How your brain decides what is beautiful | Anjan Chatterjee

翻译人员: JieWei Li 校对人员: Jing Peng

It's 1878.

那是在1878年，

Sir Francis Galton gives a remarkable talk.

弗朗西斯 · 盖尔顿先生

He's speaking to the anthropologic institute of Great Britain and Ireland.

在英国和爱尔兰皇家人类学研究所 做了一个震惊四座的演讲。

Known for his pioneering work in human intelligence,

他因在人类智慧方面的 开创性工作而闻名，

Galton is a brilliant polymath.

盖尔顿是一个杰出的博学家。

He's an explorer,

他是个开拓者，

an anthropologist,

人类学家，

a sociologist,

社会学家，

a psychologist

心理学家

and a statistician.

和统计学家。

He's also a eugenist.

同时他也是一位优生学家。

In this talk,

在这个演讲当中，

he presents a new technique by which he can combine photographs

他展示了一个可以结合照片

and produce composite portraits.

来生成组合肖像的新技术。

This technique could be used to characterize different types of people.

这项技术可以被用来区分不同人种。

Galton thinks that if he combines photographs of violent criminals,

盖尔顿认为，如果 让他对凶犯的照片进行组合，

he will discover the face of criminality.

他就会揭开犯罪的真面目。

但令他吃惊的是，

But to his surprise,

the composite portrait that he produces

组合出来的肖像

is beautiful.

面容十分俊朗。

Galton's surprising finding raises deep questions:

盖尔顿惊人的发现产生了 一个令人回味的问题：

What is beauty?

什么是美？

Why do certain configurations of line and color and form excite us so?

为什么一些独特线条，颜色和形状的 组合激发了我们的兴趣？

For most of human history,

在茫茫的人类历史中，

these questions have been approached using logic and speculation.

人们尝试着用逻辑和猜测 来解答这些问题。

But in the last few decades,

但在过去的几十年里，

scientists have addressed the question of beauty

科学家们利用进化心理学 和神经科学

using ideas from evolutionary psychology and tools of neuroscience.

作为工具，解答了“美”的问题。

We're beginning to glimpse the why and the how of beauty,

我们开始窥探美丽背后的原因，

at least in terms of what it means for the human face and form.

至少是在人类的 脸部和体型的范畴内。

And in the process,

在这个过程之中，

we're stumbling upon some surprises.

一些发现让我们感到很惊喜。

When it comes to seeing beauty in each other,

谈到发现彼此的美时，

while this decision is certainly subjective for the individual,

这样的决定对所有人 而言都是主观的，

it's sculpted by factors that contribute to the survival of the group.

是由有助于群体生存的 因素塑造而成的。

Many experiments have shown

很多研究都显示了

that a few basic parameters contribute to what makes a face attractive.

存在一些基本常数， 使得一张脸具有吸引力。

These include averaging, symmetry and the effects of hormones.

其中包括均衡，对称 和荷尔蒙的效应。

Let's take each one of these in turn.

让我们来分别说说每个因素。

Galton's finding

盖尔顿发现

that composite or average faces are typically more attractive

组合的或者均衡过的面孔，

than each individual face that contributes to the average

一般会比单一的面孔更加吸引人，

has been replicated many times.

因为它们被复制了许多次。

This laboratory finding fits with many people's intuitions.

这项实验的发现 印证了许多人的直觉。

Average faces represent the central tendencies of a group.

平均化的脸代表了 一个群体的中心倾向。

People with mixed features represent different populations,

有混合特征的人 代表着不同种类的人群，

and presumably harbor greater genetic diversity

可能拥有了更大的遗传多样性，

and adaptability to the environment.

也能更好的适应环境。

Many people find mixed-race individuals attractive

很多人发现混血的人 更加具有吸引力，

and inbred families less so.

而近交系家庭则反之。

The second factor that contributes to beauty is symmetry.

第二个促成美的因素是对称性。

People generally find symmetric faces more attractive than asymmetric ones.

人们通常发现对称的脸 要比非对称的好看。

Developmental abnormalities are often associated with asymmetries.

异常的发育经常会与非对称有关。

And in plants, animals and humans,

在植物，动物和人类身上，

asymmetries often arise from parasitic infections.

非对称性一般来自于寄生虫感染。

Symmetry, it turns out,

事实证明，

is also an indicator of health.

