How does income affect childhood brain development? | Kimberly Noble

翻译人员: Nancy Cai 校对人员: Yolanda Zhang

What I'm about to share with you are findings from a study

我要和你们分享 一项研究的成果，

of the brains of more than 1,000 children and adolescents.

这项研究是关于 1000个儿童和青少年的大脑。

Now, these were children who were recruited

这些参与研究的儿童

from diverse homes around the United States,

来自美国不同的家庭，

and this picture is an average of all of their brains.

这张图片代表了 一个普通的大脑，

The front of this average brain is on your left

图片中大脑的前面 相当于你的大脑左侧，

and the back of this average brain is on your right.

后面相当于你的大脑右侧。

Now, one of the things we were very interested in

我们想要研究的事情之一

was the surface area of the cerebral cortex,

就是大脑皮层的表面积，

or the thin, wrinkly layer on the outer surface of the brain

就是大脑外表面 薄薄的皱巴巴的一层，

that does most of the cognitive heavy lifting.

它主要负责认知功能。

And that's because past work by other scientists has suggested

曾经有科学家的研究表明，

that in many cases,

在许多情况下，

a larger cortical surface area

皮层的表面积越大，

is often associated with higher intelligence.

代表着智商越高。

Now, in this study, we found one factor

在这次的研究中，我们发现

that was associated with the cortical surface area

有一个因素 和整个大脑表面的

across nearly the entire surface of the brain.

皮层表面积有关联，

That factor was family income.

这个因素就是家庭收入。

Now, here, every point you see in color is a point where higher family income

这上面，你看到的每一个 彩色的点都代表着

较高的家庭收入和 较大的表层面积是相关联的，

was associated with a larger cortical surface area in that spot.

And there were some regions, shown here in yellow,

还有一些区域， 这些黄色的，

where that association was particularly pronounced.

是这种关联 尤其明显的地方，

And those are regions that we know support a certain set of cognitive skills:

这些区域也是据我们所知 负责一些特定的认知功能的区域：

language skills like vocabulary and reading

语言能力，词汇和阅读，

as well as the ability to avoid distraction

避免分心的能力，

and exert self-control.

还有进行自我约束的能力。

And that's important,

这个很重要，

因为这些能力

because those are the very skills

恰恰是贫困的孩子 最有可能欠缺的。

that children living in poverty are most likely to struggle with.

In fact, a child living with poverty

事实上，一个贫困的孩子，

is likely to perform worse on tests of language and impulse control

在两岁之前，就有可能在 语言测试和控制冲动的测试中

before they even turn two.

显现出劣势。

Now, there are a few points I'd like to highlight about this study.

关于这项研究，我想强调几点。

Number one:

第一，

this link between family income and children's brain structure

家庭收入和儿童 大脑结构之间的这种关联，

was strongest at the lowest income levels.

在最低收入水平人群中 是最明显的，

So that means that dollar for dollar,

这意味着，在同一个标准下，

relatively small differences in family income

在最贫困的家庭中，

were associated with proportionately greater differences in brain structure

家庭收入相对较小的差异，

among the most disadvantaged families.

会带来大脑结构上较大的差异。

直觉上，这是有道理的，对吧？

And intuitively, that makes sense, right?

An extra 20,000 dollars for a family earning, say, 150,000 dollars a year

假设一个家庭年收入是15万美元， 再有额外的2万美元

would certainly be nice, but probably not game-changing,

当然会更好， 但是可能不影响大局。

whereas an extra 20,000 dollars

但是假设一个家庭 年收入只有2万美元，

for a family only earning 20,000 dollars a year

那么这额外的2万美元，

would likely make a remarkable difference in their day-to-day lives.

就很可能给他们的生活 带来显著的改变。

Now, the second point I'd like to highlight

我想强调的第二点，

is that this link between family income and children's brain structure

就是家庭收入和儿童大脑结构 之间的这种关联，

didn't depend on the children's age,

并不取决于儿童的年龄，

it didn't depend on their sex

性别，

and it didn't depend on their race or ethnicity.

种族，或是民族。

And the final point --

最后一点，

and this one's key --

这点很重要，

there was tremendous variability from one child to the next,

每两个孩子之间都有 很大的个体差异，

by which I mean there were plenty of children from higher-income homes

也就是说， 很多高收入家庭的孩子，

with smaller brain surfaces

也有较小的大脑表面积，

and plenty of children from lower-income homes

而很多较低收入家庭的孩子，

with larger brain surfaces.

