What I’m about to share with you
are findings from a study of the brains of more than 1,000 children and adolescents.
Now these were children who were recruited from diverse homes around the United States,
and this picture is an averageof all of their brains.
The front of this average brainis on your left
and the back of this average brainis on your right.
Now one of the things we were very interested in was the surface area of the cerebral cortex,
或者说 是表层的薄褶皱层 即大脑主要的认知区域
or the thin wrinkly layer on the outer surface of the brain that does most of the cognitive heavy lifting.
And that’s because past work by other scientists has suggested that in many cases,
a larger cortical surface area is often associated with higher intelligence.
Now in this study, we found one factor
that was associated with the cortical surface area across nearly the entire surface of the brain.
That factor was family income.
Now here, every point you see in color
is a point where higher family income was associated with a larger cortical surface area in that spot.
有些区域 用黄色显示的区域 联系尤其显著
And there were some regions, shown here in yellow, that association was particularly pronounced.
And those are regions that we know support a certain set of cognitive skills:
language skills like vocabulary and reading
as well as the ability to avoid distraction and exert self-control.
And that’s important, because those are the very skills
that children living in poverty are most likely to struggle with.
In fact, a child living with poverty is likely to perform worse on tests
of language and impulse control before they even turn two.
现在 关于这项研究 我要强调几点
Now , there are a few points I’d like to highlight about this study.
Number one: this link between family income and children’s brain structure
was strongest at the lowest income levels.
So that means that dollar for dollar, relatively small differences in family income
were associated with proportionately greater differences in brain structure
among the most disadvantaged families.
直观上来讲 这说得过去 不是吗？
And intuitively, that makes sense, right?
An extra 20,000 dollars for a family earning, say, 150,000 dollars a year
would certainly be nice, but probably not game-changing,
whereas an extra 20,000 dollars for a family only earning 20,000 dollars a year
would likely make a remarkable difference in their day-to-day lives.
Now the second point I’d like to highlight that
this link between family income and children’s brain structure didn’t depend on the children’s age,
it didn’t depend on their sex and it didn’t depend on their race or ethnicity.
And the final point — and this one’s key
there was tremendous variability from one child to the next,
by which I mean there were plenty of children from higher-income homes with smaller brain surfaces
and plenty of children from lower-income homes with larger brain surfaces.
这儿有个比较 我们都知道 童年时期男孩一般比女孩更高
Here’s an analogy. We all know that in childhood, boys tend to be taller than girls,
但走进小学教室 你会发现 一些女孩比男孩要高
but go into any elementary school classroom, and you’ll find some girls who are taller than some boys.
所以在贫困家庭长大 对拥有较小大脑皮层表面而言 是个显然的风险因素
So while growing up in poverty is certainly a risk factor for a smaller brain surface,
in no way can I know an individual child’s family income
and know with any accuracy what that particular child’s brain would look like.
I want you to imagine,for a moment, two children.
One is a young child born into poverty in America;
the other is also an American child, but one who was born into more fortunate circumstances.
出生时 我们发现 他们的大脑功能完全没有区别
Now, at birth, we find absolutely no differences in how their brains work.
But by the time those two kids are ready to start kindergarten,
we know that the child living in poverty is likely to have cognitive scores
that are on average 60 percent lower than those of the other child.
Later on, that child living in poverty will be five times more likely to drop out of high school,
and if she does graduate high school,
she’ll be less likely to earn a college degree.
By the time those two kidsare 35 years old,
if the first child spenther entire childhood living in poverty,
she is up to 75 times more likely to be poor herself.
But it doesn’t have to be that way.
As a neuroscientist, one of things I find most exciting about the human brain
is that our experiences change our brains.
现在 这个概念 被称作“神经可塑性”
Now,this concept, known as neuroplasticity,
就是说 这些孩子大脑结构的差异 并不能判定其一生都是平庸的
means that these differences in children’s brain structure don’t doom a child to a life of low achievement.
The brain is not destiny.
And if a child’s brain can be changed, then anything is possible.
现在 作为社会 我们每年花费数十亿美元来教育我们的孩子
Now,as a society, we spent billions of dollars each year educating our children.
So what can we tell schools, teachers and parents who want to help support kids
from disadvantaged backgrounds to do their best in school and in life?
Well, emerging science suggests that growing up in poverty is associated with a host of different experiences
and that these experiences in turn may work together to help shape brain development and ultimately help kids learn.
And so if this is right,
begs the question: Where along this pathway can we step in and provide help?
So let’s consider first intervening at the level of learning itself
–most commonly throughschool-based initiatives.
Now, should we be encouraging teachers to focus on the kinds of skills
that disadvantaged kidsare most likely to struggle with?
