coolidge et al. (2002) reported that 2.3% of children scored in the clinically significant range of a six-item DSM-IV-based GID scale. Other studies report cross-gender behaviour in 2.4–10.4% of boys and 3.3–22.5% of girls (van Beijsterveldt, Hudziak, & Boomsma, 2006; Zucker, Bradley, & Sanikhani, 1997), the wish to be the other sex in 1–13.3% of boys and 2.8–13.3% of girls (Wallien et al., 2009; Zucker et al., 1997) and feeling like the other sex or more like the other sex in 4.6–10.4% of children (Wallien et al., 2009). Lai et al. reported that 1.9% of adult males and 7.3% of adult females were gender dysphoric

Some interesting results from the literature (which confirm the results of the study) which seemingly contradict Kay Brown’s claims that gender dysphoria is more common in “male” individuals. I suspect that this is not a result of intrinsic prevalence of being trans among the populations, but rather a product of societal norms (my post about butches and ftms could be enlightening as to how identity can obscure prevalence as well as my unsupported estimate that more trans men live as butch women than trans women live as feminine men). Regardless, there needs to be a lot more research into prevalence of gender dysphoria and trans identity among various populations.

Our results also do not support the prevalent view in contemporary psychoanalytic and critical theories that individuals have a binary sense of gender and that the heterosexual– homosexual binary constitutes, stabilises and naturalises the male–female binary

And while I adore this study, Joel et. al completely misrepresent Butler’s point here. It’s to be expected given that Joel is a neuroscientist and Butler is a continental philosopher who uses some complicated language and terminology that requires copious amounts of references to comprehend completely. Correlates do not disprove Butler and co’s claims about how sexuality and gender are produced by society, the discourses that surround the identities and how closely the two are related. Even more, Sedgewick and Butler would very likely not say that individuals simply “have a binary sense of gender”, their claims have much more to do with the discourses that surround gender than introspection. Butler’s work almost specifically breaks down the idea that binary gender is universally present. Despite many ‘normative’ individuals having decidedly ‘non-normative’ identities, they continue to uphold a societal system of binarism documented time and time again. From a more logical standpoint, the binary between homosexuality and heterosexuality implicitly accepts the idea that there are two mutually exclusive and immutable genders that are universally present: homosexuality for same and heterosexual for different. Even more, Butler more specifically claims that the heterosexual matrix naturalizes the male-female binary through its application of heterosexuality to everyone until it is stated or shown otherwise. Despite my adoration for Joel, it seems she is out of her depth when she wades into the philosophical feminist literature attempting to disprove descriptive statements about culture and discourse using individual representations of internal gender identity.

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Jacobson and Joel recently published two studies relevant to our inquiry into the nature of gender identity. An Exploration of the Relations Between Self-Reported Gender Identity and Sexual Orientation in an Online Sample of Cisgender Individuals. and Self-Reported Gender Identity and Sexuality in an Online Sample of Cisgender, Transgender, and Gender-Diverse Individuals: An Exploratory Study.

The first notable thing that I want to highlight is not exactly related to gender identity or gender politics, but rather feminist politics and how MRAs (men’s rights activists) portray feminism politics. Table 2 indicates that 76.2% of women say they hold feminist views, 20.6% say ‘to some extent’ and only 3.2% do not. This is mirrored among men with moderately more negative reactions: 48.5% yes, 39.6% to some extent and 11.8% no. Contrary to the MRA narrative that ‘only 16% of women are feminists’, it seems as if a much larger portion are. Admittedly, this is not a representative sample and should not be extrapolated to the population as a whole, but it’s an interesting result that bears repeated testing with the same/similar questions.

As evident in Figs. 1, 2, 3, 4, and 5, many participants had what may be termed “queer” feelings, such as feeling both as a man and as a woman (38%) or as neither (35%), wishing to be the “other” gender (38%), or wishing to have the body of the “other” sex (35%)

A cross-cultural replication of the 2013 study, Joel again shows that a view that only trans people identify as genders other that they were assigned at birth is untenable and empirically false as a basis for cis-trans distinction.