也有较大的大脑表面积。

Here's an analogy.

打个比方，

We all know that in childhood,

我们都知道，在童年时期，

boys tend to be taller than girls,

男孩一般比女孩高一些，

but go into any elementary school classroom,

但是任何一个小学的班级里，

and you'll find some girls who are taller than some boys.

都有一些女孩比 一些男孩要高。

So while growing up in poverty is certainly a risk factor

所以即使在贫困中成长 会有一定的风险

for a smaller brain surface,

导致较小的大脑表面积，

in no way can I know an individual child's family income

我也并不能由 一个儿童的家庭收入，

and know with any accuracy

准确地判断出

what that particular child's brain would look like.

这个儿童的大脑长什么样子。

I want you to imagine, for a moment, two children.

现在，想象有两个孩子，

One is a young child born into poverty in America;

一个孩子来自美国一个贫困家庭，

the other is also an American child,

另外一个也是美国的孩子，

but one who was born into more fortunate circumstances.

但他的家庭经济境况更好一些。

Now, at birth, we find absolutely no differences

我们并没有发现

他们出生时的大脑有任何区别，

in how their brains work.

But by the time those two kids are ready to start kindergarten,

但当两个孩子到了 上幼儿园的年龄时，

we know that the child living in poverty

我们知道那个贫困中长大的孩子，

is likely to have cognitive scores that are, on average, 60 percent lower

平均会比另一个孩子的认知能力

低60%。

than those of the other child.

Later on, that child living in poverty

后来，那个贫困中长大的孩子，

will be five times more likely to drop out of high school,

从高中辍学的几率要高5倍，

and if she does graduate high school,

假设她真的从高中毕业，

she'll be less likely to earn a college degree.

她获得大学学位的可能性也更低，

By the time those two kids are 35 years old,

等两个孩子都35岁了，

if the first child spent her entire childhood living in poverty,

那个在贫困中长大的孩子

she is up to 75 times more likely to be poor herself.

依然贫困的概率要高出75倍。

But it doesn't have to be that way.

但是这种情况不是必然的，

As a neuroscientist, one of things I find most exciting about the human brain

作为一个神经科学家， 最令我兴奋的一个发现就是，

is that our experiences change our brains.

我们的经历会改变我们的大脑。

Now, this concept, known as neuroplasticity,

这个概念叫做神经可塑性，

means that these differences in children's brain structure

它意味着，儿童 大脑结构的这些区别，

don't doom a child to a life of low achievement.

并不意味着一个孩子的 一生都会碌碌无为，

The brain is not destiny.

大脑并不决定命运。

And if a child's brain can be changed,

而如果一个孩子的大脑能被改变，

then anything is possible.

任何事都是有可能的。

As a society, we spend billions of dollars each year, educating our children.

我们的社会每年都会花费 几十亿美元教育孩子，

So what can we tell schools, teachers and parents

学校，家长，和老师， 都想帮助弱势背景的孩子

who want to help support kids from disadvantaged backgrounds

在学校和生活中过得更好，

那么我们能告诉他们什么呢？

to do their best in school and in life?

Well, emerging science suggests

最新的科学研究证明，

that growing up in poverty is associated with a host of different experiences

在贫困中长大代表着 很多不同的经历，

这些经历放在一起可能会

and that these experiences in turn may work together

to help shape brain development and ultimately help kids learn.

决定大脑的发育， 并最终帮助孩子学习。

And so if this is right,

如果真的是这样，

it begs the question:

那么问题就来了：

Where along this pathway can we step in and provide help?

我们能在这个过程中的 哪一步进行干预并提供帮助呢？

So let's consider first intervening at the level of learning itself --

我们首先考虑一下 在学习阶段干预，

most commonly through school-based initiatives.

这通常是通过 学校的活动实现的。

Now, should we be encouraging teachers to focus on the kinds of skills

我们是否应该鼓励教师着重关注

that disadvantaged kids are most likely to struggle with?

贫困孩子最容易欠缺的技能呢？

Of course.

当然，

The importance of high-quality education based in scientific evidence

以科学证据为基础的高质量教育的

重要性不容小觑。

really can't be overstated.

And there are a number of examples of excellent interventions

而且有很多干预成功的例子，

targeting things like literacy or self-regulation

针对识字能力或自我约束，

that do in fact improve kids' cognitive development and their test scores.

