TED日本語 - ダン・アリエリー: 私たちのモラルに潜む落とし穴


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TED日本語 - ダン・アリエリー: 私たちのモラルに潜む落とし穴

TED Talks


Our buggy moral code


Dan Ariely






I want to talk to you today a little bit about predictable irrationality. And my interest in irrational behavior started many years ago in the hospital. I was burned very badly. And if you spend a lot of time in hospital, you'll see a lot of types of irrationalities. And the one that particularly bothered me in the burn department was the process by which the nurses took the bandage off me. Now, you must have all taken a Band-Aid off at some point, and you must have wondered what's the right approach. Do you rip it off quickly -- short duration but high intensity -- or do you take your Band-Aid off slowly -- you take a long time, but each second is not as painful -- which one of those is the right approach?

The nurses in my department thought that the right approach was the ripping one, so they would grab hold and they would rip, and they would grab hold and they would rip. And because I had 70 percent of my body burned, it would take about an hour. And as you can imagine, I hated that moment of ripping with incredible intensity. And I would try to reason with them and say, "Why don't we try something else? Why don't we take it a little longer -- maybe two hours instead of an hour -- and have less of this intensity?" And the nurses told me two things. They told me that they had the right model of the patient -- that they knew what was the right thing to do to minimize my pain -- and they also told me that the word patient doesn't mean to make suggestions or to interfere or ... This is not just in Hebrew, by the way. It's in every language I've had experience with so far.

And, you know, there's not much -- there wasn't much I could do, and they kept on doing what they were doing. And about three years later, when I left the hospital, I started studying at the university. And one of the most interesting lessons I learned was that there is an experimental method that if you have a question you can create a replica of this question in some abstract way, and you can try to examine this question, maybe learn something about the world.

So that's what I did. I was still interested in this question of how do you take bandages off burn patients. So originally I didn't have much money, so I went to a hardware store and I bought a carpenter's vice. And I would bring people to the lab and I would put their finger in it, and I would crunch it a little bit.


And I would crunch it for long periods and short periods, and pain that went up and pain that went down, and with breaks and without breaks -- all kinds of versions of pain. And when I finished hurting people a little bit, I would ask them, so, how painful was this? Or, how painful was this? Or, if you had to choose between the last two, which one would you choose?


I kept on doing this for a while.


And then, like all good academic projects, I got more funding. I moved to sounds, electrical shocks -- I even had a pain suit that I could get people to feel much more pain.

But at the end of this process, what I learned was that the nurses were wrong. Here were wonderful people with good intentions and plenty of experience, and nevertheless they were getting things wrong predictably all the time. It turns out that because we don't encode duration in the way that we encode intensity, I would have had less pain if the duration would have been longer and the intensity was lower. It turns out it would have been better to start with my face, which was much more painful, and move toward my legs, giving me a trend of improvement over time -- that would have been also less painful. And it also turns out that it would have been good to give me breaks in the middle to kind of recuperate from the pain. All of these would have been great things to do, and my nurses had no idea.

And from that point on I started thinking, are the nurses the only people in the world who get things wrong in this particular decision, or is it a more general case? And it turns out it's a more general case -- there's a lot of mistakes we do. And I want to give you one example of one of these irrationalities, and I want to talk to you about cheating. And the reason I picked cheating is because it's interesting, but also it tells us something, I think, about the stock market situation we're in. So, my interest in cheating started when Enron came on the scene, exploded all of a sudden, and I started thinking about what is happening here. Is it the case that there was kind of a few apples who are capable of doing these things, or are we talking a more endemic situation, that many people are actually capable of behaving this way?

So, like we usually do, I decided to do a simple experiment. And here's how it went. If you were in the experiment, I would pass you a sheet of paper with 20 simple math problems that everybody could solve, but I wouldn't give you enough time. When the five minutes were over, I would say, "Pass me the sheets of paper, and I'll pay you a dollar per question." People did this. I would pay people four dollars for their task -- on average people would solve four problems. Other people I would tempt to cheat. I would pass their sheet of paper. When the five minutes were over, I would say, "Please shred the piece of paper. Put the little pieces in your pocket or in your backpack, and tell me how many questions you got correctly." People now solved seven questions on average. Now, it wasn't as if there was a few bad apples -- a few people cheated a lot. Instead, what we saw is a lot of people who cheat a little bit.