The percent of binary individuals ranged between 8.8 and 40%, depending mostly on sexual orientation, with the highest percentage of binary individuals found in the exclusively heterosexual and exclusively homosexual groups, which did not signifcantly differ (p=.80), and lower percentage in the mostly heterosexual, bisexual, and mostly homosexual groups

The results also indicate that strict gender roles marginalize a majority of the population of cishet individuals. There may be correlations between identified gender and gendered performance, but that is definitively a product of social norms that are produced and reproduced by gendered performance and there exists a large population of individuals who defy these norms.

The present findings conflict with the common postulation of direct relations between biological sex, gender identity, and sexual orientation in two major aspects, which are clearly evident in Fig. 1. First, while scientific discourse usually perceives gender identity as a clear-cut, binary personality structure, our data reveal large variability in individuals’ gender identity with about a third feeling at least to some degree as the “other” gender. Second, and out of line with the idea that an “atypical” sexual orientation would entail an “atypical” gender identity, variability in gender identity was evident throughout the sexual attraction continuum, with an almost complete overlap between heterosexuals and non-heterosexuals in the range of scores on the different measures of gender identity. Moreover, even at the group level, only some non-heterosexual groups were significantly different from the exclusively heterosexual group. In fact, the finding that the group of exclusively homosexual men was not significantly different from the group of exclusively heterosexual men on any of the measures of gender identity is particularly in conflict with views strongly linking sexual orientation and gender identity. Our findings are in agreement, however, with the view that sexual orientation and gender identity are mostly distinct constructs.

Their summary of how the findings impact discourse on gender identity are good, but the bold part needs a large asterisk. The fact that sexual orientation and gender identity are coherently separate constructs is definitely a culturally specific phenomenon. In some cultures, gender and sexuality are not exactly considered distinct (see Thailand for example with gender identities and sexualities almost being considered identical in common parlance – which could have confounds when one looks at the Individualism vs Collectivism Hofstede scale and how it relates to the proportion of ‘nonhomosexual transsexuals’ in a country). In others, they’re interrelated in complex ways. Even more, the construct of sexuality is temporally and spatially-specific: cultures like that of the ancient Greeks and Romans viewed homosexuality not as a man loving another man, but a man being penetrated by a man – the act of penetration was not denigrated or deemed the same way as being penetrated was and moreover was not part of the same category. Foucault’s History of Sexuality is especially relevant on how sexuality and power are interconnected. And while gender identity and sexuality can be considered distinct constructs in the most abstract sense, we must also take note on how closely interrelated and intertwined one’s experiences of sexuality and gender identity fit together.

This finding is important because it highlights the fact that gender identities do not conform to narrowly defined dichotomous framings and suggests that identification with the “other” gender or wish to be the “other” gender or to have the body of the “other” sex are not necessarily a sign of gender dysphoria. Thus, our findings may normalize diversity in an area usually thought of as homogeneous, and by doing so help represent queer and transgender identities as belonging on the same gender grid as cisgender identities rather than as distinct phenomena.

One of my many gripes with the trans community (unfortunately transfeminists have many) is the insistence on telling individuals who have cross-gender feelings and urges that they must be trans in some fashion, that ‘only trans people want to be the “opposite” gender’, that ‘cis people don’t obsess over looking like the “opposite” gender’. It reifies an arbitrary distinction between cis and trans and while self-validating and potentially externally affirming, problematically erases the experiences of cis individuals who do in fact experience the feelings that many claim they don’t. Here it is in writing, wanting to be the “opposite” gender/sex cannot be the operationalization of gender dysphoria. Gender dysphoria contemporarily can be considered a polysemic construct rather than a homogeneous term, perhaps best represented by a Wittgensteinian family resemblance (see my article on ftms and butches on family resemblances and how they relate to gender).

More generally, our study adds to a growing body of literature that challenges dichotomous conventions within the science of gender and sexuality (for a recent review, see Hyde, Bigler, Joel, Tate, & van Anders, in press).

Most excitingly for me is my discovery that Joel is writing a new paper that reviews the research on gender and sexuality.

2018-11-13 12_23_16-Sci-Hub _ An Exploration of the Relations Between Self-Reported Gender Identity

We can note that among many sexuality subgroups, men have higher scores on the ‘wish to be the “other” gender” item, and that both items varies non-monotonically with sexuality.

22

Again visual inspection yields individuals that dislike their sexed body and want to have the body of the “other” sex. Furthermore, the individuals are notably not exclusively homosexual.

