Long ago, before there was Humankind and their rules, there was Nature. Nature was the most imaginative of energies, for it would bring to life, species that even our brains could not fathom. In its world, every energy was Normal, each of them fluctuating with their own ebbs and flows. To constrict their tides was equivalent to declaring war against the powers of Nature.
Like its many creations, one such was the Homo sapiens. Having gone through a millennia of evolution, they stand today at the brink of their society's collapse as they are loosing their war against Nature.
As be it, Nature designed every animal, such that they could choose to connect, form attachments, experience pleasure and procreate. There were no hard and steadfast rules in Nature: Mendelian genetics did not apply to all species, brains were forever evolving, no animal's appearance remained the same, no animal displayed consistency in whom they were attracted to, throughout their existence. Every entity, every energy had its flow.
We are amidst a war against individuals whom we feel uncomfortable around as they do not prescribe to our rules as to what they should look like, instead they are authentic in every manner Nature designed them to be.
Before I delve into debunking some of these high-school Biology concepts we hold dear to our heart, let us take a look at the dictionary.
From homosexuals to transgenders, every individual that prescribes to anything this human society terms as unnatural, are now being condemned. There was even a time when the term, Heterosexual was considered as a slur.
But this is far from the truth.
You see it is natural for individuals to exhibit a varied set of a mating behaviors and lifestyle choices, for that is the mark of a highly evolved species. We hear a lot of criticism on the basis of "biology".
I will be challenging this ideology of Amatonormativity in 4 sections, the first from a Chromosomal POV, while the rest from a Behavioral Neuroendocrinological POV:
Sex and Gender (Chromosomal View)
Transgender and Transexual studies (Neuroscience View)
Attraction/ Sexual Partner Preference (Neuroscience View)
Pair-bonding: Monogamy or Non-monogamy (Neuroscience View)
Sex and Gender
Gender cannot be defined by chromosomes (X and Y) for it is a highly complex social construct that develops from interactions of genes, chromosomes, hormones, internal sex organs and external secondary sexual characteristics with the environment: the roles individuals are conditioned to play, the roles they'd like to play, how they are socialized, stereotypes and sexism they have been exposed to, and even religion and faith based systems they are surrounded by.
Sex is also non-binary for people cannot be characterized as Male or Female, as there exist various chromosomal combinations: 46 XX, 46 XY, 45X, 47XXY, 47XYY, 47XXX, 48XXXX, 48XXXY, 48XXYY, 49XXXXX, 49XXXXY.
To solely assume an identity for an individual based on their external sex organs such as a penis and or a vulva, completely disregards 2% of the population that are born as intersex, with ambiguous genitalia at birth, Micropenis, clitoromegaly (an enlarged clitoris), partial labial fusion, undescended testes (which may turn out to be ovaries) in boys or even labial or inguinal (groin) masses (which may turn out to be testes) in girls, which often get misinterpreted and assumed so that one can be socialized into the narrative of the Sex Binary.
Transgender and Transexual Studies
If you aren't fully convinced regarding my arguments on interpreting gender and sex, let us try the Neuroscience approach.
1995, Transexual Study
Scientists: Zhou, Hofman, Gooren and Swaab
Study Design:
The brains of transexual individuals (those who have gone through a gender affirming surgery) and their cis-gender counterparts were analyzed: brains of trans and cis males; trans and cis females were being compared with each other.
Observation:
They concentrated on the part of the brain called Bed Nucleus Stria Terminalis (BNST) in the hypothalamus. It was found that BNST for males was larger than females. Furthermore, for trans-males (Female-Male surgery), the size of their BNST resembled the cis-males, and for trans-females (Male-Female surgery), the size of their BNST resembled the cis-females.
Conclusion:
It was quickly concluded that because of the hormonal surgery, their brains had altered itself to identify as their cis-counterparts.
However, that was far from the truth.
Ever since 1995, we have had several studies [(Carrillo B., et.al. 2010), (Chung WC, De Vries 2002), (Kiyar, et.al. 2020), (Ristori J, et.al. 2020)], all arriving at the same conclusion: The brain acknowledges your Gender change irrespective of hormonal involvement.
Transgender v Transexual Study
Study Design:
The brains of transexual and transgender individuals were analyzed, to observe if hormones play a role in determining the size of the BNST: brains of transexual and transgender males were analyzed, followed transexual and transgender females.
Observation:
Both transexual and transgender counterparts had the similar BNST structures.
Conclusion:
Even in transgenders, there exist a change in BNST. One doesn't have to undergo gender affirming surgeries to indicate such change. The brain recognizes that an individual has changed their gender and changes the size of the BNST accordingly.
Attraction/ Sexual Partner Preference
This Amatonormative society would have us believe that we should exist solely in a heteronormative fashion. However, our brain disagrees. We'll be concentrating on a brain region called the Sexually Dimorphic Nucleus of the Preoptic Area (SDN-POA). In humans, its also called the Interstitial Nucleus of the Anterior Hypothalamus (INAH- 3) Cluster.