Now, in economic theory, cheating is a very simple cost-benefit analysis. You say, what's the probability of being caught? How much do I stand to gain from cheating? And how much punishment would I get if I get caught? And you weigh these options out -- you do the simple cost-benefit analysis, and you decide whether it's worthwhile to commit the crime or not. So, we try to test this. For some people, we varied how much money they could get away with -- how much money they could steal. We paid them 10 cents per correct question,50 cents, a dollar,five dollars,10 dollars per correct question.

You would expect that as the amount of money on the table increases, people would cheat more, but in fact it wasn't the case. We got a lot of people cheating by stealing by a little bit. What about the probability of being caught? Some people shredded half the sheet of paper, so there was some evidence left. Some people shredded the whole sheet of paper. Some people shredded everything, went out of the room, and paid themselves from the bowl of money that had over 100 dollars. You would expect that as the probability of being caught goes down, people would cheat more, but again, this was not the case. Again, a lot of people cheated by just by a little bit, and they were insensitive to these economic incentives.

So we said, "If people are not sensitive to the economic rational theory explanations, to these forces, what could be going on?" And we thought maybe what is happening is that there are two forces. At one hand, we all want to look at ourselves in the mirror and feel good about ourselves, so we don't want to cheat. On the other hand, we can cheat a little bit, and still feel good about ourselves. So, maybe what is happening is that there's a level of cheating we can't go over, but we can still benefit from cheating at a low degree, as long as it doesn't change our impressions about ourselves. We call this like a personal fudge factor.

Now, how would you test a personal fudge factor? Initially we said, what can we do to shrink the fudge factor? So, we got people to the lab, and we said, "We have two tasks for you today." First, we asked half the people to recall either 10 books they read in high school, or to recall The Ten Commandments, and then we tempted them with cheating. Turns out the people who tried to recall The Ten Commandments -- and in our sample nobody could recall all of The Ten Commandments -- but those people who tried to recall The Ten Commandments, given the opportunity to cheat, did not cheat at all. It wasn't that the more religious people -- the people who remembered more of the Commandments -- cheated less, and the less religious people -- the people who couldn't remember almost any Commandments -- cheated more. The moment people thought about trying to recall The Ten Commandments, they stopped cheating. In fact, even when we gave self-declared atheists the task of swearing on the Bible and we give them a chance to cheat, they don't cheat at all. Now,Ten Commandments is something that is hard to bring into the education system, so we said, "Why don't we get people to sign the honor code?" So, we got people to sign, "I understand that this short survey falls under the MIT Honor Code." Then they shredded it. No cheating whatsoever. And this is particularly interesting, because MIT doesn't have an honor code. (Laughter)

So, all this was about decreasing the fudge factor. What about increasing the fudge factor? The first experiment -- I walked around MIT and I distributed six-packs of Cokes in the refrigerators -- these were common refrigerators for the undergrads. And I came back to measure what we technically call the half-lifetime of Coke -- how long does it last in the refrigerators? As you can expect it doesn't last very long; people take it. In contrast, I took a plate with six one-dollar bills, and I left those plates in the same refrigerators. No bill ever disappeared.

Now, this is not a good social science experiment, so to do it better I did the same experiment as I described to you before. A third of the people we passed the sheet, they gave it back to us. A third of the people we passed it to, they shredded it, they came to us and said, "Mr. Experimenter, I solved X problems. Give me X dollars." A third of the people, when they finished shredding the piece of paper, they came to us and said, "Mr Experimenter, I solved X problems. Give me X tokens." We did not pay them with dollars; we paid them with something else. And then they took the something else, they walked 12 feet to the side, and exchanged it for dollars.

Think about the following intuition. How bad would you feel about taking a pencil from work home, compared to how bad would you feel about taking 10 cents from a petty cash box? These things feel very differently. Would being a step removed from cash for a few seconds by being paid by token make a difference? Our subjects doubled their cheating. I'll tell you what I think about this and the stock market in a minute. But this did not solve the big problem I had with Enron yet, because in Enron, there's also a social element. People see each other behaving. In fact, every day when we open the news we see examples of people cheating. What does this cause us?

