TED日本語 - ババ・シフ: 運転は任せた方が良いこともある


TED Talks(英語 日本語字幕付き動画)

TED日本語 - ババ・シフ: 運転は任せた方が良いこともある

TED Talks

Sometimes it's good to give up the driver's seat
Baba Shiv




I want to start on a slightly somber note. Two thousand and seven,five years ago, my wife gets diagnosed with breast cancer, stage IIB. Now, looking back, the most harrowing part of that experience was not just the hospital visits -- these were very painful for my wife, understandably so. It was not even the initial shock of knowing that she had breast cancer, just 39 years old, absolutely no history of cancer in her family.

The most horrifying and agonizing part of the whole experience was we were making decisions after decisions after decisions that were being thrust upon us. Should it be a mastectomy? Should it be a lumpectomy? Should it be a more aggressive form of treatment, given that it was stage IIB? With all the side effects? Or should it be a less aggressive form of treatment? And these were being pressed upon us by the doctors.

Now, you could ask this question, why were the doctors doing this? Now, a simplistic answer would be, the doctors are doing this because they want to protect themselves legally. I think that is too simplistic. These are well-meaning doctors, some of them have gone on to become very good friends. They probably were simply following the wisdom that has come down the ages, this adage that when you're making decisions, especially decisions of importance, it's best to be in charge, it's best to be in control, it's best to be in the driver's seat.

And we were certainly in the driver's seat, making all these decisions, and let me tell you, if some of you had been there, it was a most agonizing and harrowing experience. Which got me thinking. I said, is there any validity to this whole adage that when you're making decisions, it's best to take the driver's seat, be in charge, be in control? Or are there contexts where we're far better off taking the passenger's seat and have someone else drive? For example, a trusted financial advisor, could be a trusted doctor, etc. And since I study human decision making, I said, I'm going to run some studies to find some answers.

And I'm going to share one of these studies with you today. So, imagine that all of you are participants in the study. I want to tell you that what you're going to do in the study is you're going to drink a cup of tea. If you're wondering why, I'll tell you why in a few seconds from now. You are going to solve a series of puzzles, and I'm going to show you examples of these puzzles momentarily. And the more puzzles you solve, the greater the chances that you'll win some prizes.

Now, why do you have to consume the tea? Why? Because it makes a lot of sense. In order to solve these puzzles effectively, if you think about it, your mind needs to be in two states simultaneously. Right? It needs to be alert, for which caffeine is very good. Simultaneously, it needs to be calm. Not agitated, calm. For which chamomile is very good.

Now comes the between-subjects design, the AB design, the AB testing. So what I'm going to do is randomly assign you to one of two groups. So imagine that there is an imaginary line out here, so everyone here will be group A, everyone out here will be group B.

Now, for you folks, what I'm going to do is I'm going to show you these two teas, and I'm asking you, I'll go ahead and ask you, to choose your tea. So you can choose which of the two tea you want. You can decide, what is your mental state: Okay, I'm going to choose the caffeinated tea, I'm going to choose the chamomile tea. So you're going to be in charge, you're going to be in control, you're going to be in the driver's seat.

You folks, I'm going to show you these two teas, but you don't have a choice. I'm going to give you one of these two teas, and keep in mind, I'm going to pick one of these two teas at random for you. And you know that. So if you think about it, this is an extreme case scenario, because in the real world, whenever you are taking passenger's seat, very often the driver is going to be someone you trust, an expert, etc. So this is an extreme case scenario.

Now, you're all going to consume the tea. So imagine that you are taking the tea now, we'll wait for you to finish the tea. We'll give another five minutes for the ingredient to have its effects.

Now you're going to have 30 minutes to solve 15 puzzles. Here's an example of the puzzle you're going to solve. Anyone in the audience want to take a stab?

