Height data tends to be split by gender.

身高數據往往按性別分列。

So, we'll look at women for now.

所以，我們現在先看看女性。

Okay, we're ready.

好了，我們準備好了。

We'll chart heights by country.

我們將按國家列出身高。

Let's look at where my dad's family is from: South Korea.

讓我們來看看我爸爸的老家：韓國。

The average woman born near the beginning of the 1900s like my great grandmother was just 142 centimeters or 4'7".

像我的曾祖母一樣，出生於 20 世紀初的女性的平均身高只有 142 公分（4 英尺 7 英寸）。

For comparison, the average American woman was 159 centimeters or 5'2".

相比之下，美國女性平均是 159 釐米或 5 英尺 2 英寸。

If we chart every country...

如果我們將每個國家都繪製成圖...

we can see that people a century ago were pretty short for today's standards.

我們可以看到，一個世紀前的人們以今天的標準來看都很矮。

But over the next hundred years, humans grew.

但在接下來的一百年裡，人類不斷長高。

Let's just look at those blue bars:

讓我們看看這些藍色柱子：

How much each country grew.

每個國家的增長情況。

We need to adjust the vertical axis so we can see this chart better.

我們需要調整縱軸這樣我們就能更清楚地看到這張圖表了。

Ah, that's better.

啊，這樣好多了。

Many of the countries that saw the most growth were European, North American countries.

許多增長最快的國家是歐洲和北美國家。

For example, here's France and here's the US.

例如，這個是法國，這個是美國。

The countries that grew the least were in Africa.

增長最少的國家在非洲。

And Asian countries were mostly in the middle.

而亞洲國家大多處於中間位置。

But all the way on the right is an outlier.

但在右邊的是一個離群值。

A country where women grew nearly 8 inches in the last century.

上個世紀，這個國家的女性身高增加了近 8 英寸。

South Korea.

韓國。

And South Korean boys grew nearly 6 inches in that time period.

韓國男孩在那段時間長高了近 6 英寸。

So why did humans grow so much in such a short amount of time?

那麼，人類為什麼會在這麼短的時間內這高這麼多？

And why did this happen in South Korea?

為什麼會發生在韓國？

For most of the last 2000 years, human height didn't change much.

在過去 2000 年的大部分時間裡，人類的身高變化不大。

This chart shows the height of European men, but this stagnation pretty much was happening everywhere.

這張圖表顯示了歐洲男性的身高，但這種停滯不前的現象幾乎無處不在。

But in the last 200 years, we started to see some growth.

但在過去的 200 年裡，我們開始看到一些增長。

Here's some better data of 1800s.

這是 1800 年代的一些更好的數據。

You can see people in wealthier European countries starting to get taller.

你可以看到歐洲富裕國家的人們開始長高了。

We know a lot about why.

我們知道很多原因。

And it all starts with our genes.

而這一切都源於我們的基因。

One study from 2006 looked at thousands of siblings and analyzed how much of their DNA was shared, and compared that to how different their height was.

2006 年的一項研究對數千名兄弟姐妹進行了觀察，分析了他們的 DNA 有多少是相同的，並將其與他們的身高差異進行了比較。

They found that about 80% of the difference in sibling height is genetic.

他們發現，兄弟姊妹身高的差異約 80% 是遺傳因素。

But that other 20% are external forces that affect our height.

但另外20%是影響我們身高的外在力量。

Because even if our DNA says we can grow to a certain height during puberty, that growth is often interrupted.

因為即使我們的 DNA 顯示我們可以在青春期生長到某個高度，但這種生長經常會中斷。

There's a great study that tracks English and Welsh boys born in the 1890s.

有一項很棒的研究追蹤了 1890 年代出生的英國和威爾士男孩。

Many of these boys eventually enlisted in WWI, which created a record of their adult height.

這些男孩中的許多人最終參加了第一次世界大戰，這創造了他們成年身高的記錄。

Researchers compared that to their childhood living conditions using the 1901 census.

研究人員將其與 1901 年人口普查中他們的童年生活條件進行了比較。

They found that, if a person grew up in a white-collar household, which probably had better access to nutrition, they were on average about a half inch taller than everyone else.

他們發現，如果一個人在白領家庭長大，可能有更好的營養來源，那麼他平均比其他人高約半英寸。

If they grew up in a crowded home where they were more likely to spread disease or infection, they were nearly a third of an inch shorter.

