terrible grades.

糟糕的成績。

Her dad leans over her shoulder to take a peek at the academic horror show.

她的父親靠在她的肩膀上，偷看了這場學術恐怖秀。

The girl turns around and asks: So what do you think dad?

女孩轉身問道。那麼你覺得爸爸怎麼樣？

Nature or nurture?

天生的還是後天的？

Centuries ago, John Locke and others, began arguing that our personality is mainly shaped

幾個世紀前，約翰-洛克和其他人開始論證，我們的個性主要是由以下因素形成的

by the environment we were raised in.

由我們成長的環境決定。

Others, such as Charles Darwin, believed that we are largely programmed genetically.

其他人，如查爾斯-達爾文，認為我們在很大程度上是由基因決定的。

Modern behavioral geneticists think that it's more complex - because the two interact.

現代行為遺傳學家認為它更復雜--因為兩者相互影響。

And relatively recently, a little crayfish from Germany, showed just how little we actually

而相對而言，最近，來自德國的一隻小龍蝦，顯示了我們實際上是多麼的渺小

know — but more about her later.

知道 - 但以後會有更多關於她的資訊。

First, let's go back to the girl, her dad and what we do know.

首先，讓我們回到這個女孩，她的父親和我們所知道的情況。

Neither the dad, nor the smartest scientists, can answer what leads to certain school outcomes

無論是爸爸，還是最聰明的科學家，都無法回答是什麼導致了某些學校的結果

of our 7-year old girl.

我們7歲的女孩。

We do know, however, a bit about the influences of genes and the environment when it comes

然而，我們確實知道一些關於基因和環境的影響，當它涉及到

to groups of specific populations.

對特定人群的群體。

Take, for example, a group of 100 white American men in their early twenties and you will probably

以100名20歲出頭的美國白人男子為例，你可能將

find, on average, an IQ of 100, a height of 178 cm or around 5.8 feet, and that ten have

發現，平均而言，智商為100，身高為178釐米或5.8英尺左右，有10人擁有

spelling problems.

拼寫問題。

We can now ask which of these 3 traits is determined by genes — anything that happened

我們現在可以問，在這3種性狀中，哪一種是由基因決定的--發生的任何事情

before conception, often referred to as nature; and which by the environment— anything that

在受孕之前，通常被稱為自然；而在環境中，則被稱為任何東西。

happened after their mothers got pregnant, often referred to as nurture.

發生在他們的母親懷孕之後，通常被稱為養育。

To understand the two forces,  we need to acknowledge 

為了理解這兩種力量，我們需要承認

that environmental influences are often random

環境的影響往往是隨機的

— siblings experience home very differently.

- 兄弟姐妹們對家的體驗非常不同。

And we need to recognize that genes are complex — there is no single gene doing a single

我們需要認識到，基因是複雜的--沒有一個基因可以做一個單一的

thing.

事。

We therefore know little about which trait in an individual is the result of their genetic

是以，我們對一個人身上的哪種特徵是其遺傳的結果知之甚少。

makeup and which is due to the environment.

構成，哪些是由於環境造成的。

We only know about the impact of nature and nurture on trait differences of a particular

我們只知道自然和教養對某一特定性狀差異的影響。

group.

組。

And to learn about that, we need to understand heritability.

而要了解這一點，我們需要了解遺傳性。

Heritability is a factor that ranges between one and zero.

遺傳性是一個在1和0之間的因素。

One stands for genetic influences.

一個是代表遺傳的影響。

Zero for environmental factors.

環境因素為零。

Heritability defines the genetic impact on trait differences in a particular population.

遺傳性定義了特定人群中對性狀差異的遺傳影響。

It can not measure the degree to which a trait of a particular individual is genetic.

它不能衡量一個特定個體的特徵在多大程度上是遺傳的。

Dyslexia, for example, has a heritability closer to 1.

例如，閱讀障礙症的遺傳率接近1。

That means that genes explain more of the difference in spelling mistakes of our group

這意味著基因可以解釋我們組的拼寫錯誤的更多差異

than school, family or random factors.

而不是學校、家庭或隨機因素。

It does not mean that one particular person with spelling problems got them genetically.

這並不意味著某個有拼寫問題的人是通過遺傳得到的。

Some just didn't get much support when they were young.

有些人只是在年輕時沒有得到很多支持。

How complex the interaction between genes and environment really is becomes clear when

基因和環境之間的相互作用到底有多複雜，在以下情況下會變得很清楚

we look at something as seemingly straightforward as IQ and height.

我們看一下像智商和身高這樣看似簡單的東西。

First, let's examine height.

首先，讓我們研究一下高度。

A group of 100 white American male students are on average 178 centimeters tall — that's

一組100名美國白人男學生的平均身高為178釐米--這就是

roughly five feet, 10 inches.

大約5英尺10英寸。

Their heritability for height is around 0.8.

他們的身高遺傳率約為0.8。

If some men in this group are 183 cm — or six feet tall, then heritability allows us

如果這個群體中的一些男性是183釐米--或六英尺高，那麼遺傳性使我們能夠

to assume that 80% of that difference is, on average, caused by genetic variants and

假設這種差異的80%平均是由基因變異引起的。

20% of the difference is due to lifestyle.

20%的差異是由於生活方式造成的。

If the same group of people were raised in a region that experienced systemic droughts

如果同一批人是在經歷過系統性乾旱的地區長大的

and they never had enough to eat, their potential for an average height of 178 centimeters is

而且他們從來沒有吃飽過，他們平均身高178釐米的潛力是

far from ever being reached.