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The graph from the discussion on gender roles above.

There are numerous other little important results that if I were to include and discuss them would make this post much longer than would make it useful or readable.

Gender Diverse

Jacobson and Joel released another 2018 study, Self-Reported Gender Identity and Sexuality in an Online Sample of Cisgender, Transgender, and Gender-Diverse Individuals: An Exploratory Study. It used a European-American sample of individuals rather than the original Israeli sample of the pioneering study, compromising a cross-cultural replication. It also introduces terminology not used in the pioneering study; “gender diverse”. I appreciate the movement away from ‘qu\r’ and while I think it’s the best solution, more could be done to clarify that genderqueer/nonbinary people can be transgender.

112

Again, there are AMAB men that feel like women and AFAB women that feel like men, cis men/women who feel like men and women, and cis men/women who feel somewhat unlike men and women. Also of note is that trans women/men feel less like women/men and more like men/women than cis women/men, again rebutting the idea that only trans people ‘feel’ like their gender.

115

Again, we note large numbers of cis individuals that feel like neither gender or as both genders, as well as trans individuals having higher rates of this (we see all of these values are quantifiable and almost all are significant in Table 2).

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While we can easily note that trans and gender diverse individuals have much higher nonbinary scores on average, the range of these scores is almost identical among the 6 groups. This precludes the idea that nonbinary scores can, in every case, discriminate trans/nonbinary individuals from cis people (without forcefully categorizing individuals to best fit preconceived notions of the categories that best fit ones’ ideology).

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And yet again, cis women and cis men have higher feelings of validity about their actual gender, unsurprisingly. Unfortunately this was not broken down by sexual orientation, but it’d definitely be a great exercise to see how homophobia/lesbophobia/biphobia/etc affects conceptualization of one’s gender identity as valid or invalid.

Implications for Trans Discourse

TERF Discourse

Joel et. al 2013

  • While the studies may be dismissed on face value by TERFs for using terms like ‘gender identity’ (of which I’m personally skeptical of, but that’s aside from the point) and directly referencing trans people in a supportive manner, Joel is famed in the radical feminist community because her researchers has important implications in the field of neuroscience of sex differences, namely that there are no “male” or “female” brains. In response to any claims about trans brains, they’ll typically cite Joel’s 2015 PNAS study while ignoring the nuances of the ‘trans brain studies’ (which they tend to homogenize into a monolith) that don’t necessarily claim that ‘male’ and ‘female’ brains exist. Many are reliant upon specific non-sexually dimorphic regions of the brain where trans individuals show atypical areas, values or signals, or make claims about the similarity of trans brains to cis brains that doesn’t create constructs of male/female brains. The long story short is that she’s widely cited in TERF spaces and has some level of credibility among them.
  • A common TERF claim is that “women don’t have gender identity” or “only trans people have gender identity”, both claims that are ‘disproven’ by the study. Gender identity was found to be persistent throughout large portions of the cis population, and many individuals reported ‘feeling like a woman’ / ‘feeling like a man’, things TERFs claim that do not exist in women (despite trans people pointing out that they often don’t understand the concept and/or don’t relate to it). [I’m separately skeptical about claims of feeling like a man/woman]
  • Another TERF claim about gender identity is that women have non-normative gender identities because societal misogyny disassociates them from their femaleness (the latter clause likely being true). But the study indicated that men have slightly higher non-normative gender identification, making it dubious to claim that misogyny is the cause of non-normative gender identity.
  • Yet another claim is that linking gender identity to sexual orientation, which is a claim that the study tested and disproved. There was no significant (non-scientific meaning) association with non-normative gender identity. Overall, r values were low. Even more, sexual orientation was not related with discontent with one’s sexed body; lesbians were not more likely to hate their body that heterosexual women.
  • Figure 7 indicates that qu\\rs have higher values of discontent with ones body, indicating that assertions that ‘all women are unhappy with their body’ are misleading and ignore the extent that trans individuals are unhappy/dysphoric about their body.
  • Gender roles aren’t upheld by trans/qu\\r individuals: “Men were more compliant with dress code than Women, and both Men and Women were more compliant than Queers”

Jacobson & Joel 2018

  • The research further confirms the results laid out above: that cis people have gender identities and “feel” like men/women, that sexual orientation and gender identity are very weakly linked (and not in a monotonic manner)
  • The second 2018 study we analyzed indicates that cis women and cis men have very similar feelings of non-normative gender identity. Even more, trans men/women and gender diverse individuals have much higher rates of feeling like neither gender or both genders than cis people do. It also confirmed results from previous studies about the interaction between sexuality and gender identity.
  • Essentially everything found in the Israeli sample was replicated in the predominantly English-speaking sample, lending further validity to the results.

