---
date: "2020-01-26T20:41:55.827Z"
lang: "tw"
title: "性別不一致的成因是什麼"
linkTitle: "性別不安的成因"
description: "是荷爾蒙，寶貝。"
preBody: '_disclaimer'
classes:
  - gdb
tweets:
  - https://twitter.com/LisaTMullin/status/1224039568971710464
  - https://twitter.com/LisaTMullin/status/1224040716365524993
  - https://twitter.com/LisaTMullin/status/1224041800513380352
  - https://twitter.com/LisaTMullin/status/1224041800513380352
  - https://twitter.com/LisaTMullin/status/1224042620164296705
  - https://twitter.com/LisaTMullin/status/1224043995413639168
  - https://twitter.com/LisaTMullin/status/1224044949160611840
siblings:
  prev: /tw/treatment
  prevCaption: 治療性別不安
  next: /tw/chromosomes
  nextCaption: 但是... 但是... 染色體！
---

<!-- # What is the Cause of Gender Incongruence? -->
# 性別不一致的成因是什麼？

<!-- To put it bluntly, we don't know (at least not firmly). Science and modern psychology has proven that it is **not** caused by nurture; no one *becomes* transgender, gender identity is congenital, solidifying before we even exit the womb. It also appears to sometimes be hereditary; transgender parents have a higher likelihood of having transgender children, and many times they realize this in reverse. The child comes out to the parent, and that helps the parent realize they can come out as well. -->
坦率地說，我們不知道（至少不確定）。科學和現代心理學已經證明，它 **不是** 由後天造成的；沒有人會 *變成* 跨性別者，性別認同是先天的，在我們離開子宮之前就已經確定了。它似乎有時也是遺傳的；跨性別父母更有可能擁有跨性別孩子，而且很多時候他們是反過來意識到這一點的。孩子向父母出櫃，這幫助父母意識到他們也可以出櫃。

<!-- Here is the science that is believed to influence gender identity. This does not mean that it *defines* gender identity, nor does it fully encapsulate one's gender, as so many aspects of gender are cultural and social. None of this is prescriptive of a person's identity, none of it is cast in stone. -->
以下是被相信會影響性別認同的科學。這並不意味著它 *定義* 了性別認同，也不意味著它完全涵蓋了一個人的性別，因為性別的很多方面都是文化和社會的。這些都不是對一個人身份的規定，都不是一成不變的。

<!-- If you've seen Jurassic Park, you may remember this scene: -->
如果你看過《侏羅紀公園》，你可能會記得這個場景：

<!-- {!{
  {{import '~/img' images.jurassicpark
    className="card borderless center span34"
    alt="All vertebrate embryos are inherently female anyway. They just require an extra hormone given at the right developmental stage to make them male."
    caption="This isn't science fiction, although it is very simplified."
  }}
}!} -->
{!{
  {{import '~/img' images.jurassicpark
    className="card borderless center span34"
    alt="所有脊椎動物的胚胎本來都是雌性的。它們只需要在正確的發育階段給予額外的賀爾蒙，就能使它們變成雄性。"
    caption="這不是科幻小說，雖然它被簡化了。"
  }}
}!}

<!-- {!{
<div class="gutter flex flex-center print-span3">
  {{import '~/img' images.fetalgenitals
    className="card"
    caption="<a href=\"https://schoolbag.info/biology/concepts/188.html\">Source</a>"
    alt="Fetal development of internal sexual anatomy"
  }}
</div>
}!} -->
{!{
<div class="gutter flex flex-center print-span3">
  {{import '~/img' images.fetalgenitals
    className="card"
    caption="<a href=\"https://schoolbag.info/biology/concepts/188.html\">來源</a>"
    alt="胎兒內部性器官發育圖"
  }}
</div>
}!}

