GUY RAZ, HOST:
It's the TED Radio Hour from NPR. I'm Guy Raz. And on the show today - shifting time, ideas about how we perceive and think about time. And do you remember when you were a kid how a day at school felt like forever? And then at a certain point in your life, as you get older, the days and the months just seem to move faster.
DAN GILBERT: Yes, they do.
RAZ: This is Dan Gilbert, Harvard psychologist.
GILBERT: And that's because older and younger people don't actually experience time all that differently, they just remember it very differently. When old people say time goes by so fast, they're talking about the time that's already gone by. There's also just a whole hell of a lot more recording in the brain of an 86-year-old person. When they're thinking about life, they're thinking across much greater expanses of time. And so to traverse that many years in five seconds versus traversing five or six years in five seconds, you get the sense that you're going a lot faster.
RAZ: Which makes sense when you think about it, but it still doesn't explain why we tend to think of ourselves as fixed in time depending on where we are in life.
GILBERT: When I turned 21, I thought, I'm finally grown up. And then when I turned 30, I thought, no, now I'm grown-up. Boy, was I crazy about that when I was 21.
GILBERT: I repeated that when I was 40 and then when I was 50. And the amazing thing is that each time it happens, I'm pretty sure I'm right this time, despite the fact that I was wrong every other time.
RAZ: So a 30-year-old would say, yeah, I'm different from the person I was when I was 20, but I'm now the person I am. And a 40-year-old would say, yeah, I'm different from who I was when I was 30, but I finally figured out who I am - and go on and so on and so forth.
GILBERT: Not only that but the same person says that thing over and over again. Look, we all know we will change. We know that we're going to gain a few pounds and get a few wrinkles. But we think that fundamentally the people we've become - our personalities, our values, our preferences, likes and dislikes - will remain relatively stable in the future. And in that, we are wrong.
RAZ: Dan and other psychologists have tested this by taking a group of people of a certain age...
GILBERT: And you ask them how much they're going to change in the next 10 years. Then you find a group of people who are 10 years older, and you ask them how much they changed in the last 10 years. I can ask you questions like, on a scale of 1 to 10, how extroverted are you now? How extroverted do you think you'll be in 10 years? How extroverted were you 10 years ago? Now, if everyone is perfectly rational and everyone has perfect memory, those two numbers should match. What we found is no matter what the dimension of change and no matter how old the people were, those numbers never matched.
RAZ: Dan explained why that is on the TED stage.
(SOUNDBITE OF TED TALK)
GILBERT: All of us are walking around with an illusion, an illusion that history, our personal history, has just come to an end. We call this the end of history illusion. An illusion that we have just recently become the people that we were always meant to be and will be for the rest of our lives. At every age, people underestimate how much their personalities will change in the next decade. And it isn't just ephemeral things like values and personality. You can ask people about their likes and dislikes, their basic preferences. For example, name your best friend, your favorite kind of vacation. What's your favorite hobby? What's your favorite kind of music? People can name these things. We ask half of them to tell us, do you think that that will change over the next 10 years and half of them to tell us, did that change over the last 10 years. People predict that the friend they have now is the friend they'll have in 10 years, the vacation they most enjoy now is the one they'll enjoy in ten years. And yet people who are 10 years older all say, you know, that's really changed.
RAZ: Does it matter which decade of life we're talking about?
GILBERT: The amount of change between 20 and 30 is greater than the amount of change between 30 and 40. The pace of change does indeed slow as we age. All of us have the sense that we're coming into our own, that we're finally becoming the person we were meant to be.
GILBERT: That's not entirely wrong. You will change less in the future than you did in the past, but you will change more in the future than you expect to.
RAZ: What explains that? I mean, why are we so bad at imagining how we will change over time?
GILBERT: We don't really know, but we have some good guesses. The best guess to date is that when you try to imagine yourself in the future, you can imagine changing in one direction as easily as you can imagine changing in the other. As a result of it being easy for you to imagine becoming more extroverted and to imagine becoming less extroverted, you mistakenly conclude that you won't change at all. But this is a mistake. I mean, imagine I frame the problem differently. You're walking down a road and you come to a dead end. Will you turn left or right? Well, I can imagine turning left. I can imagine turning right. That's fine. Would you conclude that as a result of not knowing which way you're going to turn, you won't turn at all? Of course not. And that problem you see that just because you don't know the direction of your turn doesn't mean turning is unlikely. And yet somehow as we move through time, because we can't predict exactly who we will be, we mistakenly take that to mean we will remain the person we are.
RAZ: What do you think is helpful about having this illusion that we have just become the person that we were always meant to be? Is there, like, a reason why we feel that way?
GILBERT: Well, we certainly don't know that there is something helpful about it. Every psychological tendency doesn't have to have a benefit.
GILBERT: But if you asked me to guess what benefit might accrue to people who believe that the amount of change in front of them is quite limited, most people are fundamentally satisfied with who they are. They feel that they've finally arrived at being a pretty good person, a pretty capable person, a pretty responsible person. And as a result, the idea that any of these things might change feels a little threatening, a little undermining. So I think stasis is a comfortable illusion that all of us live with. And it might be one of the reasons why we don't believe there's as much change in the future as we're going to find out there really was.
RAZ: So based on all the evidence that you've seen, can you sort of come up with a rough age where most people are actually coming into the person they were always meant to be?
GILBERT: Fifty-seven (laughter).
RAZ: I got it, which happens to be your age, right?
GILBERT: Now, if you ask me next year, I might have a different opinion.
(SOUNDBITE OF TED TALK)
GILBERT: The bottom line is time is a powerful force. It transforms our preferences. It reshapes our values. It alters our personalities. We seem to appreciate this fact but only in retrospect. Only when we look backwards do we realize how much change happens in a decade. It's as if for most of us the present is a magic time. It's a watershed on the timeline. It's the moment at which we finally become ourselves. Human beings are works in progress that mistakenly think they're finished. The person you are right now is as transient, as fleeting and as temporary as all the people you've ever been. The one constant in our life is change.
RAZ: I mean, it really is amazing that something like time, which seems so fixed, can be experienced in so many different ways depending on where you are in life.
GILBERT: You know, the human brain just doesn't know how to think about time. If you ask most people, what's real, the present, the past or the future? They say the present.
GILBERT: Actually they're wrong. The past and the future are both real. The present is a psychological illusion. The present is just the wall between yesterday and today. You know, if you go to the beach, you see water and you see sand, and it looks like there's a line between them, but that line is not a third thing. There's only water, and there's only sand. Similarly, all moments in time are either in the past or in the future...
GILBERT: ...Which is to say the present doesn't exist.
RAZ: Psychologist Dan Gilbert teaches at Harvard. He's got lots more TED Talks that are all amazing. You can see them at ted.com.
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