The Science of Sexual Orientation

One of the most important issues in the modern society has beenhomosexuality. Although it is not a new phenomenon in humancivilization, it has attracted a lot of attentions in the recentpast. This is mainly due to changes the homosexual society, mainlythe advocacy of their rights, legalization of gay marriages in somecountries and the fact that homosexuality is not a secret in themodern world. Although majority of the human civilizations in thehistory of human kind disapproved homosexuality, there are evidencesthat same sex relationship were in existence throughout humancivilization. The recent wave of homosexuality in the modern societyhas rejuvenated the science of sexual orientation. It is an emergingfield of behavioral and medical research that seeks to establish thefactors that influence the development of sexual orientation. Thispaper looks at some of the factors that are considered by scientiststo be the factors that influence the development of sexualorientation. The paper is based on the book “Gay,Straight and the Reasons Why: ” byDr. LeVay and the article “sexual differences of the human brain:relevance for gender identity, transsexualism and sexual orientation”by Swaab.

Sexual orientation refers to the sexual attraction or sexualfeelings of a person towards another person. Majority of the peoplehave heterosexual orientation where they are sexually attracted topersons of the opposite sex. However, there are a minority group ofpeople with homosexual orientation. These people are generallyreferred to as homosexuals and include gays and lesbians. It isimportant to note that sexual orientation is a continuum such thatsome individuals are attracted to people of both genders. Moreover,some people identify themselves as gays or lesbian but are notinvolved in any homosexual activity. These people are referred to asbisexuals. Additionally, there are a wide distinction between sexualorientation and gender identity. While sexual orientation involvesemotional feeling, gender identity refers to the sense of being maleor female. In many societies around the world, sexual attraction andrelationships between people of the same gender is considered ataboo. Additionally, sexual relationship between man and women is alegal and religious commitment. However, due to increased advocacyfor the recognition of same sex relationship and marriage, there isan increased tolerance towards diversity in sexual orientation. Oneof the basic dilemmas in the same sex relationships and marriages hasbeen why some individuals have homosexual and bisexual preferences.

The book “Gay,Straight and the Reasons Why: ” isa scientific explanation of the different sexual orientation amongmen and women in the modern society. Dr. LeVay provides detainedfindings of numerous scientific studies in the last two decades inthe factors that influence sexual orientation in human. The authorhad done studies on the role of hypothalamus and its role in thedevelopment of humans. The book attempts to bring together thefindings of different studies in order to develop a coherent and allinclusive theory that explains differences in sexual orientation.According to LeVay, psychologists and sociologists make a mistake inconsidering the sexual behaviors of individuals in determining thesexual orientation. In his assessment, the sexual feeling is thebasic consideration, although the sexual behavior can be consideredin special cases. Although a number of factors have been proposed toinfluence sexual orientation, LeVay considers inheritedcharacteristics from parents as the main factors that influencesexual differentiation in the human brain and consequently sexualorientation. In addition to the common sex hormones and geneticmakeup, the womb environment before birth and condition of the motherduring pregnancy, for example stress and depression, can have aninfluence on sexual differentiation. However, the geneticcharacteristics and hormonal influence on sexual feeling andbehaviors does not stop at birth but continues throughout theindividual’s life.

According to LeVay findings,there are numerous feminine genes that play a role in the developmentof sexuality in men. Similarly, male genes play a role in humansexuality. A limitation in the number of genes inherited from parentsfor example may influence male sexuality by making them lessaggressive or to have more empathy and therefore more attractive towomen. LeVay argues that this genetic characteristic gives some menreproductive advantage. Less feminine hormones may make a man moreaggressive and cold, thus less attractive to women. On the otherhand, a man who inherits excessive feminine hormones tends to havehomosexual characteristics. Although LeVay looks at some of theFreundian theories that explain the development of homosexualcharacteristics in gays, he is skeptical about the theories.According to Freudian theories of sexual orientations, theenvironment influences the individual’s sexual preferences andfeelings. For example, gay men may have had a hostile and distancerelationship with their fathers while being closer to their mothers.LeVay refers to different studies that proof that the Freudiantheories “reverse the direction of causation”.For example he refers to cross cultural studies such as GilbertHerdt’s study on homosexuals in Sambia and British schools to arguethat behaviorist’s theories of sexual orientation are inaccurate.

However, it is important tonote that reverse the direction of LeVayspends a considerable effort to validate his study of thehypothalamus while writing the book. While some people have arguedthat differences in the structures of gay men brains compared tostraight men is as a result of infections such as AIDS common amonghomosexuals, LeVay studies had a different finding. In his studies,he established that the pathological differences between gay andstraight men brain was obvious and not related to infections as ithas been postulated in the late 1980s and early 1990s. For example,in a study that he was able to replicate, he established that in gaymen who died of AIDS and other causes, the INAH3 was the same sizebut different from that of straight men. LeVay refers to anotherstudy by Willian Byne, a neuroscientists who established that thesize of INAH3 in gay men was different compared to that of straightmen.