对称也是一种健康的标志。

In the 1930s,

在20世纪30年代，

a man named Maksymilian Faktorowicz

一个叫做马思琦米兰 · 法克罗奇司的人 （Maksymilian Faktorowicz）

recognized the importance of symmetry for beauty

在设计美容千分尺时

when he designed the beauty micrometer.

发现了对称美的重要性。

With this device,

利用这种设备，

he could measure minor asymmetric flaws

他可以检测到一些

which he could then make up for with products he sold from his company,

较小的非对称瑕疵， 然后使用他自己公司的产品

named brilliantly after himself, Max Factor,

弥补这些瑕疵， 这家以他的名字命名的公司，

which, as you know, is one of the world's most famous brands

就是现今世界上 最有名的美妆品牌之一

for "make up."

“蜜丝佛陀（Max Factor）”。

The third factor that contributes to facial attractiveness

第三个使脸部有吸引力的因素是

is the effect of hormones.

荷尔蒙的效果。

And here, I need to apologize for confining my comments

在这个演讲中，评论只局限于异性恋，

to heterosexual norms.

对此我表示歉意。

But estrogen and testosterone play important roles

但是雌性激素和睾丸酮 确实在塑造我们认为

in shaping features that we find attractive.

有吸引力的特征方面 发挥了重要作用。

Estrogen produces features that signal fertility.

雌性激素促成了与生育力有关的特质。

Men typically find women attractive

男性通常会觉得

who have elements of both youth and maturity.

年轻且成熟的女性更有吸引力。

A face that's too baby-like might mean that the girl is not yet fertile,

一个长着娃娃脸的女孩 可能意味着生育力不强，

so men find women attractive

所以男性会觉得

who have large eyes, full lips and narrow chins

大眼睛，厚嘴唇和尖下巴 像是年轻的迹象，

as indicators of youth,

这样的女性会更有吸引力，

and high cheekbones as an indicator of maturity.

同时，高颧骨也象征着成熟。

Testosterone produces features that we regard as typically masculine.

睾丸酮则产生了男性化的特质。

These include heavier brows,

这包括更重的眉毛，

thinner cheeks

更尖的脸颊，

and bigger, squared-off jaws.

更大的，方形的下巴。

But here's a fascinating irony.

但是这里存在一个有趣的讽刺。

In many species,

在许多的物种当中，

if anything,

恰恰相反，

testosterone suppresses the immune system.

睾丸酮会抑制免疫系统。

So the idea that testosterone-infused features are a fitness indicator

所以关于睾丸酮旺盛 是一种健康迹象的说法

doesn't really make a whole lot of sense.

在总体上就没有什么意义了。

Here, the logic is turned on its head.

在这一点上，逻辑开始发挥作用了。

Instead of a fitness indicator,

科学家利用障碍性原则，

scientists invoke a handicap principle.

取代了健康的迹象。

The most commonly cited example of a handicap

最常被引用的障碍性的例子，

is the peacock's tail.

是雄孔雀的尾巴。

This beautiful but cumbersome tail doesn't exactly help the peacock

这个既美丽又笨重的尾巴

avoid predators

并不会帮助孔雀躲避天敌，

and approach peahens.

或者去接近雌孔雀。

Why should such an extravagant appendage evolve?

为什么孔雀会进化出 如此奢侈的附肢出来呢？

Even Charles Darwin,

就连查尔斯 · 达尔文

in an 1860 letter to Asa Gray wrote

都在1860年写给 阿萨 · 格雷的信中提到，

that the sight of the peacock's tail made him physically ill.

一见孔雀尾巴就让他开始抱恙。

He couldn't explain it with his theory of natural selection,

他不能用自然选择的理论去解释，

and out of this frustration,

在沮丧之外，

he developed the theory of sexual selection.

他还创建了一种理论， 叫做性别选择。

On this account,

在这个基础上来理解，

the display of the peacock's tail is about sexual enticement,

孔雀展示它们的尾巴是一种性诱惑，

and this enticement means it's more likely the peacock will mate

这种诱惑的手段会使 雄孔雀有更高的几率去交配，

and have offspring.

然后拥有后代。

Now, the modern twist on this display argument

目前， 有新的研究显示，

is that the peacock is also advertising its health to the peahen.

雄孔雀是在对雌孔雀 展示自己的健康状况。

Only especially fit organisms can afford to divert resources

只有特别健康的生物才有能力

to maintaining such an extravagant appendage.

去维持如此夸张的附肢。

Only especially fit men can afford the price that testosterone levies

在免疫系统当中， 只有非常健康的男性

on their immune system.

