“Is it or is it not,” appears to be the main question on the mind of many regarding homosexuality. Whether the chromosomes we are born with or our upbringing pre-determines our sexual orientation. Scientific curiosity, salvation from God, or salvation from those who would create a new Sodom and Gomorrah are reasons many seek the answer. Many, whether in the scientific community or not, have already made up their minds. Whichever way these persons argue the truth lays, however, there are others, just as equally convinced, that the opposite is true. At this time, however, there is more strength to the argument that homosexuality is based on nature not nurture.

One of the strongest supports for the view that genetics accounts for whether someone is gay or not comes from studies of persons who were born male, but raised as women (Abrams). These “boys” were raised as girls due to having birth defects or accidents which prevented them from being full boys and it was deemed better to raise them as girls (Abrams). These boys/girls were socialized entirely as girls and encouraged to be feminine (Abrams). Yet, William Reiner, a psychiatrist at the University of Oklahoma Health Sciences Center, who studied a group of such “women” in adulthood, discovered that they still ended up being attracted to women (Abrams). “If societal nudging was what made men gay, at least one of these boys should have grown up to be attracted to men. There is no documented case of that happening,” (Abrams). This, more than anything, points to a genetic basis for homosexuality.

The mother is seen to hold the “key” to whether or not a fetus will be born gay. Ray Blanchard, a psychiatric researcher at the University of Toronto, found in 1996 that men with older brothers were more likely to be gay than those who were first born or only children (Abrams). Blanchard’s study showed that for every older brother a man has his odds of being gay go up by 33% (Abrams). For example, if the theoretical possibility that a couple's first son will be gay is 2%, Blanchard says, the probability their fifth son will be gay increases to 6% (Abrams). However, he continues, if “some poor woman” has 14 sons, the 15th would have a 50% chance of being gay (Abrams). The following graph visually illustrates this finding:

Other studies have quashed the notion that regardless of the womb, being gay for a man with more older brothers is due to the environment the boys grown up in. Not only have Blanchard’s results been replicated some 20 times, but psychologist Tony Bogaert of Brock University in Ontario found that when he looked at gay men who were raised in non-biological families, those who turned out to be gay could be directly tied to the womb they were born from, not the environment in which they were raised (Abrams). As Bogaert said, “’It's not the brother you lived with; it's ... sharing the same morn,’” (Abrams).

Also supporting the conclusion that children are born gay are studies which have found consistent body differences between homosexual and heterosexual persons. In 1991 neuroscientist Simon LeVay found structural differences between the brains of gay and heterosexual men (Mubarak). LeVay found there was a difference in size between the hypothalamus, the gland believed to affect sexual behavior, of gay versus heterosexual men (Mubarak). LeVay postulates that “gay men's brains develop differently than straight men's because they are exposed to higher levels of testosterone during pregnancy,” and states there is “growing evidence to support the idea that biological and developmental factors before birth exert a strong influence on sexual orientation,” (Mubarak).

Research finding other similar physical differences between homosexuals and heterosexuals provides mounting evidence that genetic and/or hormonal factors are responsible for sexual orientation. Studies from England’s University of Liverpool showed that gay men and women were more likely to be left-handed and that lesbians’ hand patterns resemble those of men more than that of straight women (Mubarak). A scientist at the University of Texas at Austin, Dennis McFadden, found that lesbians' auditory systems seem to develop somewhere between what is typical for heterosexual men and women (Mubarak). Marc Breedlove, a psychologist at the UC, Berkeley, found a direct correlation between the lengths of some fingers of the hand and gayness (Mubarak). Also, much to the frustration of “macho” straight men, gay men tend to be more well endowed than straight men (Mubarak). All of these findings point to factors which are the result of differences in prenatal development (Mubarak). Breedlove attributed his finger-length findings to differences in testosterone levels gay and straight men experience in the womb (Mubarak) LeVay supports that finding, adding that there is a “growing body of research to support the theory that different hormone levels can cause the brain to differentiate one way or the other--to be straight or gay," (Mubarak).

The conclusion that hormonal differences during development make a person gay is also supported through the discovery of gay animals. For example, it has been found that 8% of rams are gay (Schneider). The existence of these animals strongly argues against the idea that nurture can turn a “straight” person gay because nurture is not a factor in the animal world. More and more scientists have come to the conclusion that genetics is the key to whether someone will be gay or not (Schneider). Dean Hamer, a molecular biologist at the National Institutes of Health, studied the family histories of 114 gay men in 1993 and discovered that many of their male relatives on the mother's side of the family were also gay (Schneider). Because men inherit an X chromosome from their mothers, Hamer’s study strongly suggested a genetic link between the X chromosome and homosexuality (Schneider). Studies by J. Michael Bailey, a psychology professor at Northwestern University, and Richard Pillard, a psychiatrist at Boston University School of Medicine showed that a person with a gay identical twin is at least 10 times more likely to be gay; a man with a fraternal gay brother is three to seven times more likely to also be gay; and a woman with a lesbian sister is four to eight times more likely to also be lesbian (Schneider). As Pillard says, “All this shows that sexual orientation is largely genetic," (Schneider). Hamer himself, argues that while no specific gene or chromosome pairing has yet been found, his research in 1993, in which he scrutinized the DNA of 40 pairs of gay brothers, showed that 33 pairs of brothers shared a specific region on a portion of the X chromosome (Mubarak).

Many in the scientific community have discounted the studies and findings of Hamer, due to the low number of subjects he used, however, this may now be changing (Abrams). Geneticist Sven Bocklandt at UCLA has been trying to find the specific “gay” gene Hamer’s work suggested, but he has not yet (Abrams). A much larger study than that of Hamer’s is being undertaken by Alan Sanders, an associate professor of psychiatry at Northwestern, who will look at the whole genome of about 1,000 gay brothers to see if he can find a “specific gene” that makes a person gay (Abrams). Even if one single “gay” gene is not found, there may be a series of genes or points at which the genetic code, if turned off (methylation), may make a person gay (Abrams). Bocklandt is conducting work with twin pairs of men to see if he can identity the “switch” that makes a person gay through mehtylation (Abrams).

The work of these scientists, however, is simply not accepted by many. Some of these also argue that genetics alone, although a large part of the reason people are gay, is not the only factor. LeVay himself says he cannot “honestly ... be sure how to interpret the differences” he “found in brain structure," and says he would not “rule out that life experiences can play a role," (Mubarak). However, these scientists do suggest that while not the only factor, genetics represents 50% to 70% of the reason people are gay (Mubarak). Others, however, say that if being “gay” is based on genetics, then, because gay men have not until recently been able to procreate, the “gay gene” should have been lost long ago (Abrams). But, scientists also indicate that gay boys receive 50% of their genetic code from their mothers, and women who come from families where there are many gay men, tend to have more children than women from families who do not have gay men, which may account for the survival of the “gay gene,” and, in societies were being gay is an embarrassment, gay men are more likely to marry and procreate, simply to fit in (Abrams). Moreover, if environment were the dominant factor in turning a person gay, the work of Reiner would have discovered a case of a “faux woman” who was attracted to women, but no such “woman” has been found (Abrams).