the optimism bias. It's a cognitive illusion that we've been studying in my lab for the past few years

樂觀偏見。 這是個認知錯覺 過去數年來一直在我的實驗室裏研究著

and 80 percent of us have it.

我們之中有80%都得過

It's our tendency to overestimate our likelihood of experiencing good events in our lives

我們容易高估 可能是因為生活中所經歷的都是好事

and underestimate our likelihood of experiencing bad events

卻低估了可能也會經歷到壞事

So we underestimate our likelihood of suffering from cancer, being in a car accident

所以我們低估了可能也會患有癌症 可能也會出車禍

We overestimate our longevity, our career prospects.

我們高估了壽命、職涯前景

In short, we're more optimistic than realistic, but we are oblivious to the fact.

簡言之，我們是樂觀多於實際 但是我們都忽略了一個事實

Take marriage for example. In the Western world, divorce rates are about 40 percent.

就拿婚姻來說 離婚率在西方世界大約是40%

That means that out of five married couples, two will end up splitting their assets

也就是說五對已婚夫妻中 有兩對會玩完了然後分財產

But when you ask newlyweds about their own likelihood of divorce, they estimate it at zero percent

但是當你問新婚夫妻他們本身的離婚可能性時 他們都說百分之百的不可能

And even divorce lawyers, who should really know better

甚至連離婚律師，應該是最了解情況的人

hugely underestimate their own likelihood of divorce.

也是大大地低估了他們自己離婚的可能性

So it turns out that optimists are not less likely to divorce

所以結論就是樂觀者不是不可能離婚

but they are more likely to remarry.

而是較可能再婚

In the words of Samuel Johnson, "Remarriage is the triumph of hope over experience."

塞謬耳‧約翰曾說過， “再婚是希望對經歷的勝利。”

So if we're married, we're more likely to have kids.

所以如果我們結了婚，就比較可能有小孩

And we all think our kids will be especially talented.

而且都會認為我們的小孩特別聰明

This, by the way, is my two-year-old nephew, Guy

這一位，順便一提，是我的兩歲外甥，蓋

And I just want to make it absolutely clear that he's a really bad example of the optimism bias

我想說的只是 他真的是樂觀偏見的壞榜樣

because he is in fact uniquely talented.

因為他真的是絕頂聰明

And I'm not alone. Out of four British people,

而且不是只有我這麼認為，在四個英國人中

three said that they were optimistic about the future of their own families. That's 75 percent.

三個會說 他們對於自己家人的前途都相當樂觀 這樣的比例有75%

But only 30 percent said that they thought families in general are doing better than a few generations ago.

但只有30%的人說 他們認為一般說來家人 做得比前幾代要好

And this is a really important point, because we're optimistic about ourselves

這真的是很重要的一點， 因為我們對自己樂觀

we're optimistic about our kids, we're optimistic about our families

我們對孩子樂觀， 對我們的家人樂觀

but we're not so optimistic about the guy sitting next to us,

我們旁邊的人卻不是那麼樂觀

and we're somewhat pessimistic about the fate of our fellow citizens and the fate of our country

反而有些悲觀 對我們的市民朋友的命運及國家的命運

But private optimism about our own personal future remains persistent.

但是對於我們個人前途的私人樂觀 仍然持續

And it doesn't mean that we think things will magically turn out okay

這並不是說我們認為事情會奇蹟般的變好

but rather that we have the unique ability to make it so.

而是我們有獨特的能力使它變好

Now I'm a scientist, I do experiments. So to show you what I mean

現在，我是個科學家，我來做個實驗。 讓你們更了解我的意思

I'm going to do an experiment here with you. Okay.

我在這裏要和你們一起做個實驗

So I'm going to give you a list of abilities and characteristics,

我打算列出一張能力和特性的清單

and I want you to think for each of these abilities where you stand relative to the rest of the population.

我要你們想想看這些每個能力 你所在的水準與其它人相比

The first one is getting along well with others. Who here believes they're at the bottom 25 percent?

第一個是和他人相處得很好 在座各位有誰相信自己是最底部的25%？

Okay, that's about 10 people out of 1,500. Who believes they're at the top 25 percent?

好吧，那大概是1,500人中的10個 有誰相信自己是最頂端的25%?

That's most of us here. Okay, now do the same for your driving ability.

這裏大部份人都相信。 好。 相同問題評估你自己的駕駛能力

How interesting are you? How attractive are you?

你這個人有多有趣? 你有多少吸引力?

