Gender and Sexuality in Humans

According to research, gender and sexuality spectrums in humans is influenced by our complex biological make up—and some other aspects too!

Have a read of some of the cool things researchers have found over the years.

1. Several studies have shown that the brains of gay cis males are more like straight cis female brains, whilst the brains of gay cis females are more like straight cis male brains. The differences observed were mostly in regards to sizes of various regions that differ between cis men and cis women, like the hemisphere proportions, the suprachiasmatic nucleus ( a small region of the brain that helps control the body's rhythms), and the third interstitial nucleus of the anterior hypothalamus (a region that influences maternal and sexual instincts, and also sexual development).

2. Studies have shown that some structures of trans male brains are similar to those of cis males, and some structures of trans female brains are similar to those of cis females. The aforementioned structure is called the bed nucleus of the stria terminalis (BSTc) and is known for governing sex and anxiety responses. Other correlations of this type have been seen to occur in the brain's cortex, too, which is said to influence gender. 

3. Studies have shown that trans females are more likely to have a different version of an androgen (associated with maintaining male characteristics) receptor than cis males. Trans males have something similar, but with a variation that affects the sex hormones pregnenolone and progesterone. Trans males have this variation more frequently than cis females. 

4. Cis men and cis women have different white matter structures in the brain. A study in 2010 found that trans men, who were not undergoing hormone treatment, had a white matter structure that was more like that of cis men then cis women. 

5. Humans have two proposed pheromones, namely "AND" (present in cis male sweat), and EST ( present in the urine of pregnant women). Studies have shown that heterosexual men and homosexual women have similar brain responses when exposed to these pheromones. Likewise, heterosexual women and homosexual men have similar brain responses.