(Audience: Pulpit.) Baba Shiv: Whoa! Okay, that's cool. Yeah, so what we do if we had you, who will get the answer, as a participant, we would have calibrated the difficulty level of the puzzles to your expertise. Because we want these puzzles to be difficult. These are tricky puzzles because your first instinct is to say "tulip," and then you have to unstick yourself. Right? So these have been calibrated to your level of expertise. Because we want this to be difficult, and I'll tell you why momentarily.

Now, here's another example. Anyone? It's much more difficult.

(Audience: Embark.) BS: Yeah, wow. Okay. So, yeah, so this is again difficult. You will say "kambar," then you will have to go, "maker," and all that, and then you can unstick yourself.

Okay, so you have 30 minutes now to solve these 15 puzzles. Now, the question we're asking here is in terms of the outcome, in terms of the number of puzzles solved, will you in the driver's seat end up solving more puzzles, because you are in control, you could decide which tea you will choose, or would you be better off, in terms of the number of puzzles solved? And systemically what we will show, across a series of studies, is that you, the passengers, even though the tea was picked for you at random, will end up solving more puzzles than you, the drivers.

We also observe another thing, and that is, you folks not only are solving fewer puzzles, you're also putting less juice into the task. Less effort, you're less persistent, and so on. How do you know that? Well we have two objective measures. One is, what is the time, on average, you're taking in attempting to solve these puzzles? You will spend less time compared to you. Second, you have 30 minutes to solve these, are you taking the entire 30 minutes, or are you giving up before the 30 minutes elapse? You will be more likely to give up before the 30 minutes elapse compared to you. So, you're putting in less juice, and therefore the outcome: fewer puzzles solved.

Now, that brings us now to, why does this happen? And under what situations, when would we see this pattern of results where the passenger is going to show better, more favorable outcomes compared to the driver?

It all has to do with when you face what I call the INCA. It's an acronym that stands for the nature of the feedback you're getting after you've made the decision. So, if you think about it, in this particular puzzle task, it could happen in investing in the stock market, very volatile out there, it could be the medical situation -- the feedback here is immediate. You know the feedback, whether you're solving the puzzles or not.

Right? Second, it is negative. Remember, the deck was stacked against you. In terms of the difficulty level of these puzzles. And this can happen in the medical domain. For example, very early on in the treatment, things are negative, the feedback, before things become positive. Right? It can happen in the stock market. Volatile stock market, getting negative feedback that's also immediate. And the feedback in all these cases is concrete. It's not ambiguous; you know if you've solved the puzzles or not.

Now, the added one, apart from this immediacy, negative, this concreteness, now you have a sense of agency. You were responsible for your decision. So what do you do? You focus on the foregone option. You say, you know what? I should have chosen the other tea.


That casts your decision in doubt, reduces the confidence you have in the decision, reduces the confidence you have in the performance, the performance in terms of solving the puzzles. And therefore less juice into the task, fewer puzzles solved, a less favorable outcome compared to you folks.

And this can happen in the medical domain, if you think about it. Right? A patient in the driver's seat, for example. Less juice, which means keeping herself or himself less physically fit, physically active to hasten the recovery process, which is what is often advocated. You probably wouldn't do that. And therefore, there are times when you're facing the INCA, when the feedback is going to be immediate, negative, concrete, and you have the sense of agency, where you're far better off taking the passenger's seat and have someone else drive.

Now, I started off on the somber note. I want to finish up on a more upbeat note. It has now been five years, slightly more than five years, and the good news, thank God, is that the cancer is still in remission.

So it all ends well, but one thing I didn't mention was that very early on into her treatment, my wife and I decided that we will take the passenger's seat. And that made so much of a difference in terms of the peace of mind that came with that, we could focus on her recovery. We let the doctors make all the decisions, take the driver's seat.

Thank you.


