0:00:00.287,0:00:04.067 There's a lot of misinformation out there[br]about what it means to be transgender, 0:00:04.067,0:00:07.021 but recently, scientists[br]have begun to look more closely 0:00:07.021,0:00:11.021 into the neurology,[br]physiology and psychology behind it. 0:00:11.021,0:00:13.894 So today, we're going to break down[br]what science does know 0:00:13.894,0:00:16.054 in a respectful and educational way. 0:00:16.054,0:00:19.445 Hey, guys, I'm Gigi Gorgeous[br]and today I'm here with AsapSCIENCE 0:00:19.445,0:00:22.345 to break down[br]the science of being transgender. 0:00:22.345,0:00:24.350 Before we get too deep into it, 0:00:24.350,0:00:27.871 we have to look at your genetic sex[br]or the chromosomes you have. 0:00:27.871,0:00:30.481 These were determined[br]right at fertilization, 0:00:30.481,0:00:34.776 when the sperm cell from your father,[br]which carries an X or a Y chromosome, 0:00:34.776,0:00:38.056 fused with the egg from your mother,[br]which carries an X chromosome. 0:00:38.056,0:00:41.309 But until six or seven weeks[br]after fertilization, 0:00:41.309,0:00:45.622 both XY and XX embyos[br]have identical gonads. 0:00:45.622,0:00:48.551 Around seven weeks,[br]the male sex organs start to develop 0:00:48.551,0:00:52.371 because of a gene[br]on the Y chromosome called SRY. 0:00:52.371,0:00:54.633 It causes cells to become more specialized 0:00:54.633,0:00:56.657 and these cells create testosterone, 0:00:56.657,0:01:00.657 which in turn triggers the development[br]of structures like the penis and scrotum, 0:01:00.657,0:01:04.503 while other cells block female development[br]by degenerating the female ducts. 0:01:04.503,0:01:06.581 However, in female development, 0:01:06.581,0:01:09.991 because there is no Y chromosome[br]with the SRY gene, 0:01:09.991,0:01:13.249 these ducts stay intact[br]and become the uterus, cervix, 0:01:13.249,0:01:15.029 upper vagina and the oviduct, 0:01:15.029,0:01:18.932 with the help of estrogen and chemicals[br]secreted by the early kidney. 0:01:18.932,0:01:21.314 But it's not always that simple. 0:01:21.314,0:01:25.028 There are sometimes[br]even rare combinations like XXY, 0:01:25.028,0:01:28.185 XXX, XXYY, etcetera, 0:01:28.185,0:01:30.465 and even people with XX chromosomes 0:01:30.465,0:01:32.938 that develop[br]male genitals and characteristics, 0:01:32.938,0:01:35.498 due to a piece of the Y chromosome[br]breaking off 0:01:35.498,0:01:39.498 and switching places to an X chromosome. 9:59:59.000,9:59:59.000 But sexual differentiation in the brain 9:59:59.000,9:59:59.000 actually happens much later[br]than gonadal differentiation. 9:59:59.000,9:59:59.000 And yes, although controversial,[br]male and female brains 9:59:59.000,9:59:59.000 have structural and functional differences[br]between each other. 9:59:59.000,9:59:59.000 Studies have found that males[br]generally have a larger cerebrum, 9:59:59.000,9:59:59.000 cerebellum, and hippocampus, 9:59:59.000,9:59:59.000 while females[br]have higher-density left frontal lobes 9:59:59.000,9:59:59.000 and larger volumes[br]in the right frontal lobes. 9:59:59.000,9:59:59.000 So what exactly do we see 9:59:59.000,9:59:59.000 when we look at the brain[br]of a transgender person? 9:59:59.000,9:59:59.000 Several studies[br]have shown that transgender brains 9:59:59.000,9:59:59.000 are both structurally[br]and functionally more similar 9:59:59.000,9:59:59.000 to their experienced gender identity[br]than their biological sex. 9:59:59.000,9:59:59.000 One study found that trans women who,[br]despite being assigned male at birth, 9:59:59.000,9:59:59.000 had a smaller female-sized structure[br]in the hypothalamus. 