TED日本語 - ダニエル・カーネマン: 経験と記憶の謎

Everybody talks about happiness these days. I had somebody count the number of books with "happiness" in the title published in the last five years and they gave up after about 40, and there were many more. There is a huge wave of interest in happiness, among researchers. There is a lot of happiness coaching. Everybody would like to make people happier. But in spite of all this flood of work, there are several cognitive traps that sort of make it almost impossible to think straight about happiness.

And my talk today will be mostly about these cognitive traps. This applies to laypeople thinking about their own happiness, and it applies to scholars thinking about happiness, because it turns out we're just as messed up as anybody else is. The first of these traps is a reluctance to admit complexity. It turns out that the word "happiness" is just not a useful word anymore, because we apply it to too many different things. I think there is one particular meaning to which we might restrict it, but by and large, this is something that we'll have to give up and we'll have to adopt the more complicated view of what well-being is. The second trap is a confusion between experience and memory; basically, it's between being happy in your life, and being happy about your life or happy with your life. And those are two very different concepts, and they're both lumped in the notion of happiness. And the third is the focusing illusion, and it's the unfortunate fact that we can't think about any circumstance that affects well-being without distorting its importance. I mean, this is a real cognitive trap. There's just no way of getting it right.

Now, I'd like to start with an example of somebody who had a question-and-answer session after one of my lectures reported a story, and that was a story -- He said he'd been listening to a symphony, and it was absolutely glorious music and at the very end of the recording, there was a dreadful screeching sound. And then he added, really quite emotionally, it ruined the whole experience. But it hadn't. What it had ruined were the memories of the experience. He had had the experience. He had had 20 minutes of glorious music. They counted for nothing because he was left with a memory; the memory was ruined, and the memory was all that he had gotten to keep.

What this is telling us, really, is that we might be thinking of ourselves and of other people in terms of two selves. There is an experiencing self, who lives in the present and knows the present, is capable of re-living the past, but basically it has only the present. It's the experiencing self that the doctor approaches -- you know, when the doctor asks, "Does it hurt now when I touch you here?" And then there is a remembering self, and the remembering self is the one that keeps score, and maintains the story of our life, and it's the one that the doctor approaches in asking the question, "How have you been feeling lately?" or "How was your trip to Albania?" or something like that. Those are two very different entities, the experiencing self and the remembering self, and getting confused between them is part of the mess about the notion of happiness.

Now, the remembering self is a storyteller. And that really starts with a basic response of our memories -- it starts immediately. We don't only tell stories when we set out to tell stories. Our memory tells us stories, that is, what we get to keep from our experiences is a story. And let me begin with one example. This is an old study. Those are actual patients undergoing a painful procedure. I won't go into detail. It's no longer painful these days, but it was painful when this study was run in the 1990s. They were asked to report on their pain every 60 seconds. Here are two patients, those are their recordings. And you are asked, "Who of them suffered more?" And it's a very easy question. Clearly, Patient B suffered more -- his colonoscopy was longer, and every minute of pain that Patient A had, Patient B had, and more.

But now there is another question: "How much did these patients think they suffered?" And here is a surprise. The surprise is that Patient A had a much worse memory of the colonoscopy than Patient B. The stories of the colonoscopies were different, and because a very critical part of the story is how it ends. And neither of these stories is very inspiring or great -- but one of them is this distinct ... (Laughter) but one of them is distinctly worse than the other. And the one that is worse is the one where pain was at its peak at the very end; it's a bad story. How do we know that? Because we asked these people after their colonoscopy, and much later, too, "How bad was the whole thing, in total?" And it was much worse for A than for B, in memory.

Now this is a direct conflict between the experiencing self and the remembering self. From the point of view of the experiencing self, clearly, B had a worse time. Now, what you could do with Patient A, and we actually ran clinical experiments, and it has been done, and it does work -- you could actually extend the colonoscopy of Patient A by just keeping the tube in without jiggling it too much. That will cause the patient to suffer, but just a little and much less than before. And if you do that for a couple of minutes, you have made the experiencing self of Patient A worse off, and you have the remembering self of Patient A a lot better off, because now you have endowed Patient A with a better story about his experience. What defines a story? And that is true of the stories that memory delivers for us, and it's also true of the stories that we make up. What defines a story are changes, significant moments and endings. Endings are very, very important and, in this case, the ending dominated.

