A recent occupation concerns the characterization of sexual orientation as a “fluidity” that will necessarily lead to the abandonment of the “primary binaries,” male and female altogether. Needless to say, at face value, the idea is disconcerting. Yet, while there is certainly an abundance of discussion regarding sexual orientation as an anthropological (and do not confuse this with any theological, Orthodox construct of the human άνθρωπος as we would understand it), sociological, the feminist, the queer, and no discussion would be complete without Claude Lévi-Strauss, for whom it was all binaries, there is nothing of the biogenetic. In fact, human medicine would point us to the variety of disorders that constitute the biological confusion that is intersex disorders. This, it would seem to me, answers the question as to whether homosexual orientation has any bearing whatsoever in regard to – not an ontological reality – a purely social construct, “primary binaries.” It seems you can have your binaries & be homosexual too… or something like that.
The emergent state of human genetics is the examination of the complex, and at this point in our in knowledge and technology, nearly impossible task of the role of the interaction of genetics and everything outside the genome: human beings as psychological, environmental, social, and spiritual beings. And this is referred to as epigenetics. We are beginning to understand that many – perhaps if not the majority – of what we otherwise understood as “familial,” inherited, or genetically-influenced human characteristics are “activated” only by, or in the absence of, an external, extra-genomic event(s). While this discussion is not specifically focused on epigenetics, as we shall see, I will point out one recent example utilized by Dr. Richard Francis, who weaves the theme of the epigenetic effects of the Dutch famine of World War II on their current rate of obesity through his examination of the emerging science. We will undoubtedly see more and similar data explored.
The point is that we will describe, then, three distinct stages; two that we know for certain are essential for the differentiation of gender: 1) the genetic (meaning the combination of equal genetic material contributed by each parent to form our complete genomic code), and 2) the post-genetic but still pre-natal (intra-uterine) stage, notably hormonal. The third stage, the post-natal, epigenetic, probably has no direct bearing on the determination of gender , but it appears, as has been suggested to play an essential role in far reaching human characteristics and disease, including homosexuality. This last point is for another separate discussion(s).
With such an introduction it seems ludicrous to to even point out, but to date, there are no significant data that would suggest that there is any perinatal, post-natal, or post-delivery environmental event(s) with a putative role in the formation of sexual orientation in men or women. Mind you, there are those who have canonized what are hallmarks of psychoanalytic theory – and I refer here to those engaged in reparative therapies – by placing them in cheap suits and creating a “treatment industry.” Examples of these post-natal “events” are same-gender psychoanalytic (absent, distant, invasive, or “boundary-fluid” parent); similarly characterized but opposite–gender parent; attachment disorders; childhood trauma (physical, psychological, sexual); absent or poor same-gender modeling (e.g. a boy raised by a homosexual father(s), a girl by a lesbian mother(s)); or (same-gender) sibling “modeling” homosexuality to younger siblings. The problem is that canonization in science requires evidence, replication, replication, and… more replication. In other words, to the best of our knowledge, it is true (read the difference between science & anecdote here). There is no clear and convincing evidence that anything that happens after you are born influences your sexual orientation. In that we have invested some time in exploring the genetic influences involved in both gender distinction and sexual orientation, I would like to focus on the second stage of development, post-genetic intra-uterine events occurring prior to birth.
As was the case with the basic human genetics, this, again, is not the appropriate venue to teach human embryology & endocrinology. Suffice it to say that the basic knowledge and models upon which we will draw rely upon knowledge common to the animal world in general. In making this acknowledgment, we therefore have access to a tremendous body of “canonized” scientific data. Thus, we can clearly state that in the overwhelming majority of cases, the process of sexual gender differentiation in the course of the developing fetus is relatively “unremarkable,” in as much as we are considering an extraordinarily remarkable process. However, in what was seen as the process of hormonally-induced distinction resulting in a conceptual “binary” of genital morphology (aye!) – the culminating, eventual internal/external genitalia that distinguish males from females – is anything but simple. Wow. And to what, exactly, might we refer?
We have long known that the hormonal differentiation of gender is the result of the presence or absence of “cascades” of steroidal sex hormone (testosterone), but importantly, this hormonal event will not determine sexual behaviour. This is most likely the result of two distinct, separate periods in gestational life where genital structure and steroidal action in the brain are other than simultanéous; for example, a male embryo could theoretically be exposed to elevated levels of testosterone early in gestation – resulting in normal development of the genitalia – but a decreased level at a point of the final development of typical sexual orientation. A number of recent studies comparing homosexual and heterosexual populations exposed to atypical hormonal conditions during their development suggest a likely possibility. :
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As sexual differentiation of the brain takes place at a much later stage in development than sexual differentiation of the genitals, these two processes can be influenced independently of each other. Sex differences in cognition, gender identity (an individual’s perception of their own sexual identity), sexual orientation (heterosexuality, homosexuality or bisexuality), and the risks of developing neuropsychiatric disorders are programmed into our brain during early development. There is no evidence that one’s postnatal social environment plays a crucial role in gender identity or sexual orientation.
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We combine these data with existing data regarding the genetic influences in the hormonal influences of female fecundity of “mothers, maternal grandparents, and maternal aunts), [of homosexuals] compared to the corresponding relatives of heterosexual controls” such that “The number of women with extreme skewing of X-inactivation was significantly higher in mothers of gay men (13/97=13%) compared to controls (4/103=4%) and increased in mothers with two or more gay sons (10/44=23%). Our findings support a role for the X chromosome in regulating sexual orientation in a subgroup of gay men.” . It seems reasonable to conclude that a separate, distinct process of post-genetic, yet prenatal hormonal events are responsible in a yet undetermined fashion to suggest it is “possible that the hormonal imprinting that takes place at these two time periods is substantially different” :
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Behaviour genetic investigations provide strong evidence for a heritable component to male and female sexual orientation. Linkage studies are partly suggestive of X-linked loci although candidate gene studies have produced null findings. Further evidence demonstrates a role for prenatal sex hormones which may influence the development of a putative network of sexual-orientation-related neural substrates. However, hormonal effects are often inconsistent and investigations rely heavily on ‘proxy markers’. A consistent fraternal birth order effect in male sexual orientation also provides support for a model of maternal immunization processes affecting prenatal sexual differentiation.
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It would seem appropriate to conclude that the binaries are safe, for the moment, and that we have added insight into the complex factors that may result in the genetically-influenced hormonal differentiation of both sexual gender differentiation, as well as sexual orientation differentiation.