如果他們在擁擠的家庭中長大，那裡更容易傳播疾病或感染，他們的身高就會矮近三分之一英寸。

And if they grew up in an industrial area, exposed to pollution and disease, they were nearly an inch shorter.

如果他們在工業區長大暴露於汙染和疾病中，他們矮了近一英寸。

Even within the same country, the environment had a noticeable effect on people's height.

即使在同一個國家環境對人們的身高有明顯的影響。

That's what changed drastically in the last 200 years.

這就是過去 200 年來發生的巨大變化。

Over the last century, we made massive advancements in nutrition, sanitation medicine and overall quality of life.

上個世紀，我們在營養、衛生醫學和整體生活品質方面取得了巨大進步。

And humans got way taller.

人類也長得更高了。

But now let's put South Korea on this chart.

但是，現在讓我們把韓國放在這個圖表上。

100 years ago, South Korea was poor and the people were shorter than the global average.

100年前，韓國很窮，人口也比全球平均矮。

But by the 1960s, they had mostly caught up.

但到了 1960年代，他們大多已經迎頭趕上。

Then something drastic happened.

然後，戲劇性的事情發生了。

A military-led government focused on economic growth.

軍方領導的政府專注於經濟成長。

Eventually, the country shifted from producing things like textiles to consumer electronics and cars.

最終，該國從生產紡織品等轉向生產消費性電子產品和汽車。

And South Korean wealth skyrocketed.

韓國的財富也隨之暴漲。

In the 60s, many South Koreans didn't have enough to eat.

1960 年代，許多韓國人吃不飽飯。

The food supply was basically in line with other low-income countries.

糧食供應與其他低收入國家基本一致。

But the food supply rapidly improved and soon it exceeded the world average.

但糧食供應迅速改善，很快就超過了世界平均水準。

And then it caught up to affluent countries in Europe.

然後，它又趕上了歐洲的富裕國家。

As for childhood health, in the 1950s, more than 20% of South Korean kids died before age one.

至於兒童健康，在 20 世紀 50 年代，超過 20% 的韓國兒童在一歲前死亡。

Worse than most low income countries.

比大多數低收入國家還糟糕。

Then, South Korea's infant mortality plummeted.

隨後，韓國的嬰兒死亡率急劇下降。

And as a result of these improved conditions, especially for children, South Koreans kept growing and growing.

由於這些條件的改善，尤其是兒童的條件的改善，韓國人不斷成長。

I want to show you one more chart.

我想再給你們看一張圖表。

This is the height of South Koreans and North Koreans in the 1930s.

這是1930年代南韓人和北韓人的身高。

Back then, they were one country so naturally they were about the same height.

那時，他們是一個國家，所以他們的身高自然差不多。

The North is where my maternal grandparents and their siblings grew up.

北方是我的外祖父母和他們的兄弟姊妹長大的地方。

Then in 1945 the North and South were split up.

然後在 1945 年南北分裂。

In 1950, the Korean War began.

1950 年，朝鮮戰爭爆發。

The war ended in a stalemate and North Korea shut its borders walling itself off from the rest of the world.

戰爭陷入僵局，北韓關閉了邊界，將自己與世界其他地區隔離。

In the 1990s, millions of North Koreans starved to death.

1990 年代，數百萬北韓人餓死。

We only have data on North Korean height today because of the thousands of people who escaped to the South during that period.

我們現在會有北韓身高的數據，是因為在那段時期有數千人逃往南韓。

And in the generations since the division, the height gap between the two Koreas has continuously widened.

並且自分裂以來的幾個世代中，南北韓的身高差距不斷拉大。

My grandparents were lucky.

我的祖父母很幸運。

Early in the war, they fled their home in North Korea, and escaped to the southern tip of South Korea.

戰爭初期，他們逃離了在北韓的家，並逃往南韓的南部。

And a few years later, my mother was born.

幾年後，我的母親出生了。

My mom is a bit taller than her mother, and my generation is taller than hers.

我媽媽比她媽媽高一點.，我這一代人又比她高。

Height is inherited, written into our very genetic code.

高度是遺傳的，寫入了我們的基因密碼。

But height is also something history gives to us.

但身高也是歷史賦予我們的。