The biology of being gay

THE NOSE KNOWS

In order to test the biological reactions of different sects of sex, scientists played around with smells. Instead of waving sweaty shirts or gym socks around, they came up with two derivatives to use: one was testosterone derivative, the other an estrogen compound. When the gay men in the study took a hearty whiff of “T,” their hypothalamus glands lit up like Christmas trees. Ditto the straight women. Accordingly, lesbians and straight men were into the “E.” Turns out, there’s a biological call-and-answer beyond our control which is further proof that humans really don’t get a conscious choice in the matter of what’s hot and what’s not.

WOMB FOR TWO

In general, you have about a five percent chance of being born gay. But if you’re one half of a pair of fraternal twins (sharing the womb but only half your DNA — the same amount as any other biological sibling), you’ve got about a 25 percent chance of being faaaabulous! If you and your womb-buddy were born identical twins (sharing all of your DNA), your chances skyrocket to around 52 percent! Those numbers suggest to researchers that “Born This Way” isn’t just a Gaga song that shares 36 percent of its melodic composition with Madonna’s
“Express Yourself.”

EPIC GENETICS

So if identical twins have identical genes, why do some twins have differing sexualities? That’s an exciting question that researchers feel they’ve narrowed down to epigenetics. Our epigenomes activate (or deactivate) the our genes by attaching to DNA to switch genes “on” or “off” — using the gene for hair growth, for example, they’ll attach the right amount of methyl-based compounds to either grow our mane to glory or pull the brakes on Operation Wig. Some scientists theorize that all of us have the capability for same-sex attraction, but only some of us have the enzymatic cocktail to kickstart the (as-yet-unidentified) “gay gene” by switching it on. In the nature versus nurture debate, epigenetics are the biological link that bridges the two concepts.

 GREAT MINDS THINK ALIKE

Lesbians and straight men have similarities in their brain shapes, and gay men and straight women have similar-looking brain features as well. Lesbians and hetero-dudes tend to have asymmetrical brains that are larger on the right side, while gay men and hetero-chicks tend to have more symmetrical brains. The two sets of pairs also share similar connectivity in their amygdalas, the part of the brain that controls our “fight or flight” response and our emotional learning. While the study said nothing about the way these patterns inform our sexuality, it certainly provides some food for (genetically-biased) thought.