<!-- The gonads in human fetuses initially develop in a bi-potential state, meaning they can become either ovaries or testes. The SRY gene on the Y chromosome releases a protein called [testis-determining factor](https://en.wikipedia.org/wiki/Testis-determining_factor) (TDF). This protein then starts a chain reaction with SOX9 production (another protein), which causes the gonadal cells to form into the Sertoli and Leydig cells that make up the testes. If TDF is never produced or is interfered with, the gonad cells form into the Theca cells and follicles which comprise the ovaries. -->
人類胎兒的性腺最初是在雙向潛能狀態下發育的，這意味著它們可以發育成卵巢或睪丸。Y 染色體上的 SRY 基因會釋放一種叫做[睪丸決定因子](https://zh.wikipedia.org/wiki/SRY%E5%9F%BA%E5%9B%A0)（TDF）的蛋白質。然後，這種蛋白質會啟動與 SOX9 生成（另一種蛋白質）的連鎖反應，這會導致性腺細胞形成組成睪丸的塞爾托利氏(Sertoli)細胞和萊迪希(Leydig)細胞。如果 TDF 從未產生或受到干擾，性腺細胞就會形成組成卵巢的膜細胞和濾泡。

<!-- Once formed, the testes then begin producing a testosterone surge which typically starts in the eighth week of gestation and continues until the 24th week. This surge, [combined with another hormone from the placenta](https://www.sciencedaily.com/releases/2019/02/190214153053.htm), is responsible for the development of the penis and scrotum. Genitalia formation starts around week nine and becomes identifiable by the 11th week. If the surge does not occur, or the body does not respond to it (such as in the case of androgen insensitivity syndrome) then the genitalia form into the vulva, vagina, and uterus instead. -->
一旦形成，睪丸就會開始產生睪固酮激增，通常從妊娠第八週開始，持續到第 24 週。這種激增[與來自胎盤的另一種激素相結合](https://www.sciencedaily.com/releases/2019/02/190214153053.htm)（英文），是陰莖和陰囊發育的原因。生殖器形成大約在第九週開始，到第 11 週就可以辨認出來。如果沒有出現這種激增，或者身體對它沒有反應（例如在雄激素不敏感症候群的情況下），那麼生殖器就會形成外陰、陰道和子宮。

<!-- If there is an interference in this process then you can end up with the wrong bits, and this is the result of many intersex conditions. Oftentimes this is a partial development, where the external genitalia only partially form but functional gonads still exist. Sometimes the child comes out with fully functional male or female genitalia, but mismatched gonads. Sometimes the TDF protein fails to release and the fetus grows completely functional female reproductive organs, despite the presence of a Y chromosome. -->
如果這個過程受到干擾，那麼你最終可能會得到錯誤的部位，這就是許多雙性人情況的結果。通常情況下，這是一種部分發育，外部生殖器只部分形成，但功能性性腺仍然存在。有時，孩子出生時具有功能齊全的男性或女性生殖器，但性腺不匹配。有時，儘管存在 Y 染色體，但 TDF 蛋白質未能釋放，胎兒長出了功能齊全的女性生殖器官。

<!-- This is known as Swyer syndrome, and an unknown number of women may have this condition. In 2015 [an XY woman with Swyer syndrome who was born without ovaries](https://www.independent.co.uk/news/science/mostly-male-woman-gives-birth-to-twins-in-medical-miracle-10033528.html) successfully carried and gave birth to a child via IVF. Usually, Swyer syndrome results in completely non-functional ovaries, but [in 2008 a woman was found with Swyer syndrome](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190741/) who had gone through puberty, menstruated normally, and had two unassisted pregnancies. Her condition went undiscovered until her daughter was found to also have it. -->
這就是所謂的斯威爾症候群(Swyer syndrome)，而且不知道有多少女性可能患有這種疾病。2015 年，[一位患有斯威爾症候群且出生時沒有卵巢的 XY 女性](https://www.independent.co.uk/news/science/mostly-male-woman-gives-birth-to-twins-in-medical-miracle-10033528.html)（英文）透過試管嬰兒成功懷孕並生下了一個孩子。通常斯威爾症候群會導致卵巢完全無功能，但在[2008 年，一位患有斯威爾症候群的女性](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2190741/)（英文）經歷了青春期、正常月經，並且有兩次自然受孕。直到她的女兒也被發現患有這種疾病，她的病情才被發現。

<!-- The fact is, the vast majority of the population has never been tested for genetic karyotype, so we don’t know how common these cases actually are. Where does this come into effect for gender identity? Well, the exact same process that causes the external genitals to differentiate also occurs for the brain. -->
事實上，絕大多數人都沒有接受過基因核型檢測，所以我們不知道這些病例實際上有多普遍。這對性別認同有什麼影響呢？嗯，導致外生殖器分化的過程也發生在大腦中。