1978 Testosterone and Sexual Differences in the Brain
Scientists: Gorski, Gordon, Shryne, Southam
Study Design:
Volume of the medial preoptic nucleus was measured in male and female rats. Various experiments were conducted which included injections of estradiol, progesterone or testosterone to the experimental groups; gonadectomy was also conducted to compare castrated and intact rats.
Observation:
Male rats had a larger mPOA than females. All the other hormonal injections had no impact on the volume of this region, except for Testosterone. Castrated males have a smaller volume than the intact males.
Conclusion:
Sexual differences in the brain develop due to the levels of Testosterone during development.
Soon, researchers proved that the size of the SDN-POA infers male-typical (mounting)/female-typical (lordosis) sexual behaviors. When injected with testosterone, females would mount other females and in castrated males (absence of testosterone), a display of lordosis in the presence of another male was observed.
It was also noted that the Testosterone injection only had an impact at a certain developmental stage.
Apparently, when the foetus is exposed to higher amounts of their mother's Testosterone during development, they grow a larger SDN-POA, and display male-typical behaviors such as attraction to females, mounting, etc.
When they are exposed to smaller amounts of their mother's Testosterone during development, they grow a smaller SDN-POA, and display female-typical behaviors such as attraction to males, lordosis, etc.
1991 INAH Dissection studies
Scientist: LeVay
Study Design:
Several heterosexual and Homosexual male cadavers' brains were sectioned to quantify the volume of the INAH (same as SDN-POA but in humans)
Observation:
Hom-M SDN-POA was smaller than a Het-M.
Conclusion:
Levels of testosterone during foetal development must have been low for Hom-M, as their SDN-POA was smaller, and resembled a Het-F.
2008 Transgender Research
Scientist: Dick Swaab
Study Design:
Transgender male and female brains were analyzed beside their cis-counterparts
Observation:
Trans-M (Female> Male transition) INAH was similar to that of cis-M.
Trans-F (Male> Female transition) INAH was similar to that of a cis-F.
Conclusion:
Levels of testosterone does impact foetal development, however, doesn't define gender. If an individual identifies as Female, the brain supports that identification by presenting itself as it does in cis- Females, and the same holds true for Males. One doesn't need to go through a gender-affirming surgery for the brains to recognize the gender change.
Monogamy v Non-monogamy
The last on our list to tackle is the societal perception that all relationships should be pair-bonded, aka monogamous in fashion. Now I shall address this in 2 parts:
Neuroscience
Promiscuous Morphology
Neuroscience
Au contraire to popular belief, there isn't one idealized manner of forming pair-bonds. As it would have it, Nature has designed us to bear both the monogamous and the non-monogamous alleles.
When we talk about the Neurological correlates behind these lifestyle choices, we are referencing the Vasopressin receptor (AVPR1a) on Dopamine neurons (D1 and D2).
So far we have discovered that having the AVPR1a gene, makes an animal monogamous/more likely to form pair-bonds. This Vasopressin receptor however, is expressed on Dopamine neurons.
The D2 neuron is responsible for forming pair-bonds while the D1 is to maintain the formed pair-bonds.
For example, let us presume you are meeting your date for the first time...
If during the honeymoon phase, you express a lot of D2 neurons, then the neurotransmitter, Vasopressin binds to the AVPR1a receptors on the D2 neurons, causing you to form a Pair-bond.
For one to transition from a honeymoon phase to a full-fledged committed relationship, one needs to then decrease D2 neurons and increase the expression of D1 neurons. When that occurs, the neurotransmitter, Vasopressin binds to the AVPR1a receptors on the D1 neurons, causing you to maintain a Pair-bond.
Let's assume that during the honeymoon phase, your D2 neurons decrease in expression, then you will not form any pair-bonds. That interaction would solely be platonic or physical.
If after the honeymoon phase, your D2 neuronal expression doesn't go down and there exist little to no D1 neuronal expression, then you will not be able to maintain the pair-bond. The likelihood of you cheating becomes higher. You are also more likely to be addicted to the honeymoon phase, causing you to become a serial monogamist, hopping from one pair-bond to another.
Promiscuous Morphology
Let us talk about morphological evidences.
Testicle size: As we go from the pair-bonded to promiscuity in primates, the higher the promiscuity of the females of that species, the larger the testicle size. Humans lie in the middle of that graph allowing the females more flexibility to choose from being pair-bonded or promiscuous.
Female Vocalization: Sex noises (moans and screams) among females are common in those species where male-male sperm competitions generally occur. For these sperm competitions to take place, females are rather promiscuous.
Kamikaze Sperm Hypothesis: In species that engage in sperm competitions, there exists these Kamikaze sperms, which constitute to about 40% of the sperms in one ejaculate. Their main purpose is to plug the vaginal canal, to prevent the flow of another man's sperm up the fallopian tube.
Semen Displacement Theory: The human penis is so designed that it can scoop out the sperms left behind by the woman's previous lover, and substitute its own semen in the canal. The last man standing has an evolutionary advantage to pass on is seed.
