If you ask most experts in the field what causes someone to become transgender (as in experiencing gender dysphoria or being gender incongruent), they will tell you that this most likely caused by a combination of biological, cultural, social and personal factors. Most of them will agree that there is a significant biological component.
This is important, because it means that it is hard to dismiss gender incongruence as something imaginary caused by political and cultural pressure from sinister people promoting some kind of "gender ideology". All serious scientists in the field acknowledge that the identities of trans people are real and tangible and the great majority believe there are biological factors influencing the development of gender incongruence.
That does not mean that our concepts of gender are not influenced by culture. They most certainly are, as seen in the anti-trans insistence on gender being reduced to "biological sex", another concept that is as vague and ambiguous as the term "gender".
"Biological sex", as it is used by anti-trans activist, is a political and cultural construct that goes against everything we know about gender variance and intersex conditions, both in humans and in other animals.
In intersex people chromosomes, gonads, genitalia and hormones do not match in wide variety of combinations, and in trans people a persistent and intense experience of a gendered self does not mach the gender assigned at birth. Dismissing this as "illusions" or "irrelevant variations" does not cut it.
What science says about the biological component
Research indicates significant biological factors influencing gender identity and dysphoria, particularly in brain structure and function.
Neuroimaging studies reveal sex-atypical brain features in transgender individuals, aligning more closely with their experienced gender than their assigned sex.
Genetic studies suggest a polygenic component (involving many genes) to gender dysphoria, with higher concordance rates in monozygotic twins compared to dizygotic twins, indicating heritable influences. (Monozygotic twins are twins that develop from one single fertilized egg that splits into two embryos early in pregnancy.)
The prenatal endocrine environment refers to the hormonal conditions in the womb during pregnancy that influence the development of the fetus. Prenatal hormone exposure plays a crucial role in brain sexual differentiation. Conditions with atypical androgen signaling show increased rates of gender dysphoria, suggesting that the prenatal endocrine environment significantly impacts gender identity development.
Current research provides evidence that gender identity and gender dysphoria are strongly influenced by biological factors, especially brain sexual differentiation and genetics, within a complex mind/body/society framework.
Relevant literature
Saksham, S., Deeksha, S., Udithi, B., & Vinayaka, G. (2023). The neurobiology and neurocognition of gender dysphoria. InterConf. https://doi.org/10.51582/interconf.19-20.12.2023.026
Nowak, K., Stępień, P., Marczak, A., Halczuk, I., Stachura, B., Górska, J., Gawryszczak, S., Gliwa, A., & Halczuk, I.(2024). Gender dysphoria and incongruence - neurophysiological diversity and genetic factors. Current Problems of Psychiatry. https://doi.org/10.12923/2353-8627/2024-0023
Boucher, F., & Chinnah, T. (2020). Gender Dysphoria: A Review Investigating the Relationship Between Genetic Influences and Brain Development. Adolescent Health, Medicine and Therapeutics, 11, 89 - 99. https://doi.org/10.2147/ahmt.s259168
Altinay, M., & Anand, A. (2019). Neuroimaging gender dysphoria: a novel psychobiological model. Brain Imaging and Behavior, 14, 1281 - 1297. https://doi.org/10.1007/s11682-019-00121-8
Ettner, R. (2020). Etiology of Gender Dysphoria. Gender Confirmation Surgery https://doi.org/10.1007/978-3-030-29093-1_2
Sari̇, M., Savci, U., Balta, B., Öztürk, Y., & Tufan, A. (2023). Neurobiological Components of Sexual Identity Development and Epigenetic Effects of Environmental Stressors - Current Approaches in Psychiatry.https://doi.org/10.18863/pgy.1238867
Duisin, D., Barišić, J., Milovanović, S., Bizic, M., & Đorđević, L. (2018). Neurobiological basis of gender dysphoria -actual hypothetical models, 40, 54-72. https://doi.org/10.5937/engrami1802054d
Stevenson, D., Murray, J., Muglia, L., Wong, R., & Katz, M. (2023). Challenges to the study of gender dysphoria.Acta Paediatrica, 112, 2273 - 2275. https://doi.org/10.1111/apa.16975
Fernández, R., Ramírez, K., Lorente-Bermúdez, R., Gómez-Gil, E., Mora, M., Guillamón, A., & Pásaro, E. (2024).Analysis of single nucleotide polymorphisms of the metabotropic glutamate receptors in a transgender population.Frontiers in Endocrinology, 15. https://doi.org/10.3389/fendo.2024.1382861
Mueller, S., De Cuypere, G., & T Sjoen, G. (2017). Transgender Research in the 21st Century: A Selective CriticalReview From a Neurocognitive Perspective.. The American journal of psychiatry, 174 12, 1155-1162.https://doi.org/10.1176/appi.ajp.2017.17060626
Saraswat, A., Weinand, J., & Safer, J. (2015). Evidence supporting the biologic nature of gender identity. Endocrinepractice : Official journal of the American College of Endocrinology and the American Association of ClinicalEndocrinologists, 21 2, 199-204. https://doi.org/10.4158/ep14351.ra
Swaab, D., Wolff, S., & Bao, A. (2021). Sexual differentiation of the human hypothalamus: Relationship to genderidentity and sexual orientation. Handbook of clinical neurology, 181, 427-443. https://doi.org/10.1016/b978-0-12-820683-6.00031-2
Saleem, F., & Rizvi, S. (2017). Transgender Associations and Possible Etiology: A Literature Review. Cureus, 9.https://doi.org/10.7759/cureus.1984
Kauffman, R., Guerra, C., Thompson, C., & Stark, A. (2022). Concordance for Gender Dysphoria in Genetic FemaleMonozygotic (Identical) Triplets. Archives of Sexual Behavior, 51, 3647 - 3651. https://doi.org/10.1007/s10508-022-02409-1
Fernández, R., Guillamón, A., Cortés-Cortés, J., Gómez-Gil, E., Jácome, A., Esteva, I., Almaraz, M., Mora, M.,Aranda, G., & Pásaro, E. (2018). Molecular basis of Gender Dysphoria: androgen and estrogen receptor interaction.Psychoneuroendocrinology, 98, 161-167. https://doi.org/10.1016/j.psyneuen.2018.07.032
Saffie, J., & Bäuerle, N. (2023). Etiology of gender incongruence and its levels of evidence: A scoping review protocol. PLOS ONE, 18. https://doi.org/10.1371/journal.pone.0283011
Thanks to Davida for putting up the list of sources.
Illustration: Getty
Jack, thank you (and Davida) for this article.
ReplyDeleteI spent all of 2015 reading everything (academic articles, books) I could find and speaking with professionals with a single aim: to determine for myself whether or not gender dysphoria has a biological basis. Although by that time I had over a half century of personally experiencing it, I wanted to be sure. If not, I felt, there ought to be a way (through therapy, most likely) to help me with my pervasive feelings. I came away convinced that although at least at that time, there was an imprecise understanding, that gender dysphoria has its roots in the brain.
Regarding cultural and sociological factors: of course they also have influence. As a transgender woman born raised on the West Coast of the US, I naturally prefer my expressions of identity much differently than, say, women in the Middle East.
The proof is in the pudding as they say. I transitioned nine years ago and am pleased to report much greater comfort in my skin and no regrets.