The journal article “sexualdifferences of the human brain: relevance for gender identity,transsexualism and sexual orientation” by Swaab provide credibleevidence on the critical role of the brain structure in thedevelopment of sexual orientation. Although there are more evidencesthat have been confirmed in more recent studies, Swaab (2004) looksat the scientific evidences that disqualifies social factors in thedevelopment of sexual differentiation. The article providesinteresting findings, for example, the study of the role of sexualdifferentiation in humans using rodents as examples is not a goodmodel. This is due to the differences in the conversion of sexhormones in rodents and humans. The articles look at role ofinherited factors in the development of sexual preferences and genderidentities and the impacts of genes and gene mutation. According toSwaab (2004), genetics factors and there influence on sexualpreferences “appear from studies in families, twins and throughmolecular genetics”. Despite molecular genetic studies beingrelatively new, “geneticlinkage between microsatellite markers on the X chromosome, i.e.Xq28, was detected for the gay male families, but not for the lesbianfamilies”.

Swaab(2004) also identifies several sex hormones that have an influence onthe development of sexual orientation. For example, in young womenwith congenital adrenal hyperplasia, sex hormones were found to plantan important role in the development of sexual preferences. Studieshave established that “there is a DES, a compound related toestrogens that increases the occurrence of bi- or homosexuality ingirls whose mothers received DES during pregnancy”. Additionally,the immune response that has been observed in mother with successiveboy fetuses can explain the homosexual tendencies in individuals withelder brothers. The article disqualifies social factors includingmaternal stress during pregnancies as factors that influence sexualorientation. There are several studies that have established thatfact that majority of children brought up by homosexual or bisexualparents have heterosexual tendencies. These studies support thepostulate that the environment has no influence on the development ofsexual orientations.

There are numerous studiesthat have been done in the recent past to identify the most importantfactors in the development of sexual orientation. Despite this,scientists concur with the argument that a particular factor that isresponsible for the development of sexual orientation has not beenidentified. Sexual orientation observed is therefore considered to beas a result of several factors. Also, although there may be differenthormones involved in the development of sexual orientation in men andwomen, the process is considered to be relatively the same.Scientists have identified genetic materials, activity of particularsex hormones, dynamics involved in the development and social factorsthat determine whether an individual will develop homosexual orheterosexual behaviors. In the past, it was postulated thathomosexuality was as a result of problems in the psychologicaldevelopment during childhood. Some scholars maintain that faultypsychological development resulting from troubled childhood such aschild abuse and lack of role model or unstable relationships mayinfluence the development of homosexuality. This is despite thesepostulations being dismissed by cross sectional and longitudinalstudies.

It is important to note that there is limited research on thedifference in sexual development in women and men. However, recentstudies have identified some differences in the development of sexualorientation and preferences in men and women. The differences aremainly based on the different factors that are considered to ignitesexual desires and arouse men and women. Studies have establishedthat both homosexual and heterosexual women are sexually aroused byboth male and female and thus exhibit bisexual patterns. However,this trend has not been observed in men. Behavioral scientists haveconcluded that these findings may be a clear representation of thesignificant variations in the development of male and female brainsand its influence on the development of sexual orientation.

In animals, although diversity in sexual orientation is limited,there are several cases of homosexual tendencies that have beenobserved in some species. There are several ways through whichanimals express their sexual preferences which could be through“sexualactivity, courtship,affection,pairbonding, and parentingamong same-sex animal pairs”. Cases of homosexuality or bisexualrelationships in animals are limited and sex is generally forreproduction purposes. The existence of homosexuality among animalshas been one of the justifications of homosexuality in human. This isbased on the argument that in the same way some animals are naturallyhomosexual or bisexual, sexual orientation in male are natural, somepeople are born gay and should not be condemned (LeVay).

Evolutionally scientists have made numerous attempts to provideevidence that evolution has a role to play in the development ofsexual orientation. They argue that the brain of an individual iscomposed of modules which are designed to perform specific function.These modules have enabled humans to react to environmentalchallenges which have facilitated their survival. Thus, human adoptsadaptive traits which enable them to produce more successfully. Thisexplains why majority of people develop heterosexual preferences,which has been persistent throughout the history of human kind, sinceit facilitates reproduction. However, the evolutionally theories ofsexual orientation have been criticized due to the fact that they areunable to explain the developed of homosexual preferences, which doesnot promote human race survival through reproduction. In defense,they have argued that the science of sexual orientation is toocomplex to be explained using one model.


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