<!-- {!{
<div class="gutter">
  <strong style="display: block;text-align: center;">And it gets even weirder!</strong>
  {{import '~/tweet' ids=[
    '1224039568971710464'
    '1224040716365524993'
    '1224041800513380352'
    '1224042620164296705'
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    '1224044949160611840'
  ] tweets=meta.tweets className="oneblock hide-reply" }}
</div>
}!} -->
{!{
<div class="gutter">
  <strong style="display: block;text-align: center;">而且他更奇怪!</strong>
  {{import '~/tweet' ids=[
    '1224039568971710464'
    '1224040716365524993'
    '1224041800513380352'
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    '1224044949160611840'
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</div>
}!}

<!-- #### Brain Split -->
#### 大腦分裂

<!-- The prenatal brain doesn't really start to develop until between week 12 and 24. The cerebral cortex, the thin outer layer of the brain that contains most of what we think of as consciousness, grows substantially during those periods of time. Prior to that, the structure present is more like a scaffolding — the basic parts of the nervous system necessary for bodily function. The primary sulci (the wrinkles in the cerebral cortex that allow for more surface area) [start to form at week 14](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989000/#Sec5title), well after the genitals have developed. -->
胎兒的大腦在第 12 到 24 週之間才真正開始發育。大腦皮層是大腦的薄薄的外層，包含了我們認為的大部分意識，在這段時間內會大量生長。在此之前，存在的結構更像是一個框架——身體機能所需的神經系統的基本組成部分。主要的腦溝（大腦皮層的皺褶，允許更大的表面積）[在第 14 週開始形成](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2989000/#Sec5title)（英文），遠在生殖器發育之後。

<!-- It [has been confirmed multiple times](https://www.the-scientist.com/features/are-the-brains-of-transgender-people-different-from-those-of-cisgender-people-30027) via MRI studies that there are small but significant differences between cis male and cis female brains — differences which align with the gender identities of trans people in the study. Note that **this does not mean that anyone with those differences will have that gender**; gender identity isn't that simple, but it provides evidence that there is a clear difference in masculine and feminine brains. [There is also evidence](https://www.pnas.org/content/112/50/15468) that brains can have mosaic combinations of these differences, which may be the case in non-binary people. -->
透過 MRI 研究[已經多次證實](https://www.the-scientist.com/features/are-the-brains-of-transgender-people-different-from-those-of-cisgender-people-30027)（英文），順性別男性和順性別女性的大腦之間存在微小但顯著的差異——這些差異與研究中跨性別者的性別認同相符。請注意，**這並不意味著任何有這些差異的人都會有那種性別**；性別認同沒有那麼簡單，但它提供了證據，表明男性和女性的大腦有明顯的差異。[也有證據](https://www.pnas.org/content/112/50/15468)（英文）表明，大腦可以有這些差異的鑲嵌組合，這可能是非二元性別者的情況。

<!-- A change in the testosterone levels in the fetus after the 11th week can directly impact the masculinization of the cerebral cortex, as well as changes in other parts of the brain structure. This has been examined [over and over again](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350266/) in studies of female-assigned children with CAH (congenital adrenal hyperplasia) and CAIS (complete androgen insensitivity syndrome). -->
在第 11 週之後，胎兒體內睪固酮水平的變化會直接影響大腦皮層的男性化，以及大腦結構其他部分的變化。在對患有 CAH（先天性腎上腺增生症）和 CAIS（完全雄激素不敏感症候群）的女性指定兒童的研究中，這一點已經被[反覆檢驗](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4350266/)（英文）。

<!-- <blockquote class="cite"><p>We found a significant relationship between fetal testosterone and sexually differentiated play behavior in both girls and boys.</p>&mdash; <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778233/">Fetal Testosterone Predicts Sexually Differentiated Childhood Behavior in Girls and in Boys</a></blockquote> -->
<blockquote class="cite"><p>我們發現，胎兒睪固酮與女孩和男孩的性別差異遊戲行為之間存在顯著的關係。</p>&mdash; <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2778233/">胎兒睪固酮預測女孩和男孩的性別差異童年行為</a>（英文）</blockquote>