How honest are you? And finally, how modest are you?

你有多誠實? 最後，你有多謙虛?

So most of us put ourselves above average on most of these abilities.

所以大部份的人把自己放在水平之上

Now this is statistically impossible. We can't all be better than everyone else.

這是完全不可能的，我們不可能每個人都比別人好

But if we believe we're better than the other guy,

但是如果我們相信自己比他人好

well that means that we're more likely to get that promotion, to remain married,

就是說我們容易高升、容易維持婚姻

because we're more social, more interesting.

因為我們較社會化、較有趣

And it's a global phenomenon. The optimism bias has been observed in many different countries

這是個全球化的現象 樂觀偏見在不同的國家裡都被注意到了

in Western cultures, in non-Western cultures

在西方文化裏、在非西方文化裏

in females and males, in kids, in the elderly. It's quite widespread.

在女性與男性之間 在小孩和年長者之間 分佈甚廣

But the question is, is it good for us? So some people say no

但問題是，對我們而言好嗎? 有些人說不好

Some people say the secret to happiness is low expectations

有些人說幸福的秘訣 就是降低期待值

I think the logic goes something like this: If we don't expect greatness,

我想邏輯是這樣的：如果我們的期盼不高

if we don't expect to find love and be healthy and successful,

如果我們不期盼找到愛、身體健康和事業成功

well we're not going to be disappointed when these things don't happen.

當這些事都沒發生時，我們就不會失望

And if we're not disappointed when good things don't happen, and we're pleasantly surprised when they do, we will be happy.

而且，就算好事沒發生時，我們也不會失望 如果發生了好事，就算給我們一個大驚喜 我們會很快樂

So it's a very good theory, but it turns out to be wrong for three reasons

所以這是個相當好的推論， 但是有三個理由讓它變成錯的

Number one: Whatever happens, whether you succeed or you fail, people with high expectations always feel better.

第一：不論發生什麼事，不管你成功還是失敗， 期待高的人通常都會自我感覺較好。

Because how we feel when we get dumped or win employee of the month depends on how we interpret that event.

因為，我們被人拋棄或當上明星店員的感覺如何， 完全看我們怎麼解釋那件事而定

The psychologists Margaret Marshall and John Brown studied students with high and low expectations.

心理學家Margraret Marshall 及 John Brown 研究期盼高及期盼低的學生

And they found that when people with high expectations succeed, they attribute that success to their own traits.

他發現期待高的人成功時， 他們將成功歸功於自己的人格特質

I'm a genius, therefore I got an A, therefore I'll get an A again and again in the future

我是個天才，所以我得個A， 所以以後我也會一再得A

When they failed, it wasn't because they were dumb, but because the exam just happened to be unfair.

當他們失敗時，不是因為他們笨。 而是因為這個考試剛巧不公平

Next time they will do better. People with low expectations do the opposite.

下一次他們會考得更好。 期盼低的人剛好相反

So when they failed it was because they were dumb

所以當他們失敗時他們就是笨

and when they succeeded it was because the exam just happened to be really easy. Next time reality would catch up with them. So they felt worse.

而當他們成功時， 是因為考試剛巧真的太簡單， 下一次就會露出馬腳了。 所以他們覺得自己很糟糕。

Number two: Regardless of the outcome, the pure act of anticipation makes us happy.

第二：不管結果， 單純的期待行為使我們快樂

The behavioral economist George Lowenstein asked students in his university to imagine getting a passionate kiss from a celebrity

行為經濟學家George Lowenstein 在大學裏問學生得到想要得到哪個名人的熱吻

any celebrity.

任何名人

Then he said, "How much are you willing to pay to get a kiss from a celebrity if the kiss was delivered immediately

他說：“你願付多少錢 得到名人的吻，如果吻馬上就來

in three hours, in 24 hours, in three days, in one year, in 10 years?

3小時內，24小時內，3天內， 1年內，10年內？

He found that the students were willing to pay the most not to get a kiss immediately, but to get a kiss in three days

他發現學生最願意付的是 不要馬上就能得到的吻而是3天內能得到的吻

they were willing to pay extra in order to wait

他們願意支付額外費用來等待一個吻

Now they weren't willing to wait a year or 10 years; no one wants an aging celebrity

但他們不願意一等就等個1年或10年的； 因為沒人會要個上了年紀的明星

But three days seemed to be the optimum amount.