遠遠沒有達到。

The heritability for height might now go from 0.8 down to 0.5.

身高的遺傳率現在可能從0.8下降到0.5。

Nature and nurture are now equally responsible for group differences.

現在，天性和教養對群體差異負有同等責任。

This means, heritability changes.

這意味著，遺傳性會發生變化。

If we have a well nourished population on the one side and a malnourished group on the

如果我們一邊是營養良好的人口，一邊是營養不良的群體

other, then the impact of nutrition on the differences in height changes from 20% to

其他，那麼營養對身高差異的影響就會從20%變成

50%.

50%.

In other words, nurture matters a lot, until we reach a point from which it's not as relevant.

換句話說，培養很重要，直到我們達到一個點，從這個點開始它就不那麼重要了。

So what about intelligence?

那麼智力呢？

The heritability of IQ is around 0.6 for people in their twenties and then increases as we

對於20多歲的人來說，智商的遺傳率約為0.6，然後隨著我們的成長而增加。

age.

年齡。

The average IQ in our group will be around 100.

我們小組的平均智商將達到100左右。

But some have an IQ of 110.

但有些人的智商達到了110。

Genes are therefore responsible for 60% of the difference, and random factors and the

是以，基因要對60%的差異負責，而隨機因素和

environment for about 40%.

環境約為40%。

In other words, for those with an IQ of 110, 6 of the additional 10 points, can, on average,

換句話說，對於那些智商為110的人來說，額外的10分中的6分，平均來說可以。

be attributed to nature and 4 points to nurture.

歸功於自然，4分歸功於培養。

Now even if nurture plays a big role, it doesn't mean that teachers or parents had any impact.

現在，即使教養髮揮了很大的作用，也不意味著教師或父母有任何影響。

Unlike height, which we know how to increase through nutrition, when it comes to IQ we

與身高不同的是，我們知道如何通過營養來增加身高，當涉及到智商時，我們

don't know much about how to improve it.

不太瞭解如何改進它。

Random factors seem to play a big role.

隨機因素似乎起了很大作用。

How random the environment is, becomes clear when we look at two kids that are born into

當我們看兩個孩子出生時，就會明白環境是多麼隨機。

the same family.

同一個家庭。

Both are raised in the same shared environment, but firstborns, on average, turn out to be

兩者都是在相同的共享環境中長大，但頭胎平均來說，會變成

more intelligent than their younger siblings.

比他們的弟弟妹妹更聰明。

And if one of two siblings was adopted, the two would have some correlation in IQ during

而如果兩個兄弟姐妹中的一個是被收養的，那麼這兩個人的智商就會有一定的關聯性。

their upbringing, but as adults they would be hardly more similar in intelligence than

他們的成長經歷，但作為成年人，他們的智力幾乎不會比

complete strangers.

完全陌生的人。

Parents, it seems, have a very limited impact on a child's IQ.

看來，父母對孩子的智商影響非常有限。

So now what about that crayfish?

那麼現在那隻小龍蝦呢？

In 1995 German scientists made an odd observation.

1995年，德國科學家做出了一個奇怪的觀察。

The little female creature had mutated and become asexual — able to make clones of

這隻小雌性生物已經變異，成為無性繁殖--能夠製造克隆人

itself.

本身。

As each clone shared exactly the same genetic blueprint, the scientists set up an experiment

由於每個克隆人都擁有完全相同的基因藍圖，科學家們設立了一個實驗

for the ultimate test.

為最終的測試。

Hundreds of these little identical creatures were placed in the same environment.

數以百計的這些相同的小生物被放置在同一環境中。

Same water, same temperature, same amount of food.

同樣的水，同樣的溫度，同樣的食物量。

Even though the scientists tried to control all these variables, the unthinkable happened.

儘管科學家們試圖控制所有這些變量，但不可想象的事情還是發生了。

Some crayfish stayed tiny, others grew big.

有些小龍蝦一直很小，有些則長得很大。

Some died, others lived on and on.

一些人死了，另一些人則活得很好。

And while some became social, others enjoyed solitude.

而當一些人成為社會人時，另一些人則享受孤獨。

Why do you think that happened?

你認為為什麼會發生這種情況？

Is that nature, nurture or a complex interplay of the two with some random variations in

這到底是天性、教養還是兩者的複雜相互作用，以及一些隨機的變化？

replicated genetic code?

複製的遺傳密碼？

To download this video without background music, and to learn more about the topic,

要下載這個沒有背景音樂的視頻，並瞭解更多關於這個主題的資訊。

visit SproutsSchools.com

訪問SproutsSchools.com

This and all other Sprouts' videos are  licensed under the Creative Commons.  

本視頻和所有其他Sprouts的視頻都在知識共享協議下授權。

That means teachers from all around the world  can use them in classrooms, online courses or 

這意味著世界各地的教師都可以在教室、在線課程或其他場合使用它們。

to start projects - and  today, thousands already do!

來啟動項目--而今天，成千上萬的人已經開始這樣做了!

To learn how it works and download this  video without Ads or background music,  

要了解它是如何工作的，並下載這個沒有廣告或背景音樂的視頻。

checkout our website or  read the description below.

查看我們的網站或閱讀下面的描述。

If you want to support our  mission and help change education 

如果你想支持我們的使命並幫助改變教育

visit our Patreon - that's patreon.com/sprouts.

請訪問我們的PATREON - 即patreon.com/sprouts。