So, we did another experiment. We got a big group of students to be in the experiment, and we prepaid them. So everybody got an envelope with all the money for the experiment, and we told them that at the end, we asked them to pay us back the money they didn't make. OK? The same thing happens. When we give people the opportunity to cheat, they cheat. They cheat just by a little bit, all the same. But in this experiment we also hired an acting student. This acting student stood up after 30 seconds, and said, "I solved everything. What do I do now?" And the experimenter said, "If you've finished everything, go home. That's it. The task is finished." So, now we had a student -- an acting student -- that was a part of the group. Nobody knew it was an actor. And they clearly cheated in a very, very serious way. What would happen to the other people in the group? Will they cheat more, or will they cheat less?

Here is what happens. It turns out it depends on what kind of sweatshirt they're wearing. Here is the thing. We ran this at Carnegie Mellon and Pittsburgh. And at Pittsburgh there are two big universities, Carnegie Mellon and University of Pittsburgh. All of the subjects sitting in the experiment were Carnegie Mellon students. When the actor who was getting up was a Carnegie Mellon student -- he was actually a Carnegie Mellon student -- but he was a part of their group, cheating went up. But when he actually had a University of Pittsburgh sweatshirt, cheating went down.


Now, this is important, because remember, when the moment the student stood up, it made it clear to everybody that they could get away with cheating, because the experimenter said, "You've finished everything. Go home," and they went with the money. So it wasn't so much about the probability of being caught again. It was about the norms for cheating. If somebody from our in-group cheats and we see them cheating, we feel it's more appropriate, as a group, to behave this way. But if it's somebody from another group, these terrible people -- I mean, not terrible in this -- but somebody we don't want to associate ourselves with, from another university, another group, all of a sudden people's awareness of honesty goes up -- a little bit like The Ten Commandments experiment -- and people cheat even less.

So, what have we learned from this about cheating? We've learned that a lot of people can cheat. They cheat just by a little bit. When we remind people about their morality, they cheat less. When we get bigger distance from cheating, from the object of money, for example, people cheat more. And when we see cheating around us, particularly if it's a part of our in-group, cheating goes up. Now, if we think about this in terms of the stock market, think about what happens. What happens in a situation when you create something where you pay people a lot of money to see reality in a slightly distorted way? Would they not be able to see it this way? Of course they would. What happens when you do other things, like you remove things from money? You call them stock, or stock options, derivatives, mortgage-backed securities. Could it be that with those more distant things, it's not a token for one second, it's something that is many steps removed from money for a much longer time -- could it be that people will cheat even more? And what happens to the social environment when people see other people behave around them? I think all of those forces worked in a very bad way in the stock market.

More generally, I want to tell you something about behavioral economics. We have many intuitions in our life, and the point is that many of these intuitions are wrong. The question is, are we going to test those intuitions? We can think about how we're going to test this intuition in our private life, in our business life, and most particularly when it goes to policy, when we think about things like No Child Left Behind, when you create new stock markets, when you create other policies -- taxation, health care and so on. And the difficulty of testing our intuition was the big lesson I learned when I went back to the nurses to talk to them.

So I went back to talk to them and tell them what I found out about removing bandages. And I learned two interesting things. One was that my favorite nurse, Ettie, told me that I did not take her pain into consideration. She said, "Of course, you know, it was very painful for you. But think about me as a nurse, taking, removing the bandages of somebody I liked, and had to do it repeatedly over a long period of time. Creating so much torture was not something that was good for me, too." And she said maybe part of the reason was it was difficult for her. But it was actually more interesting than that, because she said, "I did not think that your intuition was right. I felt my intuition was correct." So, if you think about all of your intuitions, it's very hard to believe that your intuition is wrong. And she said, "Given the fact that I thought my intuition was right ..." -- she thought her intuition was right -- it was very difficult for her to accept doing a difficult experiment to try and check whether she was wrong.

But in fact, this is the situation we're all in all the time. We have very strong intuitions about all kinds of things -- our own ability, how the economy works, how we should pay school teachers. But unless we start testing those intuitions, we're not going to do better. And just think about how better my life would have been if these nurses would have been willing to check their intuition, and how everything would have been better if we just start doing more systematic experimentation of our intuitions.

Thank you very much.