9:59:59.000,9:59:59.000 MRI scans also show[br]the brain structures of trans people 9:59:59.000,9:59:59.000 to be more similar in thickness 9:59:59.000,9:59:59.000 to their experienced gender[br]and not their sex. 9:59:59.000,9:59:59.000 Finally, the pheromone androstadienone 9:59:59.000,9:59:59.000 causes different hypothalamic responses[br]in male and female brains. 9:59:59.000,9:59:59.000 And when individuals with gender dysphoria[br]were exposed to it, 9:59:59.000,9:59:59.000 the hypothalamic response 9:59:59.000,9:59:59.000 matched their perceived gender[br]rather than their sex. 9:59:59.000,9:59:59.000 These studies help to highlight 9:59:59.000,9:59:59.000 how masculinization[br]or feminization of the gonads 9:59:59.000,9:59:59.000 is not always the same as the brain 9:59:59.000,9:59:59.000 and that there's a difference[br]between your sex or your anatomy 9:59:59.000,9:59:59.000 and your gender[br]or how we perceive our own bodies. 9:59:59.000,9:59:59.000 There also seems to be a genetic component[br]to transgender identity. 9:59:59.000,9:59:59.000 Looking at family histories, 9:59:59.000,9:59:59.000 gender identity incongruence[br]seems to run in the family, 9:59:59.000,9:59:59.000 meaning they may be inherited. 9:59:59.000,9:59:59.000 The CYP17 gene, which controls[br]the body's level of sex hormones, 9:59:59.000,9:59:59.000 has a changed 9:59:59.000,9:59:59.000 that is expressed frequently in trans men. 9:59:59.000,9:59:59.000 Although more research could be done, 9:59:59.000,9:59:59.000 scientists are currently looking 9:59:59.000,9:59:59.000 at over three million DNA markers[br]for transgender identity 9:59:59.000,9:59:59.000 to investigate any genetic link for being trans. 9:59:59.000,9:59:59.000 Even though scientific studies validate[br]the experience of transgender people, 9:59:59.000,9:59:59.000 they're still suffering[br]from more depression and anxiety 9:59:59.000,9:59:59.000 than the general public. 9:59:59.000,9:59:59.000 The risk of suicide[br]is more prominent in transgender people 9:59:59.000,9:59:59.000 who have been rejected by their family, 9:59:59.000,9:59:59.000 discriminated in the workplace[br]or in health care. 9:59:59.000,9:59:59.000 Suicide risks seem to decrease[br]after gender transitioning, 9:59:59.000,9:59:59.000 suggesting that gender dysphoria 9:59:59.000,9:59:59.000 can cause an extreme amount[br]of emotional pain, 9:59:59.000,9:59:59.000 even to the point of suicide. 9:59:59.000,9:59:59.000 If you, a family member or a friend[br]is suffering from gender dysphoria, 9:59:59.000,9:59:59.000 there are a few links in the description[br]for more information. 9:59:59.000,9:59:59.000 Thank you so much, Gigi,[br]for being part of this video. 9:59:59.000,9:59:59.000 It means so much, and we're happy[br]that you were here to do this with us. 9:59:59.000,9:59:59.000 Thank you guys[br]for using your channel, your platform, 9:59:59.000,9:59:59.000 validating transgender experiences[br]with science, 9:59:59.000,9:59:59.000 which just brings us closer to equality. 9:59:59.000,9:59:59.000 Absolutely. If you guys[br]want to check out Gigi's channel, 9:59:59.000,9:59:59.000 we'll put links in the description[br]or on the screen somewhere. 9:59:59.000,9:59:59.000 Otherwise, you can subscribe[br]for more science here, 9:59:59.000,9:59:59.000 every week, and we'll see you next time. 9:59:59.000,9:59:59.000 Peace!