Placeholder Image

Subtitles section Play video

  • I'll tell you a little bit about irrational behavior.

  • Not yours, of course -- other people's.

  • (Laughter)

  • So after being at MIT for a few years,

  • I realized that writing academic papers is not that exciting.

  • You know, I don't know how many of those you read,

  • but it's not fun to read and often not fun to write --

  • even worse to write.

  • So I decided to try and write something more fun.

  • And I came up with an idea that I will write a cookbook.

  • And the title for my cookbook was going to be

  • "Dining Without Crumbs: The Art of Eating Over the Sink."

  • (Laughter)

  • And it was going to be a look at life through the kitchen.

  • And I was quite excited about this. I was going to talk

  • a little bit about research, a little bit about the kitchen.

  • You know, we do so much in the kitchen I thought this would be interesting.

  • And I wrote a couple of chapters.

  • And I took it to MIT press and they said,

  • "Cute, but not for us. Go and find somebody else."

  • I tried other people and everybody said the same thing,

  • "Cute. Not for us."

  • Until somebody said,

  • "Look, if you're serious about this,

  • you first have to write a book about your research. You have to publish something,

  • and then you'll get the opportunity to write something else.

  • If you really want to do it you have to do it."

  • So I said, "You know, I really don't want to write about my research.

  • I do this all day long. I want to write something else.

  • Something a bit more free, less constrained."

  • And this person was very forceful and said,

  • "Look. That's the only way you'll ever do it."

  • So I said, "Okay, if I have to do it -- "

  • I had a sabbatical. I said, "I'll write about my research

  • if there is no other way. And then I'll get to do my cookbook."

  • So I wrote a book on my research.

  • And it turned out to be quite fun in two ways.

  • First of all, I enjoyed writing.

  • But the more interesting thing was that

  • I started learning from people.

  • It's a fantastic time to write,

  • because there is so much feedback you can get from people.

  • People write me about their personal experience,

  • and about their examples, and what they disagree,

  • and nuances.

  • And even being here -- I mean the last few days,

  • I've known really heights of obsessive behavior

  • I never thought about.

  • (Laughter)

  • Which I think is just fascinating.

  • I will tell you a little bit about irrational behavior.

  • And I want to start by giving you some examples of visual illusion

  • as a metaphor for rationality.

  • So think about these two tables.

  • And you must have seen this illusion.

  • If I asked you what's longer, the vertical line on the table on the left,

  • or the horizontal line on the table on the right?

  • Which one seems longer?

  • Can anybody see anything but the left one being longer?

  • No, right? It's impossible.

  • But the nice thing about visual illusion is we can easily demonstrate mistakes.

  • So I can put some lines on; it doesn't help.

  • I can animate the lines.

  • And to the extent you believe I didn't shrink the lines,

  • which I didn't, I've proven to you that your eyes were deceiving you.

  • Now, the interesting thing about this

  • is when I take the lines away,

  • it's as if you haven't learned anything in the last minute.

  • (Laughter)

  • You can't look at this and say, "Okay now I see reality as it is."

  • Right? It's impossible to overcome this

  • sense that this is indeed longer.

  • Our intuition is really fooling us in a repeatable, predictable, consistent way.

  • And there is almost nothing we can do about it,

  • aside from taking a ruler and starting to measure it.

  • Here is another one -- this is one of my favorite illusions.

  • What do you see the color that top arrow is pointing to?

  • Brown. Thank you.

  • The bottom one? Yellow.

  • Turns out they're identical.

  • Can anybody see them as identical?

  • Very very hard.

  • I can cover the rest of the cube up.

  • And if I cover the rest of the cube you can see that they are identical.

  • And if you don't believe me you can get the slide later

  • and do some arts and crafts and see that they're identical.

  • But again it's the same story

  • that if we take the background away,

  • the illusion comes back. Right.

  • There is no way for us not to see this illusion.

  • I guess maybe if you're colorblind I don't think you can see that.

  • I want you to think about illusion as a metaphor.

  • Vision is one of the best things we do.

  • We have a huge part of our brain dedicated to vision --

  • bigger than dedicated to anything else.

  • We do more vision more hours of the day than we do anything else.

  • And we are evolutionarily designed to do vision.

  • And if we have these predictable repeatable mistakes in vision,

  • which we're so good at,

  • what's the chance that we don't make even more mistakes

  • in something we're not as good at --

  • for example, financial decision making:

  • (Laughter)

  • something we don't have an evolutionary reason to do,

  • we don't have a specialized part of the brain,

  • and we don't do that many hours of the day.

  • And the argument is in those cases

  • it might be the issue that we actually make many more mistakes

  • and, worse, not have an easy way to see them.

  • Because in visual illusions we can easily demonstrate the mistakes;

  • in cognitive illusion it's much, much harder

  • to demonstrate to people the mistakes.

  • So I want to show you some cognitive illusions,

  • or decision-making illusions, in the same way.

  • And this is one of my favorite plots in social sciences.

  • It's from a paper by Johnson and Goldstein.

  • And it basically shows

  • the percentage of people who indicated

  • they would be interested in giving their organs to donation.

  • And these are different countries in Europe. And you basically

  • see two types of countries:

  • countries on the right, that seem to be giving a lot;

  • and countries on the left that seem to giving very little,

  • or much less.