Of course. The importance of high-quality education based in scientific evidence really can’t be overstated.
And there are a number of examples of excellent interventions targeting things like literacy or self-regulation
that do in fact improve kids’ cognitive development and their test scores.
But as any intervention scientistdoing this work would tell you,
这个工作很有挑战性 很难执行高质量 基于证据的教育
this work is challenging. It’s hard to implement high-quality,evidence-based education.
And it can be labor-intensive, it’s sometimes costly.
And in many cases,
these disparities in child development emerge early —
well before the startof formal schooling —
sometimes when kids are just toddlers.
And so I would argue:
school is very important,
but if we’re focusing all of our policy efforts
on formal schooling, we’re probably starting too late.
So what about taking a step back
and focusing on trying to changechildren’s experiences?
What particular experiences are associated with growing up in poverty
and might be able to be targetedto promote brain development
and learning outcomes for kids?
当然 方法有很多 不是吗？
Of course, there are many, right?
比如 营养方面 医疗保健
Nutrition,access to health care,
exposure to second-hand smoke or lead,
experience of stress or discrimination, to name a few.
In my laboratory,
we’re particularly focused on a few types of experiences
that we believe may be able to be targeted
to promote children’s brain development
and ultimately improvetheir learning outcomes.
As one example,
take something I’ll call the home language environment
by which I mean,
we know that the number of words kids hear
and the number of conversationsthey’re engaged in every day
can vary tremendously.
By some estimates, kids from more advantaged backgrounds
hear an average of 30 millionmore spoken words
in the first few years of life
compared to kids from less advantaged backgrounds.
Now,in our work,
we’re finding that kids who experience more back-and-forth,
responsive conversational turns
tend to have a larger brain surface in parts of the brain
that we know are responsiblefor language and reading skills.
And in fact, the numberof conversations they hear
seems to matter a little bit more than the sheer number
of words they hear.
So one tantalizing possibility is that we should be teaching
parents not just to talk a lot,
but to actually have more conversations with their children.
In this way,it’s possiblethat we’ll promote brain development
and perhaps their kids’ languageand reading skills.
And in fact, a numberof scientists are testing
that exciting possibility right now.
But of course, we all know
that growing up in poverty is associated with lots of different experiences
beyond just how manyconversations kids are having.
So how do we choose what else to focus on?
The list can be overwhelming.
There are a number of high-quality interventions
that do try to changechildren’s experience,
many of which are quite effective.
但是 正如基于学校提出的提议一样 这项工作很难
But again,just like school-based initiatives, this is hard work.
It can be challenging,
it can be labor-intensive, sometimes costly…
and on occasion,
it can be somewhat patronizing for scientists to swoop in
and tell a family what they need to change
in order for their child to succeed.
So I want to share an idea with you.
What if we tried to helpyoung children in poverty
by simply givingtheir families more money?
I’m privileged to be workingwith a team of economists,
social policy experts and neuroscientists
in leading Baby’s First Years,
the first-ever randomized study
to test whether poverty reduction
causes changes in children’s brain development.
Now,the ambition of the study is large,
but the premise is actually quite simple.
In May of 2018,
we began recruiting 1,000 mothers living below the federal poverty line
shortly after they gave birthin a number of American hospitals.
Upon enrolling in our study,
all mothers receive an unconditional monthly cash gift
for the first 40 monthsof their children’s lives,
and they’re free to use this moneyhowever they like.
But importantly,mothers are being randomized,
so some mothers are randomized to
receive a nominal monthly cash gift
and others are randomized to receive several hundred dollars each month,
an amount that we believe is large enough
to make a difference in their day-to-day lives, in most cases
increasing their monthly income by 20 to 25 percent.
So in this way,
we’re hoping to finally move past questions
of how poverty is correlatedwith child development
and actually be able to test whether reducing poverty causes changes
in children’s cognitive, emotionaland brain development
in the first three years of life —
the very time when we believe the developing brain
may be most malleable to experience.
Now,we won’t have definitive results
from this study for several years,
and if nothing else,
1,000 newborns and their moms
will have a bit more cash each month
that they tell us they very much need.
But what if it turns out that a cost-effective way
to help young children in poverty
is to simply give their moms more money?
If our hypotheses are borne out, it’s our hope
that results from this work will inform debates about social services
that have the potential to effect millions of families with young children.
Because while income may not be
the only or even the most important factor
in determining children’sbrain development,
it may be one that, from a policy perspective,
can be easily addressed.
Put simply, if we can show
that reducing poverty changes how children’s brains develop
and that leads to meaningfulpolicy changes,
then a young child born into poverty today
may have a much better shotat a brighter future.
Thank you. [Applause]