The debate on sexual orientation has been going on for a long time in the world. There are many researches some claiming that the homosexual people are socially assimilated towards being homosexual from the social environment. There are others who hold to the opinion that it is entirely a hormonal aspect that develops as one grows. There are those who take a position in between the two and belief that gender and sexual orientation are as a result of the interplay between the environment and the genetic and hormonal state of the individuals. As it was learned recently, the hypothalamus plays an important role in determining one’s sexual orientation and gender identity. Therefore, this paper seeks to establish the hypothalamic structure between heterosexual and homosexual men as supported by researchers.
Alicia Garcia-Falgueras and Dick F. Swaab (2008) carried out a research on a sex difference in the hypothalamic uncinate nucleus, relationship to gender identity. The results showed that the brain weight of those who identified as transsexuals had a brain weight between that of the males and that of the females i.e. 1358 ± 155.6 of the transsexuals, while that of the males was (1529 ± 231.4) and the females was 1244 ± 160.5). Although they proceeded and clearly showed that, when all the subjects where pulled together, there was no any significance relationship between the brain weight and the uncinate nucleus. The brain cells of the transsexual people been in between the one for heterosexual male and female may be construed to be a middle level that can deviate towards either side depending on the individuals social environment. In most scenarios, there are men who tend to affiliate themselves towards the feminine roles and vice versa. This is because it was established “The volume and number of neurons of the INAH3 as measured in thionin-stained sections, was found to be of female size in male-to-female transsexual people. The female-to-male transsexual subject had a male INAH3 volume and neuron number” Alicia Garcia-Falgueras and Dick F. Swaab, 2008. I agree to the fact as stated that the transgender people have hormones different from the heterosexual group. It is thus true that the sexual orientation of an individual depends on the functioning of the hypothalamus. Testosterone circulating in the body was also found to be of great important to gender identity.
It was also established that(as recorded in Alicia Garcia-Falgueras and Dick F. Swaab, 2008) “Some brain parameters in male-to-female transsexual people are typically female, such as the volume and neuron number in the BSTc (Zhou et al.,1995 and Kruijver et al., 2000), and in the INAH3 subdivision, but other parameters are rather like those found in males, indicating a sex-atypical development” Alicia Garcia-Falgueras and Dick F. Swaab, 2008. It is thus apparent that sexual development takes place in the brain of an individual.
The Gonadotropin-releasing hormone (GnRH) that is located in the hypothalamus releases the hormone that helps in control of sexual and reproductive functions in the body such as pregnancy and lactation i.e., milk production. Swaab D.F., Gooren L.J.G. and Hofman M.A.(n.d) noted that although, their research did not agree with the common theory that sexual orientation is as a result of interaction from the brain and the social environment, they found that there was a difference in the number of Suprachiasmatic nucleus (SCN) cells between the homosexual men and heterosexual men. The homosexual men have a double the size of cells the control group had. Since sexual differences are found in the SCN cells, the differences in homosexual men can be taken as having an influence on the sexual orientation in men.
Therefore, hypothalamus can be taken to some extent to be responsible for sexual orientation. The differences as articulated above supports this. However, the levels of influence has not yet been established.
In conclusion, although the hormones play a key role in sexual orientation, the effects of the social environment cannot be entirely dismissed. The two interplay at different scales in different social environments and influence sexual orientation and gender identity. However, the scientific research on these issues has to be furthered and more evidences provided so as to ascertain the actual causes of differences in gender identity and sexual orientation.
Work cited
Swaab D.F. · Gooren L.J.G. · Hofman M.A. Gender and Sexual Orientation in Relation to Hypothalamic Structures Horm Res 1992;38:51–61 (DOI: 10.1159/000182597)
Susanne Hiller-Sturmhöfel, and Andrzej Bartke. The Endocrine System. 1998
Alicia Garcia-Falgueras and Dick F. Swaab . A sex difference in the hypothalamic uncinate nucleus: relationship to gender identity. 2008