才能维持睾丸酮的水准。

And by analogy, think of the fact

做个比喻，想想一下

that only very rich men can afford to pay more than $10,000 for a watch

只有非常富有的男性才可以 买得起超过一万美金一块的手表

as a display of their financial fitness.

来展现他们在经济上的富有。

Now, many people hear these kinds of evolutionary claims

许多人听说了这种进化观点，

and think they mean that we somehow are unconsciously seeking mates

认为我们其实是在通过潜意识

who are healthy.

寻找健康的伴侣。

And I think this idea is probably not right.

但是我觉得这个观点也许并不正确。

Teenagers and young adults are not exactly known for making decisions

年轻人择偶时并不知道

that are predicated on health concerns.

如何对健康做出判断。

But they don't have to be,

但是他们并不需要那么做，

and let me explain why.

让我解释一下为什么。

Imagine a population

想象有一群人，

in which people have three different kinds of preferences:

他们有三种不同的偏好：

for green, for orange and for red.

绿色，橙色和红色。

From their point of view,

在他们的观点里，

these preferences have nothing to do with health;

这些偏好跟健康没有一点关联；

they just like what they like.

他们只是喜欢他们所喜欢的。

But if it were also the case that these preferences are associated

不过如果这些偏好跟

with the different likelihood of producing offspring --

繁衍的后代有关——

let's say in a ratio of 3:2:1 --

比如在一个3：2：1的比例中——

then in the first generation,

在第一代里，

there would be 3 greens to 2 oranges to 1 red,

会有三个喜欢绿色， 两个喜欢橙色，一个喜欢红色，

and in each subsequent generation,

在后续的每一代当中，

the proportion of greens increase,

绿色的比例在不断上升，

so that in 10 generations,

到了第十代，

98 percent of this population has a green preference.

百分之九十八的人会更喜欢绿色。

Now, a scientist coming in and sampling this population

现在，一个科学家 对这些人进行抽样调查，

discovers that green preferences are universal.

发现对绿色的偏爱已经非常普遍了。

So the point about this little abstract example

所以从这个有点抽象的例子 我们可以发现，

is that while preferences for specific physical features

对于某种物理特征的偏好

can be arbitrary for the individual,

如果具有遗传性，

if those features are heritable

那就会被传递到个人身上，

并且它们跟生殖优势有关。

and they are associated with a reproductive advantage,

over time,

随着时间的推移，

they become universal for the group.

这些特征就会成为 某一群体的共性。

So what happens in the brain when we see beautiful people?

所以，当我们看到高颜值的人时， 我们的大脑里发生了什么？

Attractive faces activate parts of our visual cortex

有吸引力的脸会刺激大脑后部

in the back of the brain,

一部分视觉皮质中

an area called the fusiform gyrus,

一个叫梭状回的区域，

that is especially tuned to processing faces,

主要是用来审示面容的，

and an adjacent area called the lateral occipital complex,

相邻的区域称为侧枕叶,

that is especially attuned to processing objects.

是用来审阅目标的。

In addition,

此外，

attractive faces activate parts of our reward and pleasure centers

吸引人的脸庞激活了 我们大脑前部深处的

in the front and deep in the brain,

奖赏和娱乐中心部位，

and these include areas that have complicated names,

其中包括一些复杂的区域名称，

like the ventral striatum,

比如腹侧纹状体，

the orbitofrontal cortex

眶额叶皮层，

and the ventromedial prefrontal cortex.

和腹内侧前额叶皮层。

Our visual brain that is tuned to processing faces

我们的视觉大脑在审阅脸部时

interacts with our pleasure centers

与监管愉悦的中枢相呼应，

to underpin the experience of beauty.

从而加强了对美的感受。

Amazingly, while we all engage with beauty,

令人惊讶的是，当我们 在与美进行交流时，

without our knowledge,

在毫无意识的情况下，

beauty also engages us.

美也在与我们进行互动。

Our brains respond to attractive faces

即便我们没有注意，

even when we're not thinking about beauty.

我们的大脑会也会对 有吸引力的脸部产生反应。

We conducted an experiment in which people saw a series of faces,

我们进行了一个实验， 人们观察一系列的脸

and in one condition,

并遵循一个条件，

they had to decide if a pair of faces were the same or a different person.

他们要比较一对面孔， 判断是否是同一个人。

Even in this condition,

甚至在这种情况下，

attractive faces drove neural activity robustly in their visual cortex,

迷人的面孔也会使 他们的视觉皮层神经活动强烈，

despite the fact that they were thinking about a person's identity

尽管他们正在思考一个人的身份，

and not their beauty.

