“Heterosexuality is not normal, it’s just common.”
― Dorothy Parker
Why are some people gay?
Is homosexuality a choice?
Is being gay or lesbian genetic?
Read on to find out.
Homosexuality – sexual interest or attraction towards members of one’s own sex.
Ever since the earliest recorded times, there have always been people who engaged in what we now identify as “same-sex relationships”. The world’s earliest depictions of homosexuality date back to around 8000 B.C. and are found in the ancient San rock paintings of Zimbabwe, Africa. The acceptance and understanding towards these relationships have varied over time and culture, from it being approved, tolerated to viewing upon the practice as a sin and enforcing laws to repress it and to proscribing it under penalty of death.
The cause of homosexuality has been a topic of widespread public fascination and a subject of extensive research in recent years. While we are yet to pinpoint the exact reason behind it, scientists say that a combination of genetic, hormonal and societal factor determines a person’s sexual orientation.
Are there “Gay Genes”?
A study conducted in 1993 showed that genetic variations in a region on the X chromosome in men were linked to whether they were heterosexual or homosexual. In 1995, a region on chromosome 8 was identified. Both findings indicate that sexual orientation might be partly inheritable in men, although they did not home in on any specific genes on the chromosome.
In a breakthrough at North Shore University, Illinois, a team of researchers have, for the first time, identified two individual genes that may influence sexual orientation in males, both in the womb and during life. The team compared DNA from 1077 gay and 1231 straight men. They scanned the men’s entire genomes, looking for single-letter differences in their DNA sequences. The findings bring us a step closer to proving that homosexuality is rooted in genetic factors and is not a “choice” as many people claim.
What exactly did the study find?
One of the genes, called SLITRK6 which sits on chromosome 13, is active in a part of the brain called the diencephalon. Interestingly, this brain region contains the hypothalamus, which was identified in 1991 as differing in size between gay and straight men.
Another gene called the TSHR is found on chromosome 14 and is mainly active in the thyroid. It makes a type of receptor protein that recognises and binds to a hormone that stimulates the thyroid. In this way, the gene plays an important role in controlling thyroid function.
The fact that TSHR seems to be involved in sexual orientation fits with evidence that thyroid function seems to be linked to sexuality. For instance, TSHR function is disrupted in a condition called Grave’s disease, which is an autoimmune disorder that leads to overactivity of the thyroid gland (hyperthyroidism), accelerating metabolism and consequent weight-loss. Grave’s disease is more common in gay men than straight men, and some research suggests that gay men tend to be thinner – which might possibly be a result of thyroid overdrive.
Now you might wonder, “What about women who are gay? Are there “lesbian genes”?
Until now, relatively more research has been done on men and hence our understanding of homosexuality in women lags behind. Although, it’s considered that there are underlying genetic causes for that too.
Research on homosexuality still continues.
On a personal note,
“Being gay is not a “lifestyle choice”. It is part of a person’s identity. No matter what your sexual orientation, at the end of the day, we’re all just human.”