少し重い話になりますが 2007年―今から5年ほど前に 家内が乳がんと診断されました ステージ IIB でした いま当時を振り返って一番 苦しかったことは 病院に行くことではありません もちろん本人がつらいのはわかります 乳がんだと知らされた― ショックでもありませんまだ39歳で 癌の家族歴もなかったのです

この一連の経験でもっとも恐ろしくて 苦しかったのは 決断を次から次へと 求められ続けたことです 乳房切除をすべきか?それとも乳腺腫瘤の摘出か? ステージ IIB なのだから 積極的な治療に委ねるべきなのか? 副作用があっても? それとも そこまで積極的でなくてもいいのか? 次から次へと決断を求めてくるのが 医師なのです

不思議に思うかもしれません 医師はなぜ こうしたのか? 単純に考えると医者自身が 法的に自分を守りたいためですが 実はそんな単純な話ではありません 彼らは善意の医者であり 何人かとは良い友人になりました きっと長年受け継がれてきた 古い考え方に従ったまでなのでしょう 「意思決定特に重責を伴う意思決定は 他人の判断に任せずに 自分の意思で決めよ つまり助手席に座るよりも運転席に乗るべきである」

そこで我々は運転席に座らせられ 多くの意思決定を下すことになったのです 同じ経験をされた方もいるでしょうが 何よりも苦しくて恐ろしい経験となりました そして考えてみました― 決断をすることに関する考え方は 本当に正しいのだろうか? 運転席に乗ることが一番良いのか?主導権を握って 制御するのが良いのか 逆に 状況によっては我々が助手席におさまり 誰かに運転席を任せた方が良い場合もあるのでは? 例えば 信頼できる金融専門家や 信頼できる医者などです 私は「意思決定の仕組み」を研究していますので いくつかの実験を行い 答えを導き出すことにしました

早速 ここで研究成果のひとつをご紹介します 皆さんは その実験に参加しているつもりで聞いてください この実験では皆さんに まず 一杯のお茶を飲んでいただきます お茶を飲む理由は後で説明します そしてパズルをいくつか解いてもらいます パズルの実例も後ほどお見せします 正解数が多ければ多いほど 賞品をもらえる可能性が大きくなります

ところでなぜお茶を飲むのか? 理由は単純明快です パズルを効果的に解くために 精神が同時に2つの状態にならないといけません そうでしょう?神経がピンと張り詰めた状態 これにはカフェインが効果的ですし 同時に 心穏やかでなければいけません 苛つかず 心が落ち着いた状態これにはカモミールが最適です

さて被験者間で何を変えるのかというABテストの デザインを説明します 早速ですが 皆さんを適当に 2つのグループに分けます ここに架空の線があると想像してください こちらの皆さんはグループAに こちらの皆さんはグループBにします

グループAの皆さんには 2種類のお茶をお見せして 自分で好きな方を 選んでいただきます さぁ 選んでみてください決めましたか? そうだ 私はカフェイン入りのお茶を 私はカモミールを選ぼう 自分で決める― 選択権を持ち運転席に座っているのです

グループBの皆さんここに2種類のお茶がありますが 選んでいただくことはできません どちらかをお渡しします どちらか一方のお茶を ランダムにお渡しします 覚えておいてください もちろん これは非常に極端な例です なぜなら 実社会では あなたが助手席に座るときにはまず たいてい運転席には信頼をおける人や 専門家がいる筈だからですこれはかなり極端なシナリオです

ここで皆さんにはお茶を飲んでいただきます お茶を楽しんでください 飲み終るまでもう少し待ちましょう お茶の成分が効果を発揮するまであと5分ほど待ちましょう

さて これから30分かけて15問のパズルを解いてください ひとつサンプルをご紹介します どなたか分かりますか?(文字の並び替えクイズ)

(観衆:PULPIT ) 素晴らしい! 凄いですね! さて あなたのようにすぐ解る人がいたらどうするか 被験者のレベルに合わせて パズルの難易度を 調整する必要がありました 簡単に解けては無意味ですから このクイズは実に巧妙にできてて 本能的に TULIP に見えるので 慌てて頭を切り替えたり― しなくてはいけませんね つまり適切な難易度に設定されています 後に説明しますが簡単に解けては意味がありません

それではサンプル問題をもうひとつ 分かりますか?少し難しいかな?

