1 00:00:00,006 --> 00:00:02,593 Hello. Hello. 2 00:00:02,593 --> 00:00:06,977 In this section, we're going to talk about irrationality. 3 00:00:06,978 --> 00:00:12,283 There's a little story that a father calls his son and says, son, after 30 years of 4 00:00:12,283 --> 00:00:16,197 marriage, your mother and I just decided to get divorced. 5 00:00:16,198 --> 00:00:18,350 And the son he say, well this is terrible. This is awful. 6 00:00:18,350 --> 00:00:22,725 I really don't want you to do it. The, the son says, you know what? 7 00:00:22,726 --> 00:00:25,050 I'll come home. Just, just don't do it yet. 8 00:00:25,050 --> 00:00:26,720 Let's talk about it. He says, you know what? 9 00:00:26,720 --> 00:00:29,880 I'll call my sister. We'll be there the day after tomorrow. 10 00:00:29,880 --> 00:00:33,880 Just don't do anything until we have a discussion with you and Mom. 11 00:00:33,880 --> 00:00:36,047 And the father said, you know what? I promise you. 12 00:00:36,048 --> 00:00:38,348 We'll wait. We'll see you the day after tomorrow, and 13 00:00:38,348 --> 00:00:42,110 then we'll have a discussion. He puts down the phone. 14 00:00:42,110 --> 00:00:46,257 He turns to his wife. And he says, darling, this year the kids 15 00:00:46,257 --> 00:00:50,811 are going to come home for the holidays, and they're paying for their own flight 16 00:00:50,811 --> 00:00:55,145 tickets[MUSIC]. So when we think about irrationality, what 17 00:00:55,145 --> 00:00:57,930 is it about? It's about the forces that drive our 18 00:00:57,930 --> 00:01:01,586 behavior. Some it are economic forces and some if it 19 00:01:01,586 --> 00:01:05,169 are social forces. And in this particular section we are 20 00:01:05,169 --> 00:01:08,957 going to look at all kinds of influences on our behavior. 21 00:01:08,958 --> 00:01:11,120 We're also going to look at choice architecture. 22 00:01:11,120 --> 00:01:15,254 We're going to look at how the world around us and how it's structured. 23 00:01:15,255 --> 00:01:18,486 Changes how we view things and how we make decisions. 24 00:01:18,487 --> 00:01:22,448 We're going to look at how initial decisions are going to have long-term 25 00:01:22,448 --> 00:01:26,606 influence on us, and finally we're going to think about what we could do to do 26 00:01:26,606 --> 00:01:30,534 things better. What can we do to try to overcome some of 27 00:01:30,534 --> 00:01:56,452 our irrational tendencies. I would like to argue, that when we think 28 00:01:56,452 --> 00:02:10,740 about irrational behavior. This is something that is important, both 29 00:02:10,740 --> 00:02:13,300 for our personal life, as well as our social life. 30 00:02:13,300 --> 00:02:16,567 And as well as for our work life and, of course, for policy. 31 00:02:16,568 --> 00:02:20,184 And to get us started thinking about it, I would like to tell you my own eh, personal 32 00:02:20,184 --> 00:02:24,976 case and how I became interested in. When and under what conditions we behave 33 00:02:24,976 --> 00:02:28,385 irrationally. So as you can probably tell I was badly 34 00:02:28,385 --> 00:02:32,630 injured many years ago. I was burned on about 70% of my body and I 35 00:02:32,630 --> 00:02:37,784 spent about three years in hospital. And hospitals give, gives everybody, 36 00:02:37,784 --> 00:02:42,866 everybody who spends time there many opportunities to examine and think about 37 00:02:42,866 --> 00:02:46,674 irrational behaviors. And in my particular case there were lots 38 00:02:46,674 --> 00:02:49,452 of examples. But the thing that focused all my 39 00:02:49,452 --> 00:02:54,468 attention, the thing that kind of eh, made me think every day was the question of 40 00:02:54,468 --> 00:02:57,500 bandage removal. So consider the following question. 41 00:02:57,500 --> 00:03:01,468 Imagine you were, like me, burned in 70% of your body and you were covered with 42 00:03:01,468 --> 00:03:05,144 bandages, and every day the nurses had to remove your bandages. 43 00:03:05,145 --> 00:03:08,897 And ask yourself what is the right way to remove these bandages? 44 00:03:08,898 --> 00:03:11,330 And we can think about two very distinct strategies. 45 00:03:11,330 --> 00:03:16,720 One is to rip the bandages off, quickly as possible, one after the other, minimizing 46 00:03:16,720 --> 00:03:21,823 the duration of the treatment but making each second of it incredibly painful. 47 00:03:21,824 --> 00:03:24,604 The second approach is to rip the bandages off slowly. 48 00:03:24,605 --> 00:03:29,097 Take a long time but make each second less painful. 49 00:03:29,098 --> 00:03:34,672 Consider to yourself, which one of those strategies would you pick? 50 00:03:34,672 --> 00:03:38,510 Which one? When I talk to people about this most 51 00:03:38,510 --> 00:03:43,054 people say they would prefer the ripping approach, and that's actually the approach 52 00:03:43,054 --> 00:03:46,238 my nurses liked as well. I always, by the way, thought that the 53 00:03:46,238 --> 00:03:50,240 reason they had this intuition that this is a better approach is because that's how 54 00:03:50,240 --> 00:03:53,685 they use to wax their legs. Kind of in the ripping version. 