而不是他们的美貌。

Another group similarly found automatic responses to beauty

对另外一组人的测试表明， 他们的愉悦中枢

within our pleasure centers.

同样对美自动产生了反应。

Taken together, these studies suggest

综合起来，这些研究表明

that our brain automatically responds to beauty

结合视觉与愉悦，

by linking vision and pleasure.

我们的大脑会自动对美作出反应。

These beauty detectors, it seems,

当我们看见美丽的东西时，

ping every time we see beauty,

这些美的探测器就会发出信号，

regardless of whatever else we might be thinking.

跟我们在想什么无关。

We also have a "beauty is good" stereotype embedded in the brain.

还有一种“美即是好”的 传统刻在我们的脑海中。

Within the orbitofrontal cortex,

在眼窝前额皮层内，

there's overlapping neural activity

有重叠的神经活动

in response to beauty and to goodness,

对美丽与善良做出反应，

当人们没有明确地 思考美丽或善良时，

and this happens even when people aren't explicitly thinking

about beauty or goodness.

这种反应也会发生。

Our brains seem to reflexively associate beauty and good.

我们的大脑好像会 自动把美与善对应起来。

And this reflexive association may be the biologic trigger

而且这种反射可能是

for the many social effects of beauty.

关于对“美”诸多误解的生物触发器。

Attractive people receive all kinds of advantages in life.

吸引力强的人一生都会 受到各种各样的厚待。

They're regarded as more intelligent,

他们会被认为更加聪明，

more trustworthy,

更加值得信任，

they're given higher pay and lesser punishments,

甚至会得到更高的工资 和更少的惩罚，

even when such judgments are not warranted.

即使这种判断是毫无根据的。

These kinds of observations reveal beauty's ugly side.

这些发现揭露了美的 丑陋的那一面。

In my lab, we recently found

我的实验室

that people with minor facial anomalies and disfigurements

最近发现了脸部有缺陷的人

are regarded as less good, less kind,

会被认为没有那么好，那么的善良，

less intelligent, less competent and less hardworking.

没那么聪明和有能力， 也没那么努力。

Unfortunately, we also have a "disfigured is bad" stereotype.

不幸的是，我们都有一个 “丑即是恶”的刻板印象。

This stereotype is probably exploited and magnified

由于大众媒体的传播， 这个刻板印象可能

by images in popular media,

被利用且放大了，

in which facial disfigurement is often used as a shorthand

其中面部的丑陋 通常被作为一种象征，

to depict someone of villainous character.

来刻画反面人物。

We need to understand these kinds of implicit biases

我们需要去理解这些隐晦的偏见，

if we are to overcome them

如果我们想要去克服它们，

and aim for a society in which we treat people fairly,

并致力于发展一个人人平等的社会，

based on their behavior and not on the happenstance of their looks.

以人们的行为为基础，而不是以貌取人。

Let me leave you with one final thought.

我想给大家留下一个最后的思考。

Beauty is a work in progress.

美是一种进步的产物。

The so-called universal attributes of beauty

所谓美的普遍特质，

were selected for during the almost two million years of the Pleistocene.

是在更新世近二百万年的 时期中被选定的。

Life was nasty, brutish and a very long time ago.

很久之前的生命是肮脏的，野蛮的。

The selection criteria for reproductive success from that time

当时的生育存活率的选择标准

doesn't really apply today.

现在已经不再适用了。

For example,

举个例子，

death by parasite is not one of the top ways that people die,

死于寄生虫病并不是 现在最常见的死因，

at least not in the technologically developed world.

至少不是在科技发达的国家。

From antibiotics to surgery,

从抗生素到手术，

birth control to in vitro fertilization,

计划生育到人工授精，

the filters for reproductive success are being relaxed.

繁殖成效的筛选标准被放宽了。

And under these relaxed conditions,

在放宽的情况之下，

preference and trait combinations are free to drift

偏好与特质的组合可以随意发生转移，

and become more variable.

更加可变。

Even as we are profoundly affecting our environment,

即使我们在深深地影响我们的环境，

modern medicine and technological innovation

现代医药和技术革新

is profoundly affecting

在深刻的影响

the very essence of what it means to look beautiful.

美丽本质的意义。

The universal nature of beauty is changing

当我们正在改变世界的时候，

even as we're changing the universe.

美的普遍特质也正在改变。

Thank you.

谢谢。

(Applause)

（掌声）