Bored? In a hurry? Short attention span? Here are brief answers to some of the most frequently asked questions about transsexual athletes.
I have, like, 60 seconds. Summarize your argument for allowing transsexual women to compete in women's divisions.
After surgery and a few years of hormone therapy, transsexual women are physiologically female. The advantages yielded by high levels of testosterone are reversed, and transsexual women usually have lower testosterone than non-transsexual women because their body does not contain any structure that produces a lot of testosterone. The Y chromosome performs no function that does not get "overwritten" by the removal of the testes and estrogen replacement therapy. Any other physical variation (body composition, skeleton shape, etc.) accumulated by puberty falls within the standard variation in the female gender. For sports where body types offer an advantage, they are already divided to accommodate that (usually by weight class).
For these reasons, almost every international sports governing body has already adopted a trans inclusion policy that requires the removal of gonads and a couple of years of hormone therapy. After that, transsexual women compete safely and fairly with other women.
Didn't the IOC make their policy for reasons of political correctness? There are no studies confirming the safety of transsexual women competing with non-transsexual women.
The IOC policy was created by a group of seven physicians and researchers with expertise in relevant fields, not laypeople. They understand the physiological differences caused by changes in hormone levels, and how those changes affect the body. They also understand what constitutes a physiological advantage in sport. The changes undergone by transsexual women after hormone therapy are well understood and well researched. They don't need studies to specifically test safety because the primary physiological advantage--high levels of testosterone--has been eliminated.
What causes transsexuality? Is it a choice?
This is an edited version of a forum post by Sherdog user "100% Jiu-Jitsu". Gender identity is more complicated than a simple male/female distinction, but there is strong evidence that there is a neurological basis for the gender identity inconsistency that transsexuals experience.
As a man, if a wizard cast a spell on me so tomorrow morning I looked in the mirror and saw a female body, then I still wouldn't consider myself a woman. Every guy that I've talked to has told me that he would feel that he was still a man... just one trapped in a woman's body.
That simple mental experiment illustrates the difference between one's biological sex and one's gender identity. The hypothetical scenario relied on magic to create a difference between one's genitals and one's gender identity. In real life, the process can occur in utero. "As the sexual differentiation of the genitals takes places much earlier on in development (in the first 2 months of pregnancy) than the sexual differentiation of the brain (starting in the second semester of pregnancy and becoming overt upon reaching adulthood), these two processes may be influenced independently of each other, which may result in people with male sexual organs who feel female and vice versa (a phenomenon called transsexuality)." (Swaab DF. Sexual differentiation of the brain and behavior. Best Pract Res Clin Endocrinol Metab 2007;21:431-44.)
The theory that transgenderism originates from altered prenatal sex hormones is supported by a substantial and growing body of evidence. The parents of MTF individuals "report that, from the moment their sons learned to talk, they insisted on wearing their mother's clothes and shoes, only showed an interest in girls' toys, and mostly played with girls." (Swaab, 2007.) "There are no indications that postnatal social factors could be responsible for the occurrence of transsexuality." (Swaab, 2007)
The prenatal-hormone theory accounts for the unusually high percentage of transpeople who are left handed when compared to the rest of the population. (Swaab, D. F. (2004). Sexual differentiation of the human brain: relevance for gender identity, transsexualism and sexual orientation. Gynecological Endocrinology, 19(6), 301-312.) It also accords with research on congenital hyperplasia, which shows that female fetuses are between 300 and 1,000 times more likely to be transgendered if they are exposed to extreme levels of testosterone in utero. (Zucker KJ, Bradley SJ, Oliver G et al. Psychosexual development of women with congenital adrenal hyperplasia. Hormones and Behavior 1996; 30: 300–318.) The opposite phenomenon appears among males whose mothers took the synthetic estrogen DES while pregnant; the organization representing these men reports that 35% of its members are transgendered! (Swaab, 2007)
But that is not even the sockdolager! The most powerful proof of transgenderism comes from neuroscience, where researchers have identified sex-dimorphic features in the brain. In other words, there are certain structures in the brain that develop one way in men and another way in women. Researchers have repeatedly found that these features are REVERSED in the brains of trans people!