To encapsulate, humans cannot exist on amatonormative platform for Nature has provided them with so many options for connecting, forming attachments, experiencing pleasure and birthing the next gen. Utilize your naturally provided Autonomy!
Baker, R.R., Bellis, M.A. (2006). “Kamikaze” sperm in mammals? (1988). In: Shackelford, T.K., Pound, N. (eds) Sperm Competition in Humans. Springer, Boston, MA. https://doi.org/10.1007/978-0-387-28039-4_5
Brake, E. (2012). Minimizing marriage: Marriage, morality, and the law. Oxford University Press.
Carrillo, B., Gómez-Gil, E., Rametti, G., Junque, C., Gomez, A., Karadi, K., Segovia, S., and Chung WC, De Vries GJ, Swaab DF. Sexual differentiation of the bed nucleus of the stria terminalis in humans may extend into adulthood. J Neurosci. 2002 Feb 1;22(3):1027-33. doi: 10.1523/JNEUROSCI.22-03-01027.2002. PMID: 11826131; PMCID: PMC6758506.
DF Swaab (2004) Sexual differentiation of the human brain: relevance for gender identity, transsexualism and sexual orientation, Gynecological Endocrinology, 19:6, 301-312, DOI: 10.1080/09513590400018231
Garcia-Falgueras A, Swaab DF. A sex difference in the hypothalamic uncinate nucleus: relationship to gender identity. Brain. 2008 Dec;131(Pt 12):3132-46. doi: 10.1093/brain/awn276. Epub 2008 Nov 2. PMID: 18980961.
Gorski RA, Gordon JH, Shryne JE, Southam AM (1978) Evidence for a morphological sex difference within the medial preoptic area of the rat brain. Brain Res 148:333–346. Guillamon, A. (2010). Cortical activation during mental rotation in male-to-female and female-to-male transsexuals under hormonal treatment. Psychoneuroendocrinology 35, 1213–1222.
Harcourt, A. H., Harvey, P. H., Larson, S. G., and Short, R. V. (1981). Testis weight, body weight and breeding system in primates. Nature, 293:55. doi: 10.1038/293055a0
Hofman MA, Swaab DF. The sexually dimorphic nucleus of the preoptic area in the human brain: a comparative morphometric study. J Anat. 1989 Jun;164:55-72. PMID: 2606795; PMCID: PMC1256598.
Hostetler CM, Hinde K, Maninger N, Mendoza SP, Mason WA, Rowland DJ, Wang GB, Kukis D, Cherry SR, Bales KL. Effects of pair bonding on dopamine D1 receptors in monogamous male titi monkeys (Callicebus cupreus). Am J Primatol. 2017 Mar;79(3):1-9. doi: 10.1002/ajp.22612. Epub 2016 Oct 18. PMID: 27757971; PMCID: PMC5474115.
Houtsmuller EJ, Brand T, de Jonge FH, Joosten RN, van de Poll NE, Slob AK. SDN-POA volume, sexual behavior, and partner preference of male rats affected by perinatal treatment with ATD. Physiol Behav. 1994 Sep;56(3):535-41. doi: 10.1016/0031-9384(94)90298-4. PMID: 7972405.
Kiyar, Meltem, Collet, Sarah, T’Sjoen, Guy and Mueller, Sven C.. "Neuroscience in transgender people: an update" Neuroforum, vol. 26, no. 2, 2020, pp. 85-92. https://doi.org/10.1515/nf-2020-0007
LeVay, Simon. A Difference in Hypothalamic Structure Between Heterosexual and Homosexual Men. Science. August 30, 1991, Vol. 253, No. 5023, 1034-1037.
LeVay, S. (1996). Queer science: The use and abuse of research into homosexuality. The MIT Press.
Maslin, M., & Leakey, R. E. (2017). The Cradle of Humanity: How the Changing Landscape of Africa Made Us So Smart: Oxford University Press.
Parker Geoff A.2020. Conceptual developments in sperm competition: a very brief synopsis. Phil. Trans. R. Soc. B3752020006120200061
Ristori J, Cocchetti C, Romani A, Mazzoli F, Vignozzi L, Maggi M, Fisher AD. Brain Sex Differences Related to Gender Identity Development: Genes or Hormones? Int J Mol Sci. 2020 Mar 19;21(6):2123. doi: 10.3390/ijms21062123. PMID: 32204531; PMCID: PMC7139786.
Simmons LW, Fitzpatrick JL. Sperm wars and the evolution of male fertility. Reproduction. 2012 Nov;144(5):519-34. doi: 10.1530/REP-12-0285. Epub 2012 Sep 14. PMID: 22984191.
Simmons, L. W., Firman, R. C., and Rhodes, G. (2004). Human sperm competition: Testis size, sperm production and rates of extrapair copulations. Anim. Behav. 68, 297–302. doi: 10.1016/j.anbehav.2003.11.013
Zhou, J., Hofman, M., Gooren, L.J., and Swaab, D.F. (1995). A sex difference in the human brain and its relation to transsexuality. Nature 378, 68–70.