<!-- An excess of testosterone in the mother’s body during the second trimester can (and does) cause masculinization of the brain in an externally female fetus, and an interference in testosterone production or uptake can (and does) cause feminization of the brain in an externally male fetus. This interference does not have to be external in origin, either. Any number of genetic traits can cause the brain to respond differently to testosterone. -->
在妊娠中期，母親體內過多的睪固酮會（而且確實會）導致外部為女性胎兒的大腦男性化，而睪固酮產生或吸收受到干擾會（而且確實會）導致外部為男性胎兒的大腦女性化。這種干擾也不一定是外源性的。任何數量的基因特徵都可能導致大腦對睪固酮的反應不同。

<!-- A fairly large study of transgender individuals released in 2018 [found several key genes](https://academic.oup.com/jcem/article/104/2/390/5104458) which were statistically more likely to be longer among trans women (longer as in having more repeated fragments). Individually these genes may not have an impact strong enough to cause a malfunction of masculinization, but collectively they absolutely could reduce the ability for the fetal brain to masculinize. These genes are all passed from parent to child, giving credence to a tendency for trans parents to have trans children. -->
2018 年發布的一項針對跨性別者的相當大規模的研究[發現了幾個關鍵基因](https://academic.oup.com/jcem/article/104/2/390/5104458)（英文），這些基因於統計學中在跨性別女性上更可能更長（更長是指有更多重複的片段）。單獨來看，這些基因的影響可能不足以導致男性化功能失調，但總的來說，它們絕對會降低胎兒大腦男性化的能力。這些基因都是從父母傳給孩子的，這也證明了跨性別父母更有可能擁有跨性別孩子的傾向。

<!-- #### Gender is Biological -->
#### 性別是生理的

<!-- Sadly, western society has actively prevented a deeper understanding of gender. Ancient civilizations understood it well, but colonialism wiped them off the map. 100 years ago, [scientists in Germany were actively studying](https://en.wikipedia.org/wiki/Institut_f%C3%BCr_Sexualwissenschaft) transgender medicine and made extraordinary advancements, until the Nazis burned it all in 1933. Conservative and fascist pressures in the modern day have hindered advancements in transgender healthcare whenever possible. -->
可悲的是，西方社會積極地阻礙了對性別的更深層次的理解。古代文明對此很了解，但殖民主義將它們從地圖上抹去了。100 年前，[德國的科學家正在積極地研究](https://en.wikipedia.org/wiki/Institut_f%C3%BCr_Sexualwissenschaft)（英文）跨性別醫學，並取得了非凡的進展，直到 1933 年納粹將所有這些都燒毀。現代社會中保守主義和法西斯主義的壓力盡可能地阻礙了跨性別醫療保健的進展。

<!-- Yet, progress continues, and every few years we learn a little bit more. -->
然而，進步仍在繼續，每隔幾年我們就會學到更多東西。

<!-- What we know for certain is that it is not a psychological condition. It is not something caused by trauma or by any external influence; nothing can make a person transgender. It happens in the womb, and is not something that a person can choose to be, any more than they could choose their race or their eye color. It has nothing to do with sexual orientation, it has nothing to do with kinks or fetishes, and it has nothing to do with social influences from their parents or from their peers. [Transgender children are as firm in their identities as cisgender children are](https://www.forbes.com/sites/dawnstaceyennis/2020/12/29/study-transgender-children-recognize-their-authentic-gender-at-early-age-just-like-other-kids/#20bbb14526bf). -->
我們可以肯定的是，這不是一種心理疾病。它不是由創傷或任何外在影響引起的；沒有任何東西可以使一個人成為跨性別者。它發生在子宮內，不是一個人可以選擇的，就像他們無法選擇自己的種族或眼睛顏色一樣。它與性取向無關，與禁羈(kink)或戀物癖無關，也與來自父母或同儕的社會影響無關。[跨性別兒童的性別認同與順性別兒童一樣堅定](https://www.forbes.com/sites/dawnstaceyennis/2020/12/29/study-transgender-children-recognize-their-authentic-gender-at-early-age-just-like-other-kids/#20bbb14526bf)（英文）。