成功地提高了孩子的 认知能力和测试分数。

But as any intervention scientist doing this work would tell you,

但是所有从事这类研究的 科研者都会告诉你，

this work is challenging.

这项工作很有挑战性，

It's hard to implement high-quality, evidence-based education.

以科学证据为基础的 高质量教育很难实施，

And it can be labor-intensive,

有可能需要很大的人力投入，

it's sometimes costly.

有时费用高昂。

And in many cases, these disparities in child development emerge early --

并且在许多情况下，这些儿童 发育的差距很早就显现了——

well before the start of formal schooling --

早在他们开始正式的 学校教育之前，

sometimes when kids are just toddlers.

有时甚至在幼儿时期。

And so I would argue:

所以我的观点是，

school is very important,

学校很重要，

but if we're focusing all of our policy efforts

但如果我们把所有的政策工作

都集中在正规学校教育上，

on formal schooling,

we're probably starting too late.

可能为时已晚了。

So what about taking a step back

那么我们能不能退后一步，

and focusing on trying to change children's experiences?

着眼于改变儿童的成长经历呢？

What particular experiences are associated with growing up in poverty

有哪些经历是 与在贫困中成长有关，

and might be able to be targeted to promote brain development

并且能被干预，以促进孩子的

and learning outcomes for kids?

大脑发育和学习效果呢？

Of course, there are many, right?

当然，有很多，对吧？

Nutrition, access to health care,

营养，医疗资源，

exposure to second-hand smoke or lead,

二手烟污染或铅污染，

experience of stress or discrimination,

有压力的环境或者受到歧视，

to name a few.

等等。

In my laboratory,

在我的实验室里，

we're particularly focused on a few types of experiences

我们特别关注几种类型的经历，

that we believe may be able to be targeted

我们认为这些经历 也许能够被干预

to promote children's brain development

以促进儿童大脑发育，

and ultimately improve their learning outcomes.

并最终提升他们的学习成果。

As one example,

举一个例子，

take something I'll call the home language environment,

有一样东西叫做家庭语言环境，

by which I mean, we know that the number of words kids hear

我们知道，孩子们 听到的词汇的数量

and the number of conversations they're engaged in every day

和他们每天 进行的对话数量

can vary tremendously.

可能差异很大。

By some estimates,

据估计，

kids from more advantaged backgrounds

来自更有优势背景的孩子们，

hear an average of 30 million more spoken words

在前几年中，

in the first few years of life

与较弱势群体的孩子相比，

compared to kids from less advantaged backgrounds.

平均会多听到 3000万个口语词汇。

Now, in our work, we're finding

在我们的研究中发现，

that kids who experience more back-and-forth,

进行更多双向对话的孩子，

responsive conversational turns

大脑控制语言

tend to have a larger brain surface in parts of the brain

和阅读能力的区域

that we know are responsible for language and reading skills.

有更大的表面积。

And in fact, the number of conversations they hear

事实上，他们 听到的对话的数量，

seems to matter a little bit more than the sheer number of words they hear.

比他们听到的词汇的数量， 似乎还更重要一些，

So one tantalizing possibility

所以有一种令人欣喜的可能，

is that we should be teaching parents not just to talk a lot,

就是我们要教给父母们， 不仅要多说话，

but to actually have more conversations with their children.

而且要和他们的孩子 多进行对话。

In this way, it's possible that we'll promote brain development

这样有可能促进孩子的大脑发育，

and perhaps their kids' language and reading skills.

并提高孩子的语言和阅读能力。

And in fact, a number of scientists are testing

事实上，许多科学家现在正在测试

that exciting possibility right now.

这个令人振奋的方法是否可行。

But of course, we all know

但是，我们当然都知道，

that growing up in poverty is associated with lots of different experiences

在贫困中长大代表着 很多不同的经历，

beyond just how many conversations kids are having.

不仅仅是孩子 进行了多少对话，

So how do we choose what else to focus on?

那么我们如何选择 别的关键点呢？

The list can be overwhelming.

各种因素可能太多了。

There are a number of high-quality interventions

有很多更高质量的干预方法，

that do try to change children's experience,

试图改变孩子的经历，

many of which are quite effective.

其中不乏相当有效的方法。

But again, just like school-based initiatives,

但是，就像学校主导的方式一样，

this is hard work.

它并不容易，

It can be challenging,

有很多挑战，

it can be labor-intensive,

需要人力投入，

sometimes costly ...