但是三天似乎是最佳的天數

So why is that? Well if you get the kiss now, it's over and done with

為什麼會這樣? 嗯。如果你現在馬上就被親一下，那馬上就沒了

But if you get the kiss in three days, well that's three days of jittery anticipation, the thrill of the wait.

但是如果你三天內才被親 那就有三天緊張的預期，等待的快感

The students wanted that time to imagine where is it going to happen, how is it going to happen.

學生需要那些時間來想像即將要發生的事情，會在哪裡發生、怎麼發生的。

Anticipation made them happy.

期待使他們快樂。

This is, by the way, why people prefer Friday to Sunday

順道一提的，這也就是為何人們比週日還喜歡週五

It's a really curious fact, because Friday is a day of work and Sunday is a day of pleasure,

這真是讓人難以理解的事實， 因為週五是個工作天而週日是個歡樂天

so you'd assume that people will prefer Sunday, but they don't.

所以可以假設人們較喜歡星期天， 但不是

It's not because they really, really like being in the office and they can't stand strolling in the park or having a lazy brunch.

不是因為他們真的、真的愛呆在辦公室 也不是因為他們不能忍受在公園裏散步 或是不想吃個慵懶的早午餐

We know that, because when you ask people about their ultimate favorite day of the week,

我們知道，因為當你問人 一週中最喜歡哪一天

surprise, surprise, Saturday comes in at first, then Friday, then Sunday. People prefer Friday because Friday brings with it the anticipation of the weekend ahead

驚訝吧，驚訝吧，週六是首選， 之後是週五，再來才是週日， 人們喜歡週五 因為週五為週末帶來期待

all the plans that you have. On Sunday, the only thing you can look forward to is the work week.

期待所有的計劃 但在週日，唯一能企望到的 就是整週的工作

So optimists are people who expect more kisses in their future, more strolls in the park.

所以樂觀者就是期待未來能有更多吻的人或是在公園的散步

And that anticipation enhances their wellbeing

期待提高了他們的幸福感

In fact, without the optimism bias, we would all be slightly depressed. People with mild depression, they don't have a bias when they look into the future

事實上，沒有了樂觀偏見 我們都會有一點點沮喪。輕度憂鬱症患者就對於他們的未來沒有任何偏見

They're actually more realistic than healthy individuals.

實際上，他們比健康的人更現實

But individuals with severe depression, they have a pessimistic bias.

但是重度憂鬱症患者 他們有悲觀的偏見

So they tend to expect the future to be worse than it ends up being.

所以往往盼望的未來，往往比生命結束還要悲慘

So optimism changes subjective reality. The way we expect the world to be changes the way we see it.

所以樂觀改變了主觀的現實 我們期盼世界變成我們眼見的方式

But it also changes objective reality. It acts as a self-fulfilling prophecy.

但是也改變了客觀存在 它表現得像個自我實現的預言

. And that is the third reason why lowering your expectations will not make you happy.

第三個理由 為什麼降低期待不會使你感到快樂

Controlled experiments have shown that optimism is not only related to success

對照實驗顯示 樂觀不只和成功有關，樂觀導向成功

it leads to success. Optimism leads to success in academia and sports and politics.

樂觀在學術界及運動界和政治界導向成功

And maybe the most surprising benefit of optimism is health. If we expect the future to be bright, stress and anxiety are reduced.

樂觀最令人驚喜的好處就是健康。如果我們期盼前途是光明的，壓力及焦慮會降低

So all in all, optimism has lots of benefits.

總而言之，樂觀有很多好處

But the question that was really confusing to me was, how do we maintain optimism in the face of reality?

但是真正困擾我的問題是 我們如何在現實面前保持樂觀?

As an neuroscientist, this was especially confusing, because according to all the theories out there

身為一個神經科學家，感到特別的困擾， 因為根據那裏所有的理論

when your expectations are not met, you should alter them.

期待未實現時，就應該改變他們

But this is not what we find

但這不是我們所發現的

We asked people to come into our lab in order to try and figure out what was going on.

我們要求人們來到實驗室 為的是嘗試而且弄清楚倒底是怎麼一回事

We asked them to estimate their likelihood of experiencing different terrible events in their lives

我們要求他們評估自己 經歷生活中不同悲劇經歷的可能性

So, for example, what is your likelihood of suffering from cancer?

例如，得癌症的可能性有多少?

And then we told them the average likelihood of someone like them to suffer these misfortunes.

之後我們告訴他們像他們這樣的人 遭受這些不幸的平均可能性

So cancer, for example, is about 30 percent. And then we asked them again, "How likely are you to suffer from cancer?"