Now, the experiencing self lives its life continuously. It has moments of experience,one after the other. And you can ask: What happens to these moments? And the answer is really straightforward: They are lost forever. I mean, most of the moments of our life -- and I calculated, you know, the psychological present is said to be about three seconds long; that means that, you know, in a life there are about 600 million of them; in a month, there are about 600,000 -- most of them don't leave a trace. Most of them are completely ignored by the remembering self. And yet, somehow you get the sense that they should count, that what happens during these moments of experience is our life. It's the finite resource that we're spending while we're on this earth. And how to spend it would seem to be relevant, but that is not the story that the remembering self keeps for us.

So we have the remembering self and the experiencing self, and they're really quite distinct. The biggest difference between them is in the handling of time. From the point of view of the experiencing self, if you have a vacation, and the second week is just as good as the first, then the two-week vacation is twice as good as the one-week vacation. That's not the way it works at all for the remembering self. For the remembering self, a two-week vacation is barely better than the one-week vacation because there are no new memories added. You have not changed the story. And in this way, time is actually the critical variable that distinguishes a remembering self from an experiencing self; time has very little impact on the story.

Now, the remembering self does more than remember and tell stories. It is actually the one that makes decisions because, if you have a patient who has had, say,two colonoscopies with two different surgeons and is deciding which of them to choose, then the one that chooses is the one that has the memory that is less bad, and that's the surgeon that will be chosen. The experiencing self has no voice in this choice. We actually don't choose between experiences, we choose between memories of experiences. And even when we think about the future, we don't think of our future normally as experiences. We think of our future as anticipated memories. And basically you can look at this, you know, as a tyranny of the remembering self, and you can think of the remembering self sort of dragging the experiencing self through experiences that the experiencing self doesn't need.

I have that sense that when we go on vacations this is very frequently the case; that is, we go on vacations, to a very large extent, in the service of our remembering self. And this is a bit hard to justify I think. I mean, how much do we consume our memories? That is one of the explanations that is given for the dominance of the remembering self. And when I think about that, I think about a vacation we had in Antarctica a few years ago, which was clearly the best vacation I've ever had, and I think of it relatively often, relative to how much I think of other vacations. And I probably have consumed my memories of that three-week trip, I would say, for about 25 minutes in the last four years. Now, if I had ever opened the folder with the 600 pictures in it, I would have spent another hour. Now, that is three weeks, and that is at most an hour and a half. There seems to be a discrepancy. Now, I may be a bit extreme, you know, in how little appetite I have for consuming memories, but even if you do more of this, there is a genuine question: Why do we put so much weight on memory relative to the weight that we put on experiences?

So I want you to think about a thought experiment. Imagine that for your next vacation, you know that at the end of the vacation all your pictures will be destroyed, and you'll get an amnesic drug so that you won't remember anything. Now, would you choose the same vacation? (Laughter) And if you would choose a different vacation, there is a conflict between your two selves, and you need to think about how to adjudicate that conflict, and it's actually not at all obvious, because if you think in terms of time, then you get one answer, and if you think in terms of memories, you might get another answer. Why do we pick the vacations we do is a problem that confronts us with a choice between the two selves.

Now, the two selves bring up two notions of happiness. There are really two concepts of happiness that we can apply,one per self. So you can ask: How happy is the experiencing self? And then you would ask: How happy are the moments in the experiencing self's life? And they're all -- happiness for moments is a fairly complicated process. What are the emotions that can be measured? And, by the way, now we are capable of getting a pretty good idea of the happiness of the experiencing self over time. If you ask for the happiness of the remembering self, it's a completely different thing. This is not about how happily a person lives. It is about how satisfied or pleased the person is when that person thinks about her life. Very different notion. Anyone who doesn't distinguish those notions is going to mess up the study of happiness, and I belong to a crowd of students of well-being, who've been messing up the study of happiness for a long time in precisely this way.