Some Other Readings

A few of these were from the studies themselves, but I think should be highlighted for their specificity of the topic

Martin et. al 2016 A Duel Identity Approach for Conceptualizing and Measuring Children’s Gender Identity (Warning for binarism)

Nicole Rea’s Blurred Lines*: A Critical Examination of the Trans/Cis Dichotomy

Julia Serano (who I’m somewhat critical of) has a great essay describing the complexities of cis terminology

And a Tumblr post that articulates more specific problematic results of the cis-trans dichotomy rather than my accuracy-based analysis

Intersex-specific issues with the cis-trans dichotomy can be explored here and here, with personal experiences relayed here and here

Survey results highlighting the issue of casting the cis-trans binary onto nonbinary people

sillyolme

Cherrypicking The Transgender Brain

(Post in question)

I won’t comment on the Daphna et. al literature, because it’s still an emerging line of research that has some more philosophical and definitional questions as to what actually constitutes dimorphism (I’ve seen contradicting meanings).

Ummm… this result is in complete agreement with another hypothesis that many transwomen find uncomfortable, one made by Ray Blanchard, in which he hypothesized that late transitioning transwomen would have brain structure differences from both men and women that would NOT be sexually dimorphic; while young (“homosexual”) transsexuals would show shifts in sexually dimorphic structures toward female morphologies.  There was an earlier review of previous studies (which I also wrote a post about) that had shown that hypothesis to be supported.

There’s also recent research that shows controlling for sexuality has absolutely no effect on trans brain structures.

From the abstract:

However, controlling for individual estradiol, testosterone, or progesterone plasma levels or for subjects’ sexual orientation did not change group differences

And then in the statistical analyses section they explain their control:

To investigate whether the three sex steroid hormones (E2, T, and P4) or sexual orientation explained group differences, the named variables were added as covariates of no interest within separate ANCOVA analyses. Finally, multiple regression analyses were performed to determine the effects of hormones and sexual orientation on diffusivity maps independent of group membership, i.e., with group in addition to TIV as factor of no interest. Separate models were calculated for each of the independent variables (E2, T, P4, and sexual orientation). Because hormone values over the entire sample were non-normally distributed, they were transformed to ordinal scales based on ranks before inclusion in the analysis. Sexual orientation was entered into analyses in three different ways of coding: (1) as raw values of the Likert scale (1 for attraction toward females; 7 for attraction toward males); (2) as a spectrum from homosexuality (e.g., 1) to heterosexuality (e.g., 7) with reference to the raters’ genetic sex; and (3) as a spectrum from homosexuality to heterosexuality with reference to the raters’ gender identity. The statistical threshold was set at p < 0.05 FWE corrected, using the threshold-free cluster enhancement method to define the clusters (). Voxels showing significant differences were assigned to white matter tracts using the DTI-81 white matter atlas of the International Consortium for Human Brain Mapping as provided by the DiffeoMap software package (www.mristudio.org/wiki/user_manual/diffeomap). Diffusivities based on tract-specific quantification for right and left CST, Fmajor, and Fminor were compared using ANOVA in SPSS. Separate models were calculated for each tract and diffusivity parameter, followed by post hoc pairwise comparisons and correction for multiple comparisons using the Bonferroni’s procedure. Analyses were run with and without TIV as covariate of no interest. Separate correlation analyses were performed to examine the association between diffusivities and age and between volumetric data [gray matter volume (GMV), white matter volume (WMV), CSF, and TIV] and age for each group.

And their results:

Here, we investigated whether sexual orientation associates with diffusivity measures. No effects on our main findings were observed when sexual orientation was regressed out in the ANCOVA design. Moreover, there was no significant effect of sexual orientation on diffusivity parameters in the regression analysis including all subjects and using group as factor of no interest.

