Written by: Leylie Meh
Edited by: Noa Doupe
Despite decades of research there is still long standing disagreement as to how individuals understand sexuality amongst human beings. Due to societal prejudices, homosexuality was included in the Diagnostic and Statistical Manual of Mental Disorders until 1973. Homosexuality had a relatively dynamic title, with its label changing approximately four times during its residence in the manual. The removal of the label as a mental disorder was both a product of gay activism movements in the late 1900s and developments in psychological research. As some Western societies have begun to break down their prejudices against homosexuality, scientists have begun to research its biological origins. A plethora of studies have been conducted in an attempt to discover what determines an individual’s sexuality. Some biologists have considered whether heredity plays a role in it by studying families. Some studies have shown that there is a common pattern of siblings being more similar in sexual orientation than expected by chance. Sexuality being a biological trait addresses the long standing debate of whether or not sexuality is a choice, which fuels many sociological disagreements. The development of empirical evidence becoming an explanation for varying sexualities could become a revolutionary scientific finding, as well as a way to silence baseless claims labelling homosexuality as a phase, choice or sin. The following paragraphs will challenge the psychological binary of nature versus nurture by exploring the emerging research of foetal epigenesis, ultimately revealing how environment influences personal traits.
Scientific Evidence
Various research has proved that a trait like sexuality cannot be purely genetic. Rather, sexuality is a complex trait that is influenced by a variety of factors including hormones, genetics, and environmental influences. Some researchers are leaning towards foetal epigenesis as a potential factor in influencing sexuality. In order to understand this argument it is essential to understand: what is epigenesis and why does this affect aspects of human behavior? Epigenesis is the process of genetic tagging which ultimately inhibits or enhances gene expression. Our DNA is wrapped around proteins called histones, as seen in the image below.
When exposed to different environmental factors, chemical compounds attach themselves to the histone tails. When these chemical compounds are attached it causes the chromatin (strand of DNA) to be wrapped either more tightly or loosely around the histone. This is relevant because when translation occurs (the process of DNA being transcribed into mRNA) the level to which the chromatin is exposed influences which parts of the DNA are translated. Thus affecting gene expression, which can in turn influence psychological behavior. Epigenesis occurs as the intersection of nature versus nurture in psychology, this being the intersection between the innate traits of individuals and their experiences. This is because it is a biological modification made as a product of exposure to environmental factors such as odor pollutants, pathogens, heavy metal toxins, and diet. Foetal epigenesis is when fetuses are exposed to toxins in the womb, which affects how their brains, organs and behaviours might develop, in some cases resulting in some long lasting effects. Hence, people exposed to the same environmental factors can produce similar traits (like similar sexualities amongst siblings).
Previous Research
There have been some case studies that look at the potential effects of foetal epigenesis on sexuality. One example of this is a study published by the National Library of Medicine by William R Rice et al. It explored the commonalities of homosexuality amongst men and women, and how recent pedigree and twin studies suggest that homosexuality might be heritable. It explained the curiosity of the causality of epigenetics, because monozygotic twin studies have been conducted in the past, but both twins aren’t always homosexual. This means homosexuality can’t be genetic, because monozygotic twins come from one zygote and have 100% of the same genetic makeup. It highlights the point that foetal androgen signalling strongly influences sexual development– as foetuses with XX chromosomes are less sensitive to androgen (male hormones) than fetuses with XY chromosomes. In simpler terms, sexuality may be influenced by hormones from the mother during foetal development. If the parent is having a child of the opposite sex, these epigenetic markers could be passed over, rather than being erased. This means that as the foetus develops these epigenetic markers from the parents remain with the child, as opposed to being erased. The pass over of these epigenetic markers would cause the child to develop more features of the opposite gender including sexual attraction.
Another study conducted by Vilain and Nguyen at UCLA analyzed DNA samples of 37 monozygotic male twins. The results indicated that there were nine epigenetic markers common amongst the homosexual males in comparison to their identical brothers. Using this finding, they found two influencing factors determining homosexuality amongst males: one being fraternal birth order and another being mothers experiencing prenatal stress. In relation to fraternal birth order, they concluded that the more males that a mother birthed, the higher chance that the proceeding son could be homosexual. This again suggests foetal epigenesis to be a biological explanation, as stress is a factor that leads to epigenesis. Both of these findings were however only indicated valid for males and did not hold true for females, potentially indicating an empirical gap in this theory. The reason for this is because it is only applicable when the parent birthing the child is biologically the opposite sex, making this theory only possible to be applicable to males. Notably, both of these studies are just examples of emerging research– there is not sufficient evidence to confidently confirm that homosexuality is a product of epigenetics, but rather a stage of inductivism when looking at the potential biological components of sexual orientation.
Implications
When looking at these emerging theories, the validification of homosexuality could be a groundbreaking theory in society potentially revolutionizing the concept of equitable socio-political societies. Homosexuality has faced severe prejudice in many societies, and to this day experiences extreme scrutiny in some countries with religious regimes. Having empirical evidence could end the long standing stigma of homosexuality being a choice and a sin. The discovery could also potentially reduce the severe mental health implications that many homosexual individuals face. Research suggests that 24 to 41% of queer individuals experience suicidal ideation. Some causes that contribute to these outcomes are feelings of exclusion, social rejection, and familial rejection. Discovering that homosexuality is a biological feature, similar to heterosexuality, could contribute to a decrease in intensity of these factors, potentially also easing the mental health crisis amongst youth and older generations.
However, there are some potential disadvantages of discovering a biological basis of homosexuality. Some communities that have strongly internalized prejudice towards the LGBTQ+ community could use it as an opportunity to search for a “cure” as a form of conversion therapy, which could be extremely dangerous for queer individuals. Homosexuality could be relabeled as a diagnosable disorder, as it previously was in the DSM during the 1900s. This would again cause more social damage for queer individuals. As such practices could render queer individuals increasingly vulnerable to physical and mental health challenges.
Epigenetics is an emerging biological component that broadens the scope of how society views and acknowledges identity. Identity can no longer just be viewed as a sociological product of a person’s environment, choices and experiences, but rather a combination of innate biological factors and how they influence an individual to interact with their environment. Despite the fact that science is purely empirical, this evidence can also be used as a way to broaden perspectives, increase empathy and protect and validate communities that have been marginalized for many years. However it is still unknown as to whether this information will be embraced openly or is still vulnerable to scrutiny. Ultimately, it can be seen that there is an emerging research pointing to the fact that homosexuality is a combination of innate biological traits and personal experiences, rather than a choice.
Bibliography
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