The Complex Science Behind ‘Gaydar’
Guest post from Fintan Steele (he/him), ex-science researcher, ex-priest and monk, and current science writer and editor in Boulder County.
Note from OBC: We have asked Fintan to contribute monthly about LGBTQ+ and science topics.
Is “gaydar” real? Goodness knows a lot of science has been done around the phenomenon, although no fully satisfactory explanation for its physical basis has yet emerged. But the evidence strongly suggests there is something biological to it. And, like all complex human biological traits, what we call gaydar is probably the sum of the many different ways we perceive our world and each other.
In a way, our bodies are like a dense field of satellite dishes, each dish straining to pick out relevant signals from a whole bunch of existential noise coming at it. Every one of our senses (touch, sight, smell, etc.) begin with some kind of protein “receptor” attuned to pick up sound, odor, pressure, taste, sound or light, and turn it into useful information to help us navigate through the world. Though you don’t experience it directly, while you are reading this text a group of proteins in your retinas are grabbing photons of light and turning them into electrical activity that your brain interprets as “reading.” You’re unconsciously shifting in your chair as body parts complain of growing numb through their touch receptors. Maybe, like me, you’re ignoring the yowl of your cat for more food but responding to the washing machine’s end-of-cycle chirp (sound waves selectively being turned into decisions to respond or not). Hormones (various chemical messages sent from one part of the body to another) are being captured by receptors on specific cells, interpreted, and responded to (or not) by their recipients. Basically, we are being inundated at virtually every moment with external and internal signals of all kinds that our brains ultimately have to sift through and decide which are important and whether any response is required.
How is this related to gaydar? It is worth looking more closely at a few of the specific results of a study I mentioned in a previous blog entry, in which a group of scientists scanned the genomes of a half million people to look for genetic changes associated with sexual behavior and — to a lesser degree — identity. Their findings are certainly provocative, though not absolute. In particular, it suggests that genes that direct the making of proteins involved in olfaction (our sense of smell) and other genes that direct the making of proteins involved in sex hormone biology appear to be different between heterosexuals and LGBTQ+ individuals.
There is a long history of research that shows a strong relationship between scent detection and sexual and gender differences, including the observation of anatomical brain changes in response to sex pheromones between different sex and gender groupings. The genetic study confirms and builds on this earlier work. They also show that the differences are not just in the mechanical detection of the scent (e.g., how the signal hits the satellite dish), but also in how the brain processes and responds to the scent. Furthermore, some of the olfactory detection and the response to that scent is mediated by sex hormones, which themselves are subject to genetic changes. And it has been known for some time that vision and sound are tightly intertwined with sexual response. There is a lot of work yet to do, but one gets a glimpse of what might be the foundation of a network of interconnected changes that might be at least partially involved in so-called gaydar, as well as sexual identity and orientation.
Again, these genetic findings are suggestive but not proven. There are many caveats about the study’s selection of subjects, definitions of sexual behavior, gender self-identity, etc. Furthermore, this is an “association study,” i.e., it looks at large chunks of the entire genome that are associated with the trait in question (in this case sexual behavior), and what genes are located in those positively associated regions that might be relevant in understanding attraction and identity. But the findings do demonstrate pretty convincingly that there are many different small genetic contributions overall, a couple of which make some intuitive sense but need to be proven more thoroughly.
Finally and most importantly, as we’ve noted before, genetics alone doesn’t account for all sexual identity and preference differences: Our genomes are ultimately interpreted through the lens of the environment they are in. That includes everything that “happens” to us from the day we are conceived until the day we take our leave. Complex environments and complex genetics combined in time and space. So it should come as no surprise that there is a lot of variation, not just across sex-related attributes, but in pretty much any human trait. Not better or worse, just different. Perhaps that awareness is science’s most valuable contribution to human understanding.
Other posts by Fintan Steele:
Fear and Loathing: Unpacking Homophobia
Yet We Persist: LGBTQ+ and Evolution