Here are the studies I'm aware of:
"In summary, our observations suggest that the small size of the BSTc in male-to-female transsexuals cannot be explained by differences in adult sex hormone levels, but is established during development by an organizing action of sex hormones." (J. N. Zhou, M. A. Hofman, L. J. Gooren and D. F. Swaab, "A Sex Difference in the Human Brain and Its Relation to Transsexuality," Nature, Vol. 378, No. 6552, 1995, pp. 68-70.)
"The present findings of somatostatin neuronal sex differences in the BSTc and its sex reversal in the transsexual brain clearly support the paradigm that in transsexuals sexual differentiation of the brain and genitals may go into opposite directions and point to a neurobiological basis of gender identity disorder." (Kruijver FP, Zhou J, Pool C, Hofman MA, Gooren LJ, Swaab DF. Male-to-female transsexuals have female neuron numbers in a limbic nucleus. J Clin Endocrinol Metab 2000;85:2034–41.)
"The data show that there is indeed a sex difference in the INAH3 subnucleus that is reversed in transsexual people and is only partially influenced by alterations in sex hormone levels in adulthood." (A. Garcia-Falgueras and D. F. Swaab, "A Sex Difference in the Hypothalamic Uncinate Nucleus: Relationship to Gender Identity," Brain, Vol. 131, No. 12, 2008, pp. 3132- 3146.)
"In conclusion, our results show that the white matter micro-structure pattern in untreated FtM transsexuals is closer to the pattern of subjects who share their gender identity(males) than to those who share their biological sex (females).Our results provide evidence for structural differences in the untreated FtM trans-sexual's brain." (G. Rametti, B. Carrillo, E. Gómez-Gil, C. Junque, S. Se-govia, A. Gomez, et al., "White Matter Microstructure in Female to Male Transsexuals before Cross-Sex Hormonal Treatment. A Diffusion Tensor Imaging Study," Journal of Psychiatric Research, Vol. 45, No. 3, 2011, pp. 199- 204.)
"These findings provide further evidence that brain anatomy is associated with gender identity, where measures in MTF transsexuals appear to be shifted away from gender-congruent men." (Luders, E., Sánchez, F. J., Tosun, D., Shattuck, D. W., Gaser, C., Vilain, E., & Toga, A. W. (2012). Increased Cortical Thickness in Male-to-Female Transsexualism. Journal of Behavioral and Brain Science, 2, 357-362.)
Aren't transsexual women just men who cut their penises off?
No. Transsexual women usually (but not always) have a Y chromosome. Their gender identity and gender presentation are female. Transsexual women have a few options for surgery, some of which are very limited based on their health care coverage. Many of them undergo removal of their testes. Some of them have a surgery that creates female genitalia. Almost all of them undergo extensive hormone therapy to suppress testosterone (an androgen) and other male hormones, and to increase their level of estradiol (an estrogen). Physiologically, this makes their bodies operate the same as non-transsexual women who have had their ovaries removed.
What should I call a transsexual woman? He? She? It?
A transsexual woman should be referred to as "she" or "her", just like any other woman.
Don't most organizations ban transsexual women from competing with other women?
The IOC, FILA, the NCAA, the Association of Boxing Commissions, the LPGA, and several state and provincial athletic organizations have trans inclusion policies, including in contact/combat sports like hockey, MMA, boxing, wrestling, and judo. This is because the organizations recognize that transsexual women have bodies that are physiologically female. Usually, for trans women, the policy requires that they have genital surgery that removes their testes, and undergo estrogen therapy for a minimum of two years after surgery. This gives the body time to eliminate the significant advantages that the presence of testosterone offers. Testosterone is a performance-enhancing substance. Estrogens are not.
Doesn't the skeleton of a transsexual woman give her physical advantages over a non-transsexual woman?
There is tremendous variation within a gender's skeletal dimensions, and even trained forensic experts can only identify the gender of a skeleton from its bones 9 times out of 10.
It is not clear how bone density improves performance in most sports. XY people generally have a higher bone mineral density than XX people after going through puberty. However, estrogens also preserves bone density, which is why post-menopausal women take estradiol to help prevent arthritis. And athletes who do any resistance training (load-bearing movements like weightlifting) of both genders have excellent bone density.
Without testosterone, bone density will decrease after several years, giving transsexual women a similar bone density to non-transsexual women who have similar resistance training experience. But again, there is no research showing that a higher bone density improves sport performance unless you are comparing to a person with an osteoporotic skeleton... in which case the person with osteoporosis should be doing weight training and maybe taking estrogen to retain their bone density.