今日のテーマは 「予想通りの不合理さ」です 私が「不合理な行動」に興味を持ったのは ずいぶん前に病院でのこと 私は酷い火傷を負ったことがあります 病院で何年か過ごす間に 色々な不合理さが目につき 特に 火傷病棟で私の頭を悩ませたのは 看護師たちの包帯の剥がし方です さて 今皆さんはバンドエイドを 剥がそうとしています さっさと剥がして 短いが激しい痛みに耐えるか ゆっくり剥がして 長めの穏やかな痛みに耐えるか どちらがよいでしょう?

私の病棟の看護師たちの持論は さっさと剥がす方で かまえては引き剥がし かまえては一気に引き剥がしたのです 私の火傷は全身の70%に及びましたから 一時間はかかり 引き剥がす間の あの恐ろしい痛みが嫌でしたね だから ある時頼んでみました 「もう少し ゆっくりと剥がしてよ 2時間ぐらいはかけて 痛みを和らげられないの」と 看護師が言うには 自分たちは患者の扱い方を知っているし 痛みを抑える方法もわかっている それに「患者」という言葉に 「助言」や「邪魔」をする意味はないと 私が知る限りでは このことは万国共通のようです

とにかく 私にはどうにもできないまま 看護師は同じように続けました それから3年後には退院して 大学で勉強を始めました そこで面白いことを学びました 自分が疑問に思うことを 抽象的な質問の形に作り変え その質問の答を探ることで この世界について 少しヒントが得られることを知ったのです

だから試してみました 私はその時もまだ 火傷患者の包帯の剥がし方が気になっていました 初めは あまりお金がなく 万力を買ってきて 研究室に人を集めて 指を間に挟ませ 少しだけ締めてみました


長めに締め付けたり 短めだったり 痛みを強めては弱め しばらく続けたあとには少し間をあけて 痛みを与えるたびに どう痛かったか? 選ぶとすれば どちらの痛みを選ぶか?と聞きました




研究費をもらえるようになってからは 他の痛みも試してみました 不快な音 電気ショック 拷問スーツまで

そしてこれらの実験から 看護師たちが 間違っていたことがわかりました 看護師たちは あれだけの善意と 経験を持ち合わせても 予想通り間違うことを証明したのです 私たちは 持続時間と痛みの強さを 同じ計りで計っていないようです もしゆっくりと包帯を剥がしていたら ずっと痛みは軽減されていたでしょう より痛みの強い顔の方から脚の方へ 包帯を剥がしていたら 苦痛は軽い方へ向かうのですから 恐らく痛みも和らいでいたでしょう また 途中で少し 休憩を入れてもよかったようです 改善の余地はありました しかし 看護師は知らなかったのです

そこで私が考えたのは これは看護師に限ったことなのか もっと一般的に当てはまるのか ということです 答えは後者です 私たちは多くの間違いを犯します この不合理の具体例の一つが 不正行為です ここで紹介する興味深い実験は 昨今の混沌とした証券市場にも 応用できます 私がはじめに不正に興味を持ったのは 2001年のエンロン事件です 一体何が起こっていたのでしょう これは 少数の悪い人間の行いなのか それとも人間に特有の 誰もが犯しうる過ちだったのでしょうか

そこで いつも通り 単純な実験を 行ってみました 皆さんに 紙を一枚配るとします 簡単な誰もが解ける数学の問題20問です しかし 十分な時間がありません 制限時間は5分で 答案を回収します 一問正解につき一ドル払います 平均正解数は4問 平均4ドル渡しました 次に 別の人たちにはわざと不正を働くよう仕掛けをします 今度も 紙を配り 5分後にこう言います 「紙を破き ポケットか鞄にしまってください そして 何問正解したかを教えてください」 正解は平均7問に増えました これは 少数の悪人が たくさんズルをしたのではなく 実は 多くの人が少しズルをしたのです

さて 経済学の理論では 不正は単純な費用便益分析の一例です 捕まる確率は? 不正から得られる価値はいくらか? 捕まったらどんな罰を受けるのか? これらを計りにかけます これが単純な費用便益分析です そして 罪を犯す価値があるかどうかを決めます そこで 次の実験では 持ち逃げさせる金額を変えてみました いくらなら盗むか 一問あたり 10セント 50セント 1ドル 5ドル 10ドルと変えてみました