有时费用高昂…

and on occasion,

而且有时，

it can be somewhat patronizing for scientists to swoop in

科学家们介入一个家庭， 告诉他们需要怎么改变

and tell a family what they need to change in order for their child to succeed.

才能让他们的孩子成功， 会显得有些冒昧。

So I want to share an idea with you.

所以我想和你们分享一个想法，

What if we tried to help young children in poverty

我们能不能仅仅通过 给贫困孩子的家庭捐款

by simply giving their families more money?

来帮助他们呢？

I'm privileged to be working with a team of economists,

我有幸和一些经济学家，

social policy experts and neuroscientists

社会政策专家和神经科学家一起合作

in leading Baby's First Years,

共同负责“孩子的最初阶段”这个实验，

the first-ever randomized study

这是首个探究减轻贫困

to test whether poverty reduction causes changes in children's brain development.

能否改变孩子的大脑发育的随机实验。

Now, the ambition of the study is large,

这项研究的目标很大，

but the premise is actually quite simple.

但它的前提实际上很简单。

In May of 2018,

从2018年5月起，

we began recruiting 1,000 mothers living below the federal poverty line

我们开始在美国的各个医院 招募1000名刚刚生过孩子的

shortly after they gave birth in a number of American hospitals.

生活在国家贫困线以下的母亲。

Upon enrolling in our study,

在参与我们的实验后，

all mothers receive an unconditional monthly cash gift

所有的妈妈在孩子 出生后的前40个月，

for the first 40 months of their children's lives,

每个月都会收到一笔 无条件的现金礼物，

and they're free to use this money however they like.

她们可以任意支配这笔钱。

But importantly, mothers are being randomized,

但有一点很重要， 这些妈妈是随机挑选的，

so some mothers are randomized to receive a nominal monthly cash gift

有些妈妈每个月会 收到很少的一笔钱，

and others are randomized to receive several hundred dollars each month,

而其他的妈妈则被随机挑选为 每个月收到几百美金，

an amount that we believe is large enough

我们觉得这笔钱足够

to make a difference in their day-to-day lives,

给她们的日常生活带来改变，

in most cases increasing their monthly income by 20 to 25 percent.

在多数情况下，这会使她们的 月收入提高20%到25%。

So in this way,

通过这种方式，

we're hoping to finally move past questions

我们希望能跳脱出

of how poverty is correlated with child development

贫困是否和儿童发展相关联的问题，

and actually be able to test whether reducing poverty causes changes

而是真正探究在儿童三岁前，

in children's cognitive, emotional and brain development

减轻贫困能否引起

儿童的认知、情感 和大脑发育的改变，

in the first three years of life --

the very time when we believe

我们认为，这三年

the developing brain may be most malleable to experience.

发育中的大脑 最容易被不同的经历塑造。

Now, we won't have definitive results from this study for several years,

这项研究在几年之内 都不会有明确的结果，

但最起码

and if nothing else,

1,000 newborns and their moms will have a bit more cash each month

1000个新生儿和他们的 妈妈能在每个月

that they tell us they very much need.

拿到一些他们 迫切需要的额外的钱。

But what if it turns out that a cost-effective way

但如果研究证明， 给妈妈们更多钱

to help young children in poverty

是帮助在贫困中的孩子的

is to simply give their moms more money?

一种更加节省财力的方式呢？

If our hypotheses are borne out,

如果我们的假设被证实，

it's our hope that results from this work will inform debates about social services

那么我们希望这次实验的成果 能启发我们对社工服务的思考，

that have the potential to effect millions of families with young children.

这将有可能改变 几百万个有孩子的家庭。

Because while income may not be the only or even the most important factor

虽然收入并不是决定 儿童大脑发育的

in determining children's brain development,

唯一的或最重要的因素。

it may be one that,

从政策角度来说，

from a policy perspective,

它却有可能是

can be easily addressed.

最容易被解决的。

Put simply,

简单来说，

if we can show that reducing poverty changes how children's brains develop

如果我们能证明 减轻贫困能改变儿童大脑的发育，

and that leads to meaningful policy changes,

从而引起政策上的 有意义的改变，

then a young child born into poverty today

那么今天一个贫困家庭的孩子，

may have a much better shot at a brighter future.

就有可能有一个 更加美好的未来。

Thank you.

谢谢。

(Applause)

（鼓掌）