Sexual Orientation of a Person - Case Study Example

 Factors influencing Sexual Orientation ‘What decides one’s sexual orientation?’ seems to be an uncomplicated question but the answer may not be as simple. Sexual orientation of a person is a complex phenomenon that combines romantic, emotional, demonstrative, and sexual attraction to another person. Sexual orientation is not just sexual behavior because it incorporates an individual’s feelings and identity. In addition, this sexual orientation can also influence the lives of their family and friends. When one focuses on the causes for this particular sexual orientation among males and females, various factors such as biological factors, parenting styles, childhood experiences, and others are said to play a contributing role. Although, social factors like parenting styles and childhood experiences are maximally focused by various sections including social scientists, media, and common people, the role of biological or physiological factors assumes prominence based on number of researches. The article titled Prenatal Endocrine influences on Sexual Orientation and on Sexually Differentiated Childhood Behavior, written by Melissa Hines, and a book titled Gay, Straight and the Reason Why, written by Simon LeVay, focuses on this role of biological factors. So, this report analyses the above mentioned article and the book about sexual orientation to develop a plausible biological-based scientific explanation for the development of diverse sexual orientations in humans. LeVay in his book extensively covers topics regarding the factors responsible for sexual orientation. It includes prenatal neuro-hormonal effects, gender related brain organization in humans, cultural, psychological, and genetic influences (LeVay, 2011). Prenatal neuro-hormonal effects focus on how fetus can be exposed to hormones during pregnancy thereby influencing their sexual orientation (McCarthy, De Vries & Forger, 2009). According to researches, organization of the brain in males and females can also sway sexual orientation (Manning, 2002). When individuals face or exposed to certain cultural aspects, they are shown to exhibit homosexual or heterosexual behavior (Zucker, 2002). If certain experiences from childhood have a psychological impact, individuals’ sexual orientation can be influenced (Bem, 1996). Apart from these causes, LeVay (2011) focuses on how genetics can also influence the sexual orientation. He claims prenatal and hormonal factors as the most important determinants for one’s sexual orientation (LeVay, 2011). Similarly, the article claims evidences for prenatal and neonatal exposure to gonadal steroids like testosterone and others as the main determinant for sexual orientation in humans (Hines, 2012). Both the sources extensively analyze the biological factors behind the development of varied sexual orientation in humans and are capable of providing sensible justification for the origins of variability in sexual orientation. As an empirical basis for hypothesizing that gonadal hormones play a significant role in determining sexual orientation in humans, other mammalian species were exposed to endocrinal experimentations and their behavioral sexual differentiations were studied. The brain and behavior of mammals were influenced by gonadal hormones in two ways, organizational and activational (Phoenix, Goy, Gerall & Young, 1959). Organizational effects are visible during prenatal and neonatal stages while activational effects are relevant during adulthood which is subjected to a transient response. An exposure to testicular hormones during the prenatal and neonatal stages resulted in a typical male development whereas absence of testicular hormones resulted in a typical female development. This was an evident phenomenon in rodents (Goy & McEwen, 1980). Treating female rats with testosterone during early stages resulted in increased volume of sexually-dimorphic nucleus of the preoptic area of the hypothalamus (Gorski, 1978). This effect in rodents proved to be applicable for humans in the research conducted by LeVay. In the research, LeVay proved that the INAH3, a structure in the hypothalamus of the brain that regulates sexual behavior, was comparatively small in homosexual men compared to heterosexual men (LeVay, 2011). LeVay also explained homosexual behaviors in other non human species like bonobos, breeding colonies of seagull species, domestic sheep, and others (LeVay, 2011). In few instances he also explains the bisexual potential of those species and tries to correlate the evidences observed in non-human primates with that of humans. When one focuses on the article, it mainly discusses about the various biological or physiology based factors that influence the sexual orientation in humans. Hines particularly focuses on the role of hormones. That is, the author states that prenatal administration of gonadal hormones and the resultant development of some prenatal disorders of sex development can influence one’s sexual orientation (Hughes, Houk, Ahmed & Lee, 2006). Studies conducted by measuring the hormonal levels in prenatal stage by examining the amniotic fluid proved to influence the later sexual orientation behaviors in humans (Warne, Faiman, Reyes & Winter, 1977). Some physical characteristics like finger ratios relate to prenatal androgen exposure (Manning, 2002). Studies also show that stress during the gestational period also plays a vital role in varying the androgen levels in a fetus which later influences its sexual orientation (Grumbach, Hughes & Conte, 2003). When mental related stress happens in pregnant females, it leads to number of changes not only in their own physical body but on the fetus as well. Speaking of androgen levels, Hines in the article talks about Congenital Adrenal Hyperplasia (CAH), which is a kind of disorder of sex development (DSD) that is responsible for overproduction of adrenal androgens (New, 1998). Such a disorder results in prenatal androgen elevation in female fetuses and subsequently results in genital virilization (Pang, 1980). Extensive researches conducted in CAH affected women resulted in similar kind of conclusions which laid emphasis on reduced heterosexual orientation. 