皆さんは 金額が大きいほど不正が増える と思うでしょうが 実際は違いました 多くの人がわずかだけ盗んだのです また 捕まる可能性は? ある人は紙を半分だけ破き 証拠を残し ある人は丸々一枚破き ある人は粉々にして 部屋を出てゆき 100ドルは入っているボウルからお金をとりました ここでは 捕まる可能性が低い方が 不正が増えるようですが 同じく 違いました やはり 多くの人が少しだけ不正をしました つまり 経済的なインセンティブに反応しなかったのです

このように 人々が経済の合理性に見合わない行動をとる そこで何が起きているのか考えてみました 私が考えるに そこには2つの力が働いています 一つは 自分の姿を鏡に映し出し 自尊心から 不正を抑えようとする力 もう一つは 少しだけなら不正をしても 自尊心はまだ保てるという力です つまり 超えてはいけない一線を守りながら 自分の評価を傷つけない程度に 些細な不正から何かを得ようとするのです これを「私的補正因子」と言います

この「私的補正因子」はどのようにテストできるでしょう? また「私的補正因子」を減らすにはどうしたらよいでしょうか? そこで人々を研究室に集め 二つの課題を与えました まず 半分の人に 高校時代に読んだ本を10冊 他の人には「十戒」を思い出してもらうように指示します ここでもまた わざとズルをする細工をしました 結果は 「十戒」を指示された人は 誰も10個全ては思い出せませんでした でも わざとズルができるようにしたにも関わらず 誰も不正を働かなかったのです これは 特に熱心な信者が ズルをしなかった訳でもなく 「十戒」と無縁な人が よりズルをした 訳でもありません 「十戒」を思い出そうとした瞬間すでに 不正はなくなったのです 自称 無宗教者ですら 聖書に手を置き 誓いをたてると 不正を働く気はなくなったのです さて「十戒」は宗教的で 教育現場には不向きですから 倫理規定を使って実験を続けることにしました 倫理規定に 「私はここに この調査がMIT倫理規定の適用を受けることを理解しました」と 署名させ それを破かせました この場合も不正はなくなりました しかし 面白いことにMITには倫理規定などはありません (笑)

これは全て「私的補正因子」を減らすために起こったのです それでは「私的補正因子」はどのような時に増えるのでしょう はじめに 私はキャンパスを歩き回り 6缶入りのコーラを様々な場所の冷蔵庫に置きました 学部生用の共有冷蔵庫です 私たちは「半生分のコーラ」と呼んでますが どれぐらい保つか調べてみたのです おわかりの通り それほど長くはありません しかし 代わりに6ドルをのせたお皿を 同じように冷蔵庫にいれても 一枚も無くならなかったのです

され これではよい社会学実験と言えません そこで私が先ほど説明した実験を 再度行ってみました 今度は3分の1の人は 紙を私達に戻します また別の3分の1は 紙を破き 私達の所へ来て 「試験官 私はX問正解しましたから Xドルください」と言います 他の3分の1の人は 紙を破き 私達の所へ来て 「試験官 私はX問正解しましたから X枚引換券をください」と言います つまり お金で支払うのではなく 別の物で支払いました その別の物をもらい 12フィートほど歩いて行って 換金します

直感的に考えてみてください 職場から鉛筆を一本盗む時と ちょっと10セントほど小銭を盗むのでは どちらが罪悪感をより強く感じますか? この二つには大きな違いがあります 現金ではなく引換券であったならば どう違うというのでしょうか? 実際 不正は2倍に増えたのです ここで私が考えたのは この実験と証券市場の関連です もちろん 社会的な要素の強いエンロン事件のような 大きな事件の解決にはなりません 要するに 人は他人の振りをみているわけです 事実 毎日ニュースをチェックし 人々の不正を目撃します そこからどんな影響を受けるのでしょうか?

そこで別の実験をしてみました 大勢の学生を集めて実験協力謝金を 先に渡しました 全員 お金が入った封筒を手にします そして最後に 正解できなかった問題の数だけ お金を返すように言いました 結果はさほど変わりません 不正を働く機会があると 人々はそうします しかも 多くの人が少しだけズルをするのです ただ 今回の実験では偽物の学生を一人混ぜ 30秒後に立ち上がらせ こう言わせます 「全部正解したら どうしたらよいですか?」 そして試験官は全て終わったなら そのまま帰るように言います これだけです さてこの偽物学生は グループの中に溶け込み 誰も 演技をしていることは知りません そして もちろん皆真面目に不正を行うのです すると グループの他の人はどうするでしょう? もっとズルをするか しないか?

