43 - Debunking Brain Studies - Part II

In the first part of this series, we learned how the claim that one can be “born with a female brain in a male body” or vice versa does not hold up when reading scientific studies. When comparing those who identify as trans and those who do not, the only significant difference was in regions related to self-perception of one’s body. This makes sense, as many who believe they are trans become hyper-fixated on one or more body parts. When you use a certain part of your brain more than others, the neuronal connections in that area grow. (As we’ll see later in this post.)

Reviewing the Assertion

The other differences in brain scans among those who identify as trans coincided with their self-reports of homosexuality (measured in a variety of ways). Below, we can see the assertion that one is “truly” gay or lesbian:

Why does this matter? Because most people who identify as transgender are not exclusively heterosexual, and same-sex attraction has been linked to neuroanatomical differences that reflect a cross-sex shift—or, more broadly, to a reduction in typical sexual dimorphism (i.e., to having more androgynous brain structures). This raises serious methodological concerns about the extent to which sexual orientation might confound or interact with the neurobiological markers that “brain sex” studies routinely attribute to gender dysphoria. It also raises major ethical concerns about the use of “gender-affirming care” as a form of gay conversion therapy or as a maladaptive coping strategy for gay men.[1]

Homosexual orientation was found to be associated with less pronounced cerebral sex dimorphism, a finding that appeared more prominent among men than women. Although a less pronounced cerebral sex dimorphism was detected in transgender persons compared with heterosexual cisgender controls, this seems primarily due to the higher proportion of homosexual persons in the GD [Gender Dysphoric] groups, and does not seem to be the signature of GD. We suggest that GD is, instead, specifically linked to cerebral networks mediating self–body perception, possibly due to certain developmental and acquired changes.[2]

Confusion or insecurity about one’s gender may be “due to certain developmental and acquired changes,” but sexual orientation is not questioned. Homosexual orientation is presented as a given, with brains that appear more androgynous attributed to homosexuality. While it is good to avoid medicalizing individuals who would be better served by addressing the underlying concerns that led them to believe they were trans, it is not good to presume that homosexual behavior, desires, and/or identity is or will be a permanent part of one’s life. Adopting either identity can be seen as a maladaptive coping strategy.

Behavior Impacts Biology

The foundational principle of brain plasticity applies in all cases. Dr. Neil Whitehead (PhD in Biochemistry) [3] wrote of the impact our behavior and focus has on the brain:

Violinists have a grossly enlarged area of the brain devoted to the fingers of their left hands. Those who learn a juggling routine for three months produce observable small changes in the small-scale structure of the brain, and these changes reverse when they stop. 20

London taxi drivers have an enlarged area of the brain dealing with navigation. Is this innate? No. London bus drivers on set routes did not have this enlarged area, and on retirement of the taxi drivers, the brain area involved diminished.25 Taxi drivers were not born that way, but developed the brain area through huge amounts of navigation and learning, and only maintained it through constant use.[4]

[Note: Before GPS, taxi drivers in London had to memorize a massive array of streets and addresses.]

Psychiatrist and psychoanalyst, Dr Norman Doidge wrote The Brain That Changes Itself: Stories Of Personal Triumph From The Frontiers Of Brain Science, which overturned the notion that the brain is a fixed entity. This is taken from an interview of Dr. Doidge with host Allan Gregg[5]:

Well plastic means plastic in the sense of plasticine – modifiable, adaptable. The plastic brain is a brain that can change its structure and its function depending on…what you do with your brain. The task at hand that you are working on, what you're perceiving can cause you to change the structure of your brain on many levels. …what you think and imagine actually can change the structure of your brain down to the very connections between the brain cells down into the genes even.

…One of the most staggeringly interesting discoveries of the late 20th century was the discovery that learning changes the number of connections between the neurons - the nerve cells. In a nervous system, you can go, for instance, from having perhaps 1300 connections between nerve cell A and nerve cell B to 2700 with several hours of training.

…What happens is thoughts or activities that you do with your brain actually turn certain genes on and others off inside the nerve cells, which then make proteins, which then change the structure.

…Since the rise of modern science, most educated people see human nature in some way as emerging from the human brain, and if the human brain was [a] fixed, immutable, and a rigid structure, it made a lot of sense to think of human nature as fundamentally fixed. And so we have to reexamine all that, and I begin to do that in this book.

In their meta-analysis, “Sexuality and Gender: Findings from the Biological, Psychological, and Social Sciences,” Dr. Lawrence S. Mayer and Dr. Paul R. McHugh wrote about the confusion between cause and effect in looking at brain studies:

…Another study showed differences in cerebral asymmetry and functional connectivity between homosexual and heterosexual subjects.[98]

While findings of this kind may suggest avenues for future investigation, they do not move us much closer to an understanding of the biological or environmental determinants of sexual attractions, interests, preferences, or behaviors. We will say more about this below. For now, we will briefly illustrate a few of the inherent limitations in this area of research with the following hypothetical example. Suppose we were to study the brains of yoga teachers and compare them to the brains of bodybuilders. If we search long enough, we will eventually find statistically significant differences in some area of brain morphology or brain function between these two groups. But this would not imply that such differences determined the different life trajectories of the yoga teacher and the bodybuilder. The brain differences could have been the result, rather than the cause, of distinctive patterns of behavior or interests.[99] Consider another example. Suppose that gay men tend to have less body fat than straight men (as indicated by lower average scores on body mass indices). Even though body mass is, in part, determined by genetics, we could not claim based on this finding that there is some innate, genetic cause of both body mass and homosexuality at work. It could be the case, for instance, that being gay is associated with a diet that lowers body mass. These examples illustrate one of the common problems encountered in the popular interpretation of such research: the suggestion that the neurobiological pattern determines a particular behavioral expression.[6]

Studies of the brains of homosexuals and heterosexuals have found some differences, but have not demonstrated that these differences are inborn rather than the result of environmental factors that influenced both psychological and neurobiological traits.[7]

So, in all cases – those who identify as trans and those who have experienced attractions to the same sex, we need to keep in mind that the brain is not hardwired. Just as taxi drivers were not born with a larger internal navigation system, we cannot conclude that anyone was born with a brain bent towards attractions to the same sex. In the next edition of R4R, we’ll explore how the brain’s ability to change can be applied in ministry.

[1] https://www.city-journal.org/article/transgender-brain-sex-studies-flawed

[2] A Manzouri, I Savic, Possible Neurobiological Underpinnings of Homosexuality and Gender Dysphoria, Cerebral Cortex, Volume 29, Issue 5, May 2019, Pages 2084–2101, https://doi.org/10.1093/cercor/bhy090

[3] Neil Whitehead: PhD in biochemistry, 1971, New Zealand, employed as a scientist with the NZ Govt (24 years), the United Nations (4 years), and more recently as a scientific research consultant. Dr. Whitehead is the author of the book My Genes Made Me Do It - Homosexuality and the scientific evidence, and over 150 published scientific papers. https://mygenes.co.nz/about_us.html

[4] “Brain Plasticity Backs up Orientation Change,” N.E.Whitehead, Ph.D (For a fuller treatment of this subject see Chapter Eight, My Genes Made Me Do it!)

[5] Norman Doidge & Allan Gregg: The Brain That Changes Itself, quote begins at approx. 1:15

[6] “Sexuality and Gender: Findings from the Biological, Psychological, and Social Sciences,” Dr. Paul McHugh and Lawrence S. Mayer, M.B., M.S., Ph.D., pg 40-41

[7] Ibid