No such thing as a singular "gay gene"

by Drew Kyla Baysa (Polyplex)

Each gene carries a piece of specific information that carries an individual’s traits. With an estimation of 20,000-25,000 genes in the human body, we would be clueless as to what gene carries a specific trait. Careful experimental design and appropriate genetic models are critical requirements for genetic analysis of behavioral differences among humans. The teasing part of genetic and environmental influences as factors for determining behavior became an ideal part of genetic analysis. When things are taken independently, genetics alone partly has something to do with same-sex behavior according to twin and family studies in the past.

With the help of close consultations with advocacy and outreach groups, and with the brilliance of science, an international group of researchers was able to provide better evidence that pins same-sex sexual behavior. A large scale GWAS (genome-wide association study) revealed five genomic variants that are associated with same-sex behavior while also establishing that there is no marker that would show how a person will behave sexually. From a 1993 study linking homosexuality to a specific region of the X chromosome, the study “Large-scale GWAS reveals insights into the genetic architecture of same-sex sexual behavior” sets the idea of Dean Harmer’s popular idea of “gay gene”.

Data were gathered from a total of 492,678 genotyped individuals who provided self reported-information about having to have sex with a same-sex partner from interviews and surveys including questions about sexual identity, sexual experience, sexual attraction, etc. The primary phenotype examined was whether a person had sex with someone of the same sex and from then, the team analyzed other phenotypes including the proportion of same-sex and opposite-sex partners which is significant for it shows support for the evidence that there is no single specific single gay gene but a lot of genomic variants with individually small effects contributing to individual differences in the tendency of same-sex sexual behavior.

The team notes that the five genetic variants together account for less than one percent of the variation. And only 8-25% of variation in same-sex behavior was the scope of all genetic variants tested. These numbers are describing the population itself and not individuals, showing the variability in the population that we see in genetics and connecting it to the variability we see in same-sex sexual behavior.

A genetic basis proves that gender is not a choice. However, this study is not credible enough to prove otherwise. Despite the limitations of the study such as lack of diversity and difference in culture, it did not disappoint the fact that science can help us learn more about ourselves, and to answer more questions about our behavior, which is the primary focus of the paper, and not about identity or orientation.