- I'm a cis-man and I like fun shirts. - You do.

- 我是生理男性，而且我喜歡有趣的衣服。 - 你真的很喜歡。

Our gender plays a big role in how we define ourselves and others.

我們的性別對於自己和他人的定義扮演了很重要的角色。

But it's not something science fully understands.

但這不是完全可以用科學解釋的。

And, funnily enough, we don't really know why I like fun shirts, either, but no one questions that so let's just move on.

其實我們並不知道我為何喜歡有趣的衣服，或者是因為沒有人質疑這一點，因此我們不會仔細探究。

A lot of us may never really think twice about defining ourselves as a man or a woman, but there are many who do think about it, a lot.

多數人可能從來不會質疑我們定義自己是男性還是女性，但也有很多人會很認真思索這件事情，真的很認真的想。

In reality a lot of biological, sociological, and psychological factors go into the definitions of “man” or “woman,” or neither.

事實是，很多生理的、社會的，或是心理的因素會影響我們定義自己為男性、女性或是其他。

For example, when babies are born at a hospital, they're assigned a sex based on primary sex characteristics, like genitalia.

例如，嬰兒在醫院出生時，他們會根據首要的性別特徵，像是生殖器官等等的，而被指派一個生理性別。

Yeah. Someone literally looks at the baby and makes a decision.

沒錯，有人真的看著嬰兒並做出決定。

They're mainly going by visual inspection.

他們主要採取視覺檢查的方式。

And though hormones like testosterone play a big role in developing the primary sex organs that you have at birth,

儘管睪固酮這類的荷爾蒙，在出生時主要生殖器官的發展上扮演重要角色，

sexual differentiation continues beyond birth,

其實性別的改變會在出生之後持續進行，

with a lot of outwardly visible changes, and awkwardness, peaking at puberty.

並有很多外顯可見的改變，和尷尬感，在青春期會達到巔峰。

And these processes rely on a whole host of hormones, and receptors, and other factors that come from at least 70 different genes on different chromosomes.

這些過程需要仰賴一系列的荷爾蒙、接收器，和其他來自至少 70 種不同染色體上的基因所形成的因素。

So really, biological sex is not black or white because there are so many variables going into it that are not necessarily correlated with one another.

所以說真的，生理性別並非黑白分明的事情，因為實在有太多彼此不太相關的變數需要被考慮進去。

Which is why there's good evidence to say there are more than two biological sexes.

也就是說，有證據顯示其實有多於兩種的生理性別。

For example, testosterone is important for developing the internal genitalia, but it needs to be converted by an enzyme for the external genitalia to be made.

舉例來說，睪固酮對於內生殖器官的發展是很重要的，但它需要被酶轉化才能使外生殖器官得以形成。

So someone could have testosterone, plus all the effects that leads to during development through puberty, and be “male” in a lot of ways internally.

某人可能因為睪固酮和其所造成的影響，而經過青春期發展階段後，使得他的內在有許多「男性」特質。

But because they're missing one enzyme, things might look a little different on the outside.

但因為他們少了一個酶當作催化劑，使得外在看起來可能有點不太一樣。

The thing is, most people don't know their genetics or what's going on inside of their abdomen.

其實大部分的人不清楚自己的基因，或是腹腔裡面到底發生什麼事。

So how come anyone confidently proclaim, well anything, when it comes to gender?

所以一個人怎麼會很有自信的宣稱，他知道關於性別的任何資訊呢？

When I say I'm a woman, I'm actually referring to my gender identity.

當我說我是名女性時，我其實指的是我的性別認同。

This might be related to or influenced by primary or secondary sex characteristics, but knowing our gender identity comes from the brain.

這或許和第一或第二性別特徵的影響有關，但我們的性別認同其實來自大腦。

The fascinating thing is we don't really know a ton about what influences this identity.

有趣的是，我們沒有很瞭解到底是什麼東西影響了我們對自己的認知。

Like how I might say, "I'm a confident or anxious person."

像我可能會說：「我是一個有自信或者焦慮的人。」

But I don't really know what exactly in my brain makes me like that.