(観客:EMBARK ) 正解! こちらも難しかったでしょう KAMBAR や MAKER など ひっかけがたくさんあるのです

このような問題15問を 30分間で解いてもらいます この実験で 注目していることがあります 正解数が多いのは 運転席に乗る場合の 方でしょうか? つまり 飲むお茶を選択できたからこそ成果が上がるのか それともグループBの方が 正解数が多いのでしょうか? 系統的な調査データをもとに 分析した結果 実は助手席にいる方が お茶はランダムに割り当てられたものなのに 運転席にいる方よりも多く正解しました

もうひとつ分かったことは 運転席にいる方は回答数が少ないうえ 集中力を欠いています 努力が足りず 粘り強さもない なぜわかるのか? 2つの客観的指標があるのです ひとつは問題を解くのに かけた解答時間の平均です グループAの方が平均解答時間が短かったのです 二つ目です制限時間は30分ありますが 最後まで諦めずがんばるか?あるいは30分より 前に途中棄権するのか? グループAの方が途中棄権する確率が高かったのです 集中力を欠いていることは結果にも現れます 正解数が少ないのです

ではなぜ こんな結果になるのか どのような状況だとこういう結果に― つまり助手席側の方が運転席側よりも 良い成果を出せるのか?

INCA と名付けたもの遭遇する場合に問題となるのです INCA は 意思決定の後のフィードバックの 性質を表す言葉の頭文字です 今回のパズル実験を思い出してみてください 変化の激しい株式投資や 病気の場合でも同じですが 結果は 直ちに分かりますよね (Immediate) パズルが解けたかどうか すぐ分かります

そして 結果は通常良くない (Negative) パズルの難易度は 意図的に高く設定されていました これは医療の現場でも同じです 例えば 治療のごく初期には 良い結果も見えず状況や手ごたえは厳しいものです これは株式市場でも同じです 荒れた株式市場では直ちに否定的な結果が得られます そして フィードバックは具体的です (Concrete) 曖昧ではありません正解か 不正解か

さらにこの「即時性 (I)」 「ネガティブ (N)」「具体的 (C)」に 「主体感 (Agency)」が加わります 自分の決断には責任が伴います するとどうなるのか? 選ばなかった選択肢が気になるのです だから もう一方のお茶を選んでればよかったのに―


心の迷いが 意思決定を乱し 意思決定の自信低下 良い成果への自信低下 問題解決能力の低下につながります 課題解決に身が入らないので 正解数が少なくグループBより劣る結果となります

これは医療分野でも十分に起こりえますね 患者を運転席に座らせた場合 活力に欠け 回復のプロセスを促す 運動や 健康維持の努力に身が入らなくなってしまいます 大切だといわれているのにですこれは良くないですね ですからINCAに遭遇したら フィードバックが即時でネガティブであり 具体的で 自己責任を感じる時 その場合は―誰かに運転席を任せ 助手席に座ったほうがずっと良いのです

今日は重苦しい トーンで始まったので 最後は陽気なトーンで締め括りましょう あれから5年が経過し―正確には5年以上ですが 非常に喜ばしいことに 家内の癌は未だ寛解期に留まっています

治療も順調に進んだわけです ただし ひとつだけ言ってなかったことがあります 二人で相談した結果家内の初期治療のときから 我々は助手席に座ることを決めました そのことで得られた心の平安のおかげで 病気の回復に集中できたことが この結果につながったと思います 我々は医者に運転席を譲り すべての意思決定を任せました



― もっと見る ―
― 折りたたむ ―


  • 主語
  • 動詞
  • 助動詞
  • 準動詞
  • 関係詞等