Biological Causes of Homosexuality - Term Paper Example

Biological Causes of Homosexuality Biological Causes of Homosexuality Introduction Homosexuality has been a topic for debate for centuries. Some people still strongly believe that homosexuality has some cultural, social, and political backgrounds. The existence of such myths could be attributed to lack of researches on the subject and ignorance on gender specific roles and traits. It seems that different cultures observe the trait of homosexuality in extremely different ways since few researches have been performed to explore the contributory factors to this trait. The rights of homosexuals are gradually turning out to be equivalent to those of heterosexuals in the United States. In my opinion, homosexuality is a biological trait. This paper will present some theories and other empirical evidences to prove the biological influence on homosexuality. Homosexuality An indisputable fact about humanity is that every individual owes their existence to the physical union between their father and mother, and this reality forms the basis for the concept of family. However, anthropologists clearly point out that the existence of homosexuality has been identified in some societies at different degrees of prevalence throughout the history. The trait of homosexuality can be simply defined as the sexual attraction between the individuals of the same sex. A homosexual person in the male gender is called ‘gay’ while the term ‘lesbian’ represents a homosexual female. Over the past three decades, the number of homosexuals has dramatically increased and such trait has increasingly grown to be mainstream and open. According to some major studies (Billy, Tanfer, Grady and Klepinger, 1993), nearly 2% to 13% population in the modern western society is homosexual or has had some kind of homosexual relationship during their lifetime. Many of the religions perceive homosexuality as sinful trait. Although a large number of countries have legalized homosexuality, some countries award imprisonment and even death penalty to homosexuals. Biologic influence on homosexuality Nowadays, homosexuals strongly claim that this behavior is an innate characteristic like race or gender and some recent biological studies support their argument. In recent days, scientists reflect that causes of homosexuality trait could be attributable to genetic, hormonal, and neuroanatomic elements. “It would be difficult to envisage a change in the prevalence of a genetic trait merely in response to changing cultural norms” (Baron, 1993). Baron points out that culture has little influence on homosexual behavior. The following part illustrates different study results that support the argument that homosexuality is a biological trait. 1. Genetic studies Kallmann’s study in 1952 was one of the most frequently cited studies about homosexuality. Jaz reports that on the basis of obtained outcomes, Kallmann reported a cent percent “concordance in identical twins for homosexuality” whereas the identified concordance in fraternal twins was only twelve percent. From this experiment, he concluded that identical twins possess an identical genetic code and it adds to homosexual behavior. Another genetic study on homosexuality published by Bailey and Pillard got high media coverage as it had reflected the biological influence on homosexuality. “Fifty-six pairs of identical twins, fifty-four pairs of fraternal twins, one hundred and forty-two non-twin brothers of twins and fifty-seven pairs of adoptive brothers” (Jaz, Bailey and Pillard (n.d). The obtained outcomes were strong enough to change the social norms regarding homosexuality. The study showed that the concordance rate of homosexuality was eleven percent for adoptive brothers, who were genetically unrelated whereas the rate was nine percent for non-twin biologic brothers. In addition, the fraternal twins showed a concordance rate of twenty-two percent for homosexuality while the rate was fifty-two percent for identical twins. This study proved that genetics play a vital role in passing homosexual behavior to next generation. Jaz points out a research conducted in 1993 strongly pointed out a notable relationship between homosexuality in individuals under study and “inheritance of a genetic marker on the X-chromosome”. This study report also attained considerable media coverage. Although different genetic studies conducted over the last three decades had many limitations, most of them expressed the view that homosexuality had been affected by genetic factors. 2. Hormonal studies Many researchers are of the view that hormonal variations during prenatal life may be a crucial factor in determining sexual preference in humans and they use study outcomes obtained from rat and pig experiments to justify their claim. Those experiments focused on the aspect that sex hormones have a significant effect on the brain development, specifically the area known as hypothalamus. Investigators injected female rats with male hormones prenatally and they observed that female rats had exhibited male sexual traits during their adulthood. Similarly, when male rats were prenatally injected with a steroid drug, they showed the female sexual behavior. Based on such studies, many scientists theorized that the homosexual behavior may result from prenatal hormonal derangements. According to the hormonal theory of sexuality (as cited in Barry, 2010), certain hormones influence sexual orientation that develops later in an adult. Gerianne M. Alexander, Assistant Professor of Psychology at Texas A&M University, argues that hormones could be a root cause for homosexuality. He points that girls with high levels of adrenal androgens show greater aggression, more masculine preferences, and an increased rate of homosexual behavior. Some other investigators have found robust dissimilarities between the brains of homosexual and heterosexual persons. The BBC News reported in an article by Martin Hutchinson (2003) that the prevalence rate of polycystic ovary syndrome symptoms was nearly 80% in lesbian women while only 32% of heterosexual women had shown such symptoms. 3. Neuroanatomic studies In 1991, a new study report was published on the size differences in a region of the hypothalamus know as INAH3 between homosexual men and heterosexual women. In order to justify the argument, it was pointed out that homosexuals are more vulnerable to AIDS deaths than heterosexuals. By focusing on this fact, the proposers claimed that HIV may affect brain tissues including hypothalamus and thereby they linked the influence of sexual orientation on AIDS deaths with the anatomical difference in INAH3 between homosexual men and heterosexual women. Similarly, another research conducted on neuroanatomic effects on homosexuality asserts that a brain structure called anterior commissure is notably larger in homosexual men than in heterosexual men. D.F Swaab’s studies also support the anatomical differences in the gay men’s brain structure. In addition to these, many other investigators have identified the difference in brain structure between homosexuals and heterosexuals. Since the hypothalamus relates to sexual drive and function, this structural difference contributes to the biological roots of homosexuality. 4. Psychological studies As Johnson (2003) reports, in 1957, Karen Hooker conducted the first psychological test to explore the biological roots of homosexual behavior. For this study, Hooker tested a group of homosexuals and heterosexuals who were matched for age, education level, and IQ. Hooker executed three psychological tests including the Rorschach, Thematic Appreciation Test, and the Make-A-Picture-Story Test (MAPS). Psychologists interpreted the test results and tabulated them. The study results showed that both the groups performed very similarly in all three tests, and hence Hooker concluded that homosexual trait is not a psychological disorder. Conclusion In short, homosexuality is a biological trait. Genetic, hormonal, neuroanatomic, and psychological studies indicate that no external factors influence this behaviour other than biological elements. In addition, psychological studies on homosexuality reflect that this behavior is not a mental disorder. References Billy, J. O. G, Tanfer, K, Grady, W. R & Klepinger, D. H. (April 1993). The sexual behavior of men in the United States. Family Planning Perspectives, 25(2), 52. Baron, M. (07 August, 1993). Genetic linkage and male homosexual orientation. British Medical Journal, 307(6900), 337-338. Barry, M. (January 2010). Gay twins and the science of epigenetics. The Science of Homosexuality, 1-25. Retrieved from http://fc08.deviantart.net/fs71/f/2010/036/7/3/The_Science_of_Homosexuality_by_inspiredcreativity.pdf Hutchinson, M. (30 June, 2003). Hormone link to lesbianism. BBC News. Retrieved from http://news.bbc.co.uk/2/hi/health/3032454.stm Johnson, R. D. (30 April, 2003). Homosexuality: Nature or nurture. AllPsych Journal. Retrieved from http://allpsych.com/journal/homosexuality.html Jaz, T. I. (n.d). Homosexuality: An analysis of biological theories of causation. Retrieved from http://www.flyfishingdevon.co.uk/salmon/year2/hormones/tahir.htm#ref8 Read More