但我並不知道大腦裡的什麼東西讓我變成那個樣子。

There are a few regions in the brain that are different between sexes, including the interstitial nucleus of the anterior hypothalamus and the bed nucleus of stria terminalis, which is part of the limbic system.

不同性別的大腦有一些區域是不一樣的，像是前下視丘的間質核和終紋床核，它們屬於邊緣系統的一部份。

In men, these areas are both larger and have more neurons in them.

對於男性而言，這些區域都比較大，裡面也有比較多神經元。

And studies to date, albeit small ones, do show the sizes of these areas correlate with the gender identities of transgender men and women.

而至今的研究，儘管規模不大，但仍足以顯示這些區域的大小和跨性別男性和女性的性別認同是相關的。

Other studies have found differences in white matter microstructures between men and women.

其他研究也發現男女間白質微觀結構的不同。

Transgender men who have not yet received hormone treatments had patterns more similar to those sharing their gender identity, not what they were assigned at birth.

還未接受荷爾蒙療法的跨性別男性的特質，和那些與他們性別認同一樣的人相似，而不是和其他相同生理性別的人。

In other words, the sex they were assigned at birth didn't accurately predict their white matter patterns.

也就是說，生理性別並沒有精準預測他們白質的樣子。

While there are so many different areas of the brain that seem different between men and women, some researchers argue that there are more similarities than differences and there isn't really a typical “male” or “female” brain.

儘管男女有很多大腦的區域看起來不一樣，有些研究人員認為相同處仍大於不同，而且其實沒有典型的男性或女性大腦。

But given that, all of us have incomplete information on our true biological sex, and that we don't fully understand the neuroscience behind gender.

但考量到我們只有自己真正生理性別的不完整資訊，而且我們不全然瞭解性別背後的神經科學。

Or any complex trait, like why you like this fun shirt.

或是任何複雜的特質，像你為何喜歡這件有趣的衣服。

True. It doesn't make sense to burden some individuals with proving how they feel.

沒錯，讓其他人為自己的感受負起舉證責任並不合理。

Because scientifically, none of us can explain why we feel like a man or a woman.

因為就科學而言，沒有人能解釋我們為什麼感覺是男性或女性。

And as none of us can say that, by making a minority of people try to prove that with a burden of proof, we're causing a lot of health problems.

就因為沒有人能完全確定，讓少數人試著負起舉證責任造成了很多健康的問題。

For example, the suicide attempt rate among transgender people ranges from 32–50% in a number of different countries,

例如，跨性別族群的嘗試自殺率在許多國家是介在百分之 32 到 50 之間，

whereas the overall population average in the US is estimated around 0.04 to 1.1%.

而在美國的平均數據約佔總人口的百分之 0.04 到 1.1 之間。

Both of these numbers are too high, but the stats for transgender people are particularly so, especially when recent studies show these numbers decrease when transgender people are socially accepted.

這兩個數字都太高了，尤其對於跨性別族群的數據而言，特別是最近研究顯示若跨性別者在社會更被接受，這些數字會下降。

While there are, of course, a lot more scientific questions to ask, we could save hundreds of thousands of lives by removing social stigma.

雖然當然還有很多的科學問題值得探討，我們可以拯救上千上百的生命，只要我們去除對他們的社會成見。

We know that science will catch up eventually, but in the meantime we should all recognize that this is more complicated than man, woman, trans or non-binary.

我們知道科學最終會跟上社會的腳步，但同時我們都應該意識到這問題比男性、女性、跨性別、和非二元性別的分類還要更複雜。

And as is the norm in science, the more we learn, the more nuanced it gets.

這就是科學的常態，當我們學的越多，就會有越多細節浮現。

And that diversity in people and ideas is what makes this world so cool.

而人的多樣性和想法是讓這個世界更精彩的原因。

If you wanna learn more about what your DNA says about your sexuality, different than identity, click here.

若你想知道更多 DNA 和不是性別認同的性向之間的關係，請點這裡。

Thank you for watching. I'm sure you'll have a comment on this video,

感謝收看，我相信你會想要在這支影片留言，

so make sure you leave it below, and share the video too.

所以請在下方留言，並分享這支影片。