The distinction between the happiness of the experiencing self and the satisfaction of the remembering self has been recognized in recent years, and there are now efforts to measure the two separately. The Gallup Organization has a world poll where more than half a million people have been asked questions about what they think of their life and about their experiences, and there have been other efforts along those lines. So in recent years, we have begun to learn about the happiness of the two selves. And the main lesson I think that we have learned is they are really different. You can know how satisfied somebody is with their life, and that really doesn't teach you much about how happily they're living their life, and vice versa. Just to give you a sense of the correlation, the correlation is about .5. What that means is if you met somebody, and you were told, "Oh his father is six feet tall," how much would you know about his height? Well, you would know something about his height, but there's a lot of uncertainty. You have that much uncertainty. If I tell you that somebody ranked their life eight on a scale of ten, you have a lot of uncertainty about how happy they are with their experiencing self. So the correlation is low.

We know something about what controls satisfaction of the happiness self. We know that money is very important, goals are very important. We know that happiness is mainly being satisfied with people that we like, spending time with people that we like. There are other pleasures, but this is dominant. So if you want to maximize the happiness of the two selves, you are going to end up doing very different things. The bottom line of what I've said here is that we really should not think of happiness as a substitute for well-being. It is a completely different notion.

Now, very quickly, another reason we can not think straight about happiness is that we do not attend to the same things when we think about life, and we actually live. So, if you ask the simple question of how happy people are in California, you are not going to get to the correct answer. When you ask that question, you think people must be happier in California if, say, you live in Ohio. (Laughter) And what happens is when you think about living in California, you are thinking of the contrast between California and other places, and that contrast, say, is in climate. Well, it turns out that climate is not very important to the experiencing self and it's not even very important to the reflective self that decides how happy people are. But now, because the reflective self is in charge, you may end up -- some people may end up moving to California. And it's sort of interesting to trace what is going to happen to people who move to California in the hope of getting happier. Well, their experiencing self is not going to get happier. We know that. But one thing will happen: They will think they are happier, because, when they think about it, they'll be reminded of how horrible the weather was in Ohio, and they will feel they made the right decision.

It is very difficult to think straight about well-being, and I hope I have given you a sense of how difficult it is.

Thank you.

(Applause)

Chris Anderson: Thank you. I've got a question for you. Thank you so much. Now, when we were on the phone a few weeks ago, you mentioned to me that there was quite an interesting result came out of that Gallup survey. Is that something you can share since you do have a few moments left now?

Daniel Kahneman: Sure. I think the most interesting result that we found in the Gallup survey is a number, which we absolutely did not expect to find. We found that with respect to the happiness of the experiencing self. When we looked at how feelings, vary with income. And it turns out that, below an income of 60,000 dollars a year, for Americans -- and that's a very large sample of Americans, like 600,000, so it's a large representative sample -- below an income of 600,000 dollars a year ...

CA: 60,000.

DK: 60,000. (Laughter) 60,000 dollars a year, people are unhappy, and they get progressively unhappier the poorer they get. Above that, we get an absolutely flat line. I mean I've rarely seen lines so flat. Clearly, what is happening is money does not buy you experiential happiness, but lack of money certainly buys you misery, and we can measure that misery very, very clearly. In terms of the other self, the remembering self, you get a different story. The more money you earn, the more satisfied you are. That does not hold for emotions.

CA: But Danny, the whole American endeavor is about life, liberty, the pursuit of happiness. If people took seriously that finding, I mean, it seems to turn upside down everything we believe about, like for example, taxation policy and so forth. Is there any chance that politicians, that the country generally, would take a finding like that seriously and run public policy based on it?

DK: You know I think that there is recognition of the role of happiness research in public policy. The recognition is going to be slow in the United States, no question about that, but in the U.K., it is happening, and in other countries it is happening. People are recognizing that they ought to be thinking of happiness when they think of public policy. It's going to take a while, and people are going to debate whether they want to study experience happiness, or whether they want to study life evaluation, so we need to have that debate fairly soon. How to enhance happiness goes very different ways depending on how you think, and whether you think of the remembering self or you think of the experiencing self. This is going to influence policy, I think, in years to come. In the United States, efforts are being made to measure the experience happiness of the population. This is going to be, I think, within the next decade or two, part of national statistics.

CA: Well, it seems to me that this issue will -- or at least should be -- the most interesting policy discussion to track over the next few years. Thank you so much for inventing behavioral economics. Thank you, Danny Kahneman.