  • The question is, why? Why do some countries give a lot

  • and some countries give a little?

  • When you ask people this question,

  • they usually think that it has to be something about culture.

  • Right? How much do you care about people?

  • Giving your organs to somebody else

  • is probably about how much you care about society, how linked you are.

  • Or maybe it is about religion.

  • But, if you look at this plot,

  • you can see that countries that we think about as very similar

  • actually exhibit very different behavior.

  • For example, Sweden is all the way on the right,

  • and Denmark, that we think is culturally very similar,

  • is all the way on the left.

  • Germany is on the left. And Austria is on the right.

  • The Netherlands is on the left. And Belgium is on the right.

  • And finally, depending on your particular version

  • of European similarity,

  • you can think about the U.K and France as either similar culturally or not.

  • But it turns out that from organ donation they are very different.

  • By the way, the Netherlands is an interesting story.

  • You see the Netherlands is kind of the biggest of the small group.

  • Turns out that they got to 28 percent

  • after mailing every household in the country a letter

  • begging people to join this organ donation program.

  • You know the expression, "Begging only gets you so far"?

  • It's 28 percent in organ donation.

  • (Laughter)

  • But whatever the countries on the right are doing

  • they are doing a much better job than begging.

  • So what are they doing?

  • Turns out the secret has to do with a form at the DMV.

  • And here is the story.

  • The countries on the left have a form at the DMV

  • that looks something like this.

  • Check the box below if you want to participate

  • in the organ donor program.

  • And what happens?

  • People don't check, and they don't join.

  • The countries on the right, the ones that give a lot,

  • have a slightly different form.

  • It says check the box below if you don't want to participate.

  • Interestingly enough, when people get this,

  • they again don't check -- but now they join.

  • (Laughter)

  • Now think about what this means.

  • We wake up in the morning and we feel we make decisions.

  • We wake up in the morning and we open the closet

  • and we feel that we decide what to wear.

  • And we open the refrigerator and we feel that we decide what to eat.

  • What this is actually saying is that

  • much of these decisions are not residing within us.

  • They are residing in the person who is designing that form.

  • When you walk into the DMV,

  • the person who designed the form will have a huge influence

  • on what you'll end up doing.

  • Now it's also very hard to intuit these results. Think about it for yourself.

  • How many of you believe

  • that if you went to renew your license tomorrow,

  • and you went to the DMV,

  • and you would encounter one of these forms,

  • that it would actually change your own behavior?

  • Very, very hard to think that you will influence us.

  • We can say, "Oh, these funny Europeans, of course it would influence them."

  • But when it comes to us,

  • we have such a feeling that we are at the driver's seat,

  • we have such a feeling that we are in control,

  • and we are making the decision,

  • that it's very hard to even accept

  • the idea that we actually have

  • an illusion of making a decision, rather than an actual decision.

  • Now, you might say,

  • "These are decisions we don't care about."

  • In fact, by definition, these are decisions

  • about something that will happen to us after we die.

  • How could we care about something less

  • than something that happens after we die?

  • So a standard economist, someone who believes in rationality,

  • would say, "You know what? The cost of lifting the pencil

  • and marking a V is higher than the possible

  • benefit of the decision,

  • so that's why we get this effect."

  • But, in fact, it's not because it's easy.

  • It's not because it's trivial. It's not because we don't care.

  • It's the opposite. It's because we care.

  • It's difficult and it's complex.

  • And it's so complex that we don't know what to do.

  • And because we have no idea what to do

  • we just pick whatever it was that was chosen for us.

  • I'll give you one more example for this.

  • This is from a paper by Redelmeier and Schaefer.

  • And they said, "Well, this effect also happens to experts,

  • people who are well-paid, experts in their decisions,

  • do it a lot."

  • And they basically took a group of physicians.

  • And they presented to them a case study of a patient.

  • Here is a patient. He is a 67-year-old farmer.

  • He's been suffering from a right hip pain for a while.

  • And then they said to the physician,

  • "You decided a few weeks ago

  • that nothing is working for this patient.

  • All these medications, nothing seems to be working.

  • So you refer the patient to hip replacement therapy.

  • Hip replacement. Okay?"

  • So the patient is on a path to have his hip replaced.

  • And then they said to half the physicians, they said,

  • "Yesterday you reviewed the patient's case

  • and you realized that you forgot to try one medication.

  • You did not try ibuprofen.

  • What do you do? Do you pull the patient back and try ibuprofen?

  • Or do you let them go and have hip replacement?"

  • Well the good news is that most physicians in this case

  • decided to pull the patient and try the ibuprofen.

  • Very good for the physicians.

  • The other group of the physicians, they said,

  • "Yesterday when you reviewed the case

  • you discovered there were two medications you didn't try out yet,

  • ibuprofen and piroxicam."

  • And they said, "You have two medications you didn't try out yet. What do you do?

  • You let them go. Or you pull them back.

  • And if you pull them back do you try ibuprofen or piroxicam? Which one?"

  • Now think of it. This decision

  • makes it as easy to let the patient continue with hip replacement.

  • But pulling them back, all of the sudden becomes more complex.

  • There is one more decision.

  • What happens now?

  • Majority of the physicians now choose to let the patient go

  • to hip replacement.

  • I hope this worries you, by the way --

  • (Laughter)