20% of CAH women revealed their desire to maintain long term relationship with a female partner (Dittmann, 1992). The severity of CAH had varying influences in determining one’s sexual orientation. In null mutation condition, which is the most severe case of CAH, 50% of the women were either bisexuals or homosexuals (Meyer-Bahlburg, Dolezal, Baker & New, 2008). In the next most severe 12splice mutation condition, 30% of the women were homosexuals and in the least severe V281L mutation condition, 5% of the women were homosexuals (Meyer-Bahlburg, Dolezal, Baker & New, 2008). Some studies also proved asexuality in CAH affected women (Frisén J et al., 2009). This clearly proves the role of disorders of sex development in the determination of sexual orientation in women. Prenatal exposure to estrogen can also have significant influence in the later sexual orientation in women even though it does not result in genital virlization (Goy & Deputte, 1996). Earlier, Diethylstilbestrol (DES), a synthetic estrogen, was prescribed for pregnant women with a mistaken belief that this hormone would prevent miscarriage (Harry, 1982). When these women were subjected to research, it was proved that DES exposure resulted in reduced heterosexual behavior. That is, although it was prescribed for pregnancy related issues like miscarriages, it had an impact on the sexual orientation. In addition, despite it being a synthetic form of the gonadal hormone, the above pointed out research further proves the influence of gonadal hormones in determining sexual orientation in women. Analogous researches carried on men essentially need not produce similar results. Sexual orientation researches are distinct for men and women and what holds true for one gender need not hold true for the other. Prenatal exposure to ovarian hormones in men resulted in negative results (Kester, Green, Finch & Williams, 1980). Studies were conducted on men exposed to DES, natural progesterone, and also synthetic progestins (Meyer-Bahlburg, 1979). But, none of them proved for sexual orientation changes relating to the administration of these hormones. Other researches proved that such exposure did not result in evidences of reduced heterosexual orientation in men (Meyer-Bahlburg, Ehrhardt, Whitehead & Vann, 1987). Another research event that proved dissimilar results in men and women is the impact of prenatal stress in sexual orientation. Stress during pregnancy stimulates the adrenal hormone production which can influence the sexual orientation behavior (Beckhardt & Ward, 1983). However, teststosterone secretion from the testes of a male fetus can counterbalance this stimulation of adrenal hormone. On the other hand, female fetus lacks this ability and exhibits reduced heterosexual orientation (Bailey, 1991). Thus prenatal stress factors affect the sexual orientation behavior of women but not men. Sexual orientation in men is influenced by androgen secretion levels. A condition of androgen deficiency in males termed as Androgen Insensitivity Syndrome (AIS) result in the state where the external genitals do not get developed (Grumbach, Hughes & Conte, 2003). Due to this fact, though the chromosomal combinations are XY (male) for this kind of individuals, due to the lack of external genitals the individual is considered to be a female at birth. Only at the time of puberty, this deficiency would be discovered due to the absence of menstrual cycle which is result of the lack of internal female reproductive structures. Such a XY female would exhibit sexual attraction toward males rather than females (Money, Schwartz & Lewis, 1984). Another influence of prenatal androgen exposure is the 2D:4D finger ratio (Manning, 2002). This is the ratio of lengths of the 2nd and 4th finger of the hand. Generally this ratio is larger for heterosexual women whereas this ratio remains small for homosexual women. Also researches prove that homosexual men exhibit more feminine finger ratios than heterosexual males (McFadden, 2005). Another effect of prenatal androgen exposure is the size of the genitals. Homosexual men posses larger genitals when compared to heterosexual men ( Bogaert & Hershberger, 1999). Certain childhood behaviors also influence the sexual orientation of a person in later stages. 80 to 90% children play with partners of their own sex (Hines & Kaufman, 1994). This tendency of sex difference grows larger as the children grow older. Results of researches proved that high levels of cross-gendered behavior in childhood resulted in non-heterosexuality in men (Berenbaum & Hines, 1992). Extensive researches proved that extreme cross gendered behavior in childhood resulted in homosexual or bisexual orientation in adulthood (Green, 1987). Another research proved that children showed increased male-typical or decreased female-typical behavior where their mothers took androgenic progestins during pregnancy (Ehrhardt, Baker & Males, 1977). An opposite outcome was observed when the mothers took anti-androgenic progestins (Ehrhardt & Money, 1967) As an evolutionary biologist one should understand the fact that sexual orientation is a complex phenomenon that originates from a multi-factored pathway. The traditional single origin hypothesis will be no longer suitable in the research processes that deal with the biological factors causing diverse sexual orientation (McFadden, 2005). When an evolutionary biologist focuses on these multi-factors, it can provide them with newer perspectives about the causes behind the origin or even evolution of sexual orientation. At the same time researches on sexual orientation should be carried out keeping in mind that different genders respond in distinctive manners thus research methodologies must be framed considering the exclusive behavior of the genders (Titus-Ernstoff et al., 2003). Most researches are generally restricted to only two genders (male and female) and as an evolutionary biologist special emphasis must be laid on transgender sexual behaviors (Bartlett & Vasey, 2006). Based on the above discussion, it is possible to state that sexual orientation definitely is not a matter of choice. It seems to emerge from the earliest prenatal stage and gets well established within the adolescence. It is also the process that involves complex interaction of biological and cognitive activities. Though multiple reasons are claimed for one’s sexual orientation behavior like maternal interaction at early stages, media influences, and others more reasonable explanations could be developed by analyzing the sources used here. Both the article and the book provide in-depth discussion of varied factors. From which, we could conclude that development of sexual orientations (homosexual, heterosexual or bisexual) depend primarily on prenatal exposure to either greater or lesser amounts of gonadal hormones. References Hines, M. Prenatal endocrine influences on sexual orientation and on sexually differentiated childhood behavior. Frontiers in Neuroendocrinology 32(2), 170–182. Retrieved from: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3296090/ LeVay, S. (2011). Gay, straight and the reason why: the science of sexual orientation. Oxford, UK: Oxford University Press   Read More