癌症，舉例來說，大約30% 之後我們再問他們一次， “得癌症的可能性有多大？”

What we wanted to know was whether people will take the information that we gave them to change their beliefs.

我們想知道的是 人們是否會採信我們給的消息 來改變他們的看法

And indeed they did -- but mostly when the information we gave them was better than what they expected.

他們真的會 但大部份是在我們給他們的消息 比他們期待的消息還要好的時候

So for example, if someone said, "My likelihood of suffering from cancer is about 50 percent,"

舉例來說 如果某人說，“我得癌症的可能性 大概是50%

and we said, "Hey, good news. The average likelihood is only 30 percent," the next time around they would say

我們會說，“嘿，好消息。 平均可能性只有30%，” 下一次大概他們就會說，

Well maybe my likelihood is about 35 percent." So they learned quickly and efficiently.

“嗯，我的可能性大約是35%，” 所以他們學得很快也很有效率

But if someone started off saying, "My average likelihood of suffering from cancer is about 10 percent,"

但是如果有人開始說 “我得癌的一般可能性大約是10%

and we said, "Hey, bad news. The average likelihood is about 30 percent," the next time around they would say

我們就會說“嗨，壞消息。 一般得病的可能性是30% 到了下一輪的問題，他們會說

Yep. Still think it's about 11 percent

是，我仍然認為大約是11%

So it's not that they didn't learn at all -- they did

所以不是他們完全不知道--他們知道

but much, much less than when we gave them positive information about the future

但是比我們告訴他們的 有關未來的正面信息要少很多

And it's not that they didn't remember the numbers that we gave them;

也不是他們不記得我們給他們的數字

everyone remembers that the average likelihood of cancer is about 30 percent and the average likelihood of divorce is about 40 percent

每個人都記得癌症的平均可能性 大約是30% 而離婚的平均可能性大約是40%

But they didn't think that those numbers were related to them.

但是他們覺得這些數字跟他們無關

What this means is that warning signs such as these may only have limited impact

這表示像這樣的警告跡象 影響也有限

Yes, smoking kills, but mostly it kills the other guy.

是的，吸煙殺人，但是大部份是殺了別人

What I wanted to know was what was going on inside the human brain that prevented us from taking these warning signs personally

我想知道的是，人類腦袋到底發生了什麼事，才會讓我們以為這些警告跡象不是衝著我們來的

. But at the same time, when we hear that the housing market is hopeful, we think

但是同時當我們聽到房市很有希望的時候 我們就會想

Oh, my house is definitely going to double in price

喔，我的房子絕對漲了兩倍

To try and figure that out, I asked the participants in the experiment to lie in a brain imaging scanner

試著找出來 我要求實驗室裏的參與者 躺在腦成像掃描儀裏

It looks like this. And using a method called functional MRI

看起來就像這樣 而且用一種叫做核磁共振的儀器

we were able to identify regions in the brain that were responding to positive information.

我們可以辨認出腦中的哪些部位 回應了正面信息

One of these regions is called the left inferior frontal gyrus

其中一個部份被稱為左前下腦回

So if someone said, "My likelihood of suffering from cancer is 50 percent

所以如果某人說，“我得癌的可能性是50%”

and we said, "Hey, good news. Average likelihood is 30 percent,"

我們會說，“嘿，好消息。” 一般的可能性是30%”

the left inferior frontal gyrus would respond fiercely

左前下腦回將強烈的回應

And it didn't matter if you're an extreme optimist, a mild optimist or slightly pessimistic,

不論你是個極端樂觀主義者，溫和的樂觀主義者， 或是輕度的悲觀者

everyone's left inferior frontal gyrus was functioning perfectly well, whether you're Barack Obama or Woody Allen.

每個人的左前下腦回 都運作得很好 不管你是歐巴馬或是伍迪艾倫

On the other side of the brain, the right inferior frontal gyrus was responding to bad news

在腦的另一邊 右前下腦回只對壞消息有所回應

And here's the thing: it wasn't doing a very good job

事情來了: 它做得不是很好

The more optimistic you were, the less likely this region was to respond to unexpected negative information

你愈是樂觀 這個部份就不太可能 對意想不到的負面消息做出回應

And if your brain is failing at integrating bad news about the future, you will constantly leave your rose-tinted spectacles on.

如果你的大腦 無法整合與未來有關的壞消息 你就會一直保持樂觀

So we wanted to know, could we change this?

