Biological And Environmental Causes Of Homosexuality Essay

According to the American Psychological Association (2013), science has shown that the causes of homosexuality are generally related to the biological and environmental factors. There are a wide range of environmental factors, such as sociological and psychological, and various genetic factors that contribute to homosexuality, and though researchers agree that it is caused between a relatively complex interchange between nature (biological) and nurture (environmental). Social and psychological models, such as theories and studies that explains parental and family dynamics as a factor to homosexuality, and biological models, such as theories and studies that explains sex-linkages, chromosomal patterns and genetics clearly explain such phenomenon.

These effects are detected by looking at pairs of twins and determining how often, when one of them is homosexual, then it explain that the other one is too. This rate is much higher in monozygotic, or identical, twins, who share all of their DNA sequence, having thirty to fifty percent in rate, rather than in dizygotic, or fraternal, twins, who only share only half of their DNA, where the rate is ten to twenty percent. If we assume that the environments of pairs of mono- or dizygotic twins are more or less equally similar, then we can arrive into a conclusion that the increased similarity in sexual orientation in pairs of monozygotic twins is due to their increased genetic similarity. These data, although not yet published, were presented by Dr. Michael Bailey at the recent American Association for the Advancement of Science meeting last 12th of February, and was widely reported on. They confirmed and extended findings from multiple previous twin studies across several different countries, which have all found fairly similar results. Altogether, the conclusion that sexual orientation is partly heritable was already firmly made. The reaction to news of this recent study reveals a concrete idea that homosexuality really arises due to genetic differences. Finding that a

The most powerful evidence--or if not, the most concrete evidence was found to be identifying which genes influenced it. There has been a widely reported finding in the early 1990’s, a discovery that was a breakthrough to determining the cause of homosexuality: the discovery of what was termed as the gay gene. The gay gene was discovered by Hamer and his colleagues, and the finding was based on a study that took in those families in which at least two brothers who were identified as a homosexual. There was a certain number of people had maternal relatives who were also identified as homosexual, implicating that in them, homosexuality was handed on through the mother rather than the father. In their discussion, the authors sought for the responsible gene in the X chromosomes of the brothers and found a homologous linkage of genes at a particular location on the chromosomes of the thirty-three pairs of brothers, out of the forty pairs of brothers, an affiliation very unlikely to be due or only a causation to chance. It was compared to the fact that females have two X chromosomes, whereas, compared to men, they only have one X and one Y chromosome. Consequently, genetic transmission should only occur through mothers with their X chromosomes. According to the authors, it explained that the genetic transmission should only come from the mother and that the chromosomal abnormality