And furthermore:
In our study, we find robust differences between investigated groups in MD, AD, and RD indicating that biological sex and gender identity both contribute to observed group differences. Moreover, the high positive correlation with adult plasma T levels (controlling for group membership) indicates that group differences cannot be explained by peripheral sex hormone plasma levels. As expected, biological males (MCs and MtF transsexuals) had higher T levels than biological females (FCs and FtM transsexuals), whereas group differences in diffusivity values showed the transition FC > FtM > MtF > MC. Furthermore, group differences were not explained by differences in sexual orientation, narrowing potential determinants for differences in diffusivity parameters to biological sex and gender identity.
As I said, I don’t particularly care about etiological debates over neurology considering the field is new enough to warrant skepticism about replicability and usefulessness, and the extent that socialization and environmental factors affect brain neurology.
But I’ll offer an alternative interpretation of the data that lesbian trans women have ‘masculinized brains’ (taking that as an axiom for the purpose of argument).
We know from some recent on the neurology of gay men and lesbian women that sexual orientation has an effect on brain neurology independent on trans status:

diffusivities and age and between volumetric data [gray matter volume (GMV), white matter volume (WMV), CSF, and TIV] and age for each group.

A 2008 study demonstrating that homosexual men and women have sex-atypical brain structures

The connectivity pattern in homosexual subjects was almost reciprocal in relation to the same-sex controls

Second, HoM, just as HeW, displayed connections with the contralateral amygdala, the anterior cingulate, the subcallosum, and the hypothalamus

Group comparisons confirmed these findings: HeW, as well as HoM, showed a greater connectivity with the contralateral amygdala and the cingulate cortex compared with both HeM and HoW.

We also found that the hemispheric ratios, as well as the patterns of amygdala connectivity, were sex atypical in homosexual subjects, with HoM exhibiting more female patterns and HoW showing more male-like features (albeit less pronounced).

(Note that this has been replicated quite a few times)

A TERF or transphobe could easily interpret this data to show that “trans women are just gay men!” and “trans men are just lesbian women”, which is exactly why the neurological argument is intrinsically flawed. But this data yields an alternative interpretation of the (contested) result that lesbian trans women have brains more similar to that of men: they should. Just like lesbian cis women have brains “more similar to that of heterosexual men” (to paraphrase), lesbian trans women do too. My conclusion is that brain structures are not organized by sex or gender, but by who one is sexually attracted to. Male/men-attracted people and female/woman-attracted people differentiate themselves. It’s internally consistent with the data, while the “male brain” / “female brain” hypothesis is not: gay men and lesbian women provide contradicting data. The issue is not one of data, but one of the paradigms we interpret the data through.

Now, this is all moot if we take the data from the study that I cited above that showed that sexual orientation had no impact on brain structures for trans individuals, which just explicates that trans brains are neurologically distinct than cis brains categorically rather than by subgroups

But either way we look at it, her argument is incorrect in some manner: paradigmatically or scientifically.

Searcy is likely to have written her article in an attempt to discount the growing evidence from transgender brain scan research that shows that the two type taxonomy for transwomen is supported.

There’s exactly one study that has shown gynephilic trans women have ‘male brains’, and there is at least one that shows the contrary. I wouldn’t be so eager to run and shout that the two type taxonomy is supported by the research

Where once older transitioning transwomen cherry picked the brain structure research in an attempt to spin it such that all transwomen had female brains.  She is spinning the science to lead us to believe that brain structure research is unimportant and should be ignored, first by saying that there is no brain structure sexual dimorphism of any consequence and then say that what differences between transgender folk and nontransfolk is unimportant anyway.

This just gets back into the debate over dimorphism, which as I said I won’t get into those weeds today, but I’d just emphasize that it’s not a simple topic. There are fundamental philosophical disagreements over what constitutes sexual dimorphism between the two camps that can’t be ignored by saying that ‘one side is supported by the evidence’ and that the other isn’t.

I believe it represents a growing fear by autogynephilic transwomen that the brain scan science will undermine their own identity as transwomen if the public were to become aware of what the evidence means.

To me it seems Brown is alluding to her own denial of lesbian trans women’s identities and womanhood, which contradicts her stated “support” of “autogynephilic transwomen”