結果はこうです 実は 結果は着ているパーカーによって違いました つまり この実験をピッツバーグで行いましたが そこには二つの大学があります カーネギーメロン大学とピッツバーグ大学です 実験の参加者はみな カーネギーメロン大学の学生です 演技をしている学生がカーネギーメロンの学生の時 実際 彼はそうでしたが 彼はグループの一員であり 不正は増加しました しかし ピッツバーグ大学のパーカーを着てみたら 不正は減ったのです


これは大切なことです 考えてみて下さい 学生が立ち上がった瞬間 全員がズルをして帰っても良いという認識をもちました 試験官が「全問終わったら 帰ってよい」というので 皆帰ったのです つまり ここでもまた単に捕まる可能性が問題なのではありません これは不正してもよいかの判断の基準が問題なのです 同じグループの人がズルをし それを見たならば 同じメンバーとして ズルをしてもよいという気になります しかし その人が違うグループならば 最悪な人たち いや この実験には最悪な人など本当はいませんよ つまり 出来れば関係を保ちたくない人 別の大学の学生であるとかだと 急に 人々は正直になるわけです これは「十戒」の実験に似ていますが ズルをする人は減ったのです

さて ここから何が学べるでしょう? まず 多くの人が不正をすることはわかりました しかも ほんの少しだけズルをします ところが モラルに少しでも触れたとたん 不正は減ります 不正と少し距離が離れると 例えばお金以外のものだと ズルは増えます そして周りの人がズルをしているのを見ると 特に同じ仲間だと ズルは増えるのです これを 証券市場に当てはめてみると どうでしょうか 多額のお金を他の何かで支払うと つまり現実を少し曲げて 見るとどうなるでしょう この実験があてはまることが おわかりでしょう? 少し現金から離れたとたん 何がおこるのでしょう? 株券だとか オプションだとか デリバティブとか 土地担保証券だとかありますよね こうして非現金のものを使うと 引換券ではないにしても 現金からは何段階も離れているわけで 長い目でみれば 人はよりズルをする傾向にあるのではないでしょうか? さらに このような他人の行動を見ることは 社会環境にどう影響を及ぼすのでしょう? 私はこれらの要因は全て証券市場では 悪い方へ向かうと考えます

一般的には 行動経済学では 次のようなことが言えます 私達は直観にかなり頼っていて 多くの場合その直観は間違っています 問題は そのような直観を省みるかどうかにあります 自分たちが毎日の生活 ビジネス 特に政策決定の場で 直観をどう使っているか考えてみるのです 例えば 教育制度だとか 新しい証券市場を作る時や 税制や社会福祉など 新しい政策を作る時です そして この直観を確かめる難しさは 私自身がよく知っています 病院に戻って看護師たちと話した時

こんなことがありました 包帯の剥がし方についてわかったことを教えると 二つの面白い答えが返ってきました 私が好きだった看護師のエティは まず 看護師の気持ちを考えてないと言いました エティは「もちろんあなたの痛みは当然だけど 看護師のことも考えてみて 大好きな人の包帯を取る辛さを しかも何度 何度も繰り返し 苦しめ続けるのは 私にとっても楽なことではなかった」と ところが それほど彼女を苦しめた理由は もっと興味深い別の点にあって 「私は他人の直観が正しいと思ったことなどなく 自分の直観が正しいと思った」と続けました もし自分の身に置き換えてみれば 自分の直観が間違っていると思うのは相当に難しいことです そして 彼女が言うには 私が自分の直観を正しいと思ったように 彼女も自分の直観を正しいと思い 別の視点をもつのはほぼ不可能なことだったのです 自分が間違っているかどうか考えもしなかった

しかし 実際には これはよくあることです 私達はあらゆることを強い直感を持って判断しています 自分の能力や これから経済がどう動くか 教師にいくら給料を払うか しかし この直観は確かめてみない限り 改善の余地はないのです もしあの看護師が自分たちの直観に疑いをもつことがあれば 私の病院生活はどれほど楽になっていたか 自分の直感をより体系的に 調べることができれば 物事はもう少し上手く運んでいたのではないでしょうか


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