我們想知道，我們能改變嗎?

Could we alter people's optimism bias by interfering with the brain activity in these regions?

我們能不能透過干擾這些部份的腦活動 來改變人們的樂觀偏見?

And there's a way for us to do that.

我們有個方法可以做到

This is my collaborator Ryota Kanai.

這是我的合作人Ryota Kanai

And what he's doing is he's passing a small magnetic pulse through the skull of the participant in our study into their inferior frontal gyrus.

他正在做的就是把小型電磁脈衝 透過參加研究者的頭骨 傳送到他們的額下回

And by doing that, he's interfering with the activity of this brain region for about half an hour

這樣做 他的這些大腦區域活動就會被干擾 大約半小時

After that everything goes back to normal, I assure you.

我向你保證，之後就完全回復正常

So let's see what happens. First of all, I'm going to show you the average amount of bias that we see.

所以讓我們看看發生了什麼事。首先，我要給你們看的是 我們所見的偏見的平均量

So if I was to test all of you now, this is the amount that you would learn more from good news relative to bad news.

如果現在我要試試你們所有的人 這就是你們 相對於壞消息來說 聽到了更多好消息

Now we interfere with the region that we found to integrate negative information in this task, and the optimism bias grew even larger.

現在我們來干擾一下 我們找到的這個 整合負面消息的腦部區域 樂觀主義的偏見就會愈來愈大

We made people more biased in the way that they process information.

我們使得人們在處理消息的方面更加偏激

Then we interfered with the brain region that we found to integrate good news in this task, and the optimism bias disappeared

我們干擾腦區域 我們找到的這個 整合負面消息的腦部區域 而樂觀偏見就消失了

We were quite amazed by these results because we were able to eliminate a deep-rooted bias in humans.

我們對這些結果相當震驚 因為我們可以消除 人類根深蒂固的偏見

And at this point we stopped and we asked ourselves, would we want to shatter the optimism illusion into tiny little bits?

在這一點上我們停了下來而且問自己 是不是要把樂觀的幻想粉碎成一小片一小片?

If we could do that, would we want to take people's optimism bias away?

如果可以這樣做，我們會不會是想取走人們的樂觀偏見?

Well I've already told you about all of the benefits of the optimism bias,

我已經告訴你樂觀偏見的所有好處

which probably makes you want to hold onto it for dear life. But there are,

這些好處可能會讓你在生活中持續保有，但是這當然是

of course, pitfalls, and it would be really foolish of us to ignore them.

有圈套的，而且我們還蠢到忽略了他

Take for example this email I received from a firefighter here in California.

舉例來說，我收到一封電子郵件，來自一位加州的消防隊員

He says, "Fatality investigations for firefighters often include 'We didn't think the fire was going to do that,'

他說，“消防隊員的死亡調查 通常包括“我們不認為火勢會像這樣猛烈

even when all of the available information was there to make safe decisions.

即使所有現有的消息 都是安全的

This captain is going to use our findings on the optimism bias to try to explain to the firefighters why they think the way they do

這位隊長想使用我們在樂觀偏見上的研究結果，試著向消防隊員解釋，為什麼他們會這麼做

to make them acutely aware of this very optimistic bias in humans.

使得他們敏銳地意識到人類的樂觀偏見

So unrealistic optimism can lead to risky behavior, to financial collapse, to faulty planning.

所以不切實際的樂觀會導致危險的行為 導致金融崩潰，導致計劃錯誤

The British government, for example

英國政府就是個例子

has acknowledged that the optimism bias can make individuals more likely to underestimate the costs and durations of projects.

他們承認樂觀偏見 使得人們更有可能 低估了計劃的成本及持續期間

So they have adjusted the 2012 Olympic budget for the optimism bias.

所以他們調整了2012年奧林匹克的預算 就是因為樂觀偏見

My friend who's getting married in a few weeks has done the same for his wedding budget.

我有一個將在幾星期內結婚的朋友 也對結婚預算做了同樣的事

And by the way, when I asked him about his own likelihood of divorce,

順便一提的是，當我問他自己離婚的可能性時

he said he was quite sure it was zero percent.

他說他很確定是完全不可能

So what we would really like to do, is we would like to protect ourselves from the dangers of optimism,

所以我們真正想做的 是我們要保護自己免除樂觀危險

but at the same time remain hopeful, benefiting from the many fruits of optimism.

但同時保持深具希望 從樂觀的許多成果中獲益