55 00:03:53,685 --> 00:03:57,604 But, removing hair is not the same as removing bandages necessarily. 56 00:03:57,604 --> 00:04:02,240 So, which one is the right approach? As a patient, I used to feel that they 57 00:04:02,240 --> 00:04:06,268 were not doing the right thing. I used to argue with them and plead with 58 00:04:06,268 --> 00:04:10,428 them and say, please, take more time, make it slower, don't take, don't rip the 59 00:04:10,428 --> 00:04:13,300 bandages as fast, but the nurses told me two things. 60 00:04:13,300 --> 00:04:16,130 The first they, they said was that they were right. 61 00:04:16,130 --> 00:04:20,166 They knew what is the best thing to do, what would minimize my pain, right? 62 00:04:20,166 --> 00:04:25,897 In some sense, they said, who are you, the patient, to question our eh, judgement as 63 00:04:25,897 --> 00:04:28,976 professionals. And the second thing they said was that 64 00:04:28,976 --> 00:04:32,770 the word patient doesn't mean to butt in, or intervene, or make suggestions. 65 00:04:32,770 --> 00:04:37,131 It means to be passive and just sit there eh, patiently. 66 00:04:37,132 --> 00:04:41,656 In fact this was in Israel where I grew up, but the word patient has this passive 67 00:04:41,656 --> 00:04:44,174 component in any language I've seen so far. 68 00:04:44,174 --> 00:04:48,910 So the nurses kept on doing what they thought was the best thing to do which was 69 00:04:48,910 --> 00:04:53,720 to rip the bandages off quickly, and I kept on complaining, and we kept on these 70 00:04:53,720 --> 00:04:57,322 roles for quite a long time. About three years later when I left the 71 00:04:57,322 --> 00:05:00,514 hospital, I started studying at the university, and one of the first 72 00:05:00,514 --> 00:05:04,342 interesting lessons I learned was about the power of the experimental method. 73 00:05:04,343 --> 00:05:09,038 And what I particularly found interesting is the idea that if you have a question, 74 00:05:09,038 --> 00:05:12,687 about almost anything in life, you can posit to an experiment. 75 00:05:12,688 --> 00:05:15,750 You can say here is one version, here's another version. 76 00:05:15,750 --> 00:05:19,910 Let's see which one wins. So I decided to try this out. 77 00:05:19,910 --> 00:05:24,667 Now if you think about it, this question about how people aggregate information 78 00:05:24,667 --> 00:05:27,510 over time is very general. Imagine that you have an axis. 79 00:05:27,510 --> 00:05:31,930 You have time, and you have intensity, and you have experience that can vary in 80 00:05:31,930 --> 00:05:35,130 intensity in all kinds of ways. You can have movies. 81 00:05:35,131 --> 00:05:38,363 What could happen if we had a movie and we had really good 5 minutes. 82 00:05:38,364 --> 00:05:41,447 Are they better off in the beginning, the middle or the end? 83 00:05:41,448 --> 00:05:46,234 What if we can take an opera or a concert and make it 10% longer or half an hour 84 00:05:46,234 --> 00:05:49,107 longer, are we making it better by how much? 85 00:05:49,108 --> 00:05:53,404 So these questions of how people take an experience vary over time, and aggregate 86 00:05:53,404 --> 00:05:58,200 information is actually quite general. But for me, the main issue was pain. 87 00:05:58,200 --> 00:06:02,397 I wanted to understand how this works in the domain of pain. 88 00:06:02,398 --> 00:06:06,899 So initially, I didn't have much money for research, so I went to a hardware store 89 00:06:06,899 --> 00:06:10,547 and I bought a carpenter's vise, basically something like this. 90 00:06:10,548 --> 00:06:14,580 And I set up this carpenter's vise in the lab, and I invited people to come into the 91 00:06:14,580 --> 00:06:18,660 lab and put two fingers in this device and I would crunch people's fingers a little 92 00:06:18,660 --> 00:06:20,972 bit. And I would crunch their fingers a little 93 00:06:20,972 --> 00:06:24,220 bit for long durations and short durations, high intensity and low 94 00:06:24,220 --> 00:06:26,983 intensity. Pain that goes up, pain that goes down, up 95 00:06:26,983 --> 00:06:29,680 and down, down and up, all kinds of versions of pain. 96 00:06:29,680 --> 00:06:35,509 And after each of those painful experience I would ask people and how painful was 97 00:06:35,509 --> 00:06:40,142 that, and how painful was that. This is kind of just rating scale from not 98 00:06:40,142 --> 00:06:42,920 painful at all to the most painful I can imagine. 99 00:06:42,920 --> 00:06:47,210 And then we ask people to make choices, which one of the last 2 experiences would 100 00:06:47,210 --> 00:06:51,370 you last to repeat, would you like to repeat again, the last one or the one just 101 00:06:51,370 --> 00:06:54,675 before it? And people gave me their choices and their 102 00:06:54,675 --> 00:06:59,378 ratings, and I were trying to infer how people combine these experiences. 103 00:06:59,378 --> 00:07:04,466 And I finished the first paper, I learned some lessons, I published these in 104 00:07:04,466 --> 00:07:07,528 academic journal. And then good things happened, I got more 105 00:07:07,528 --> 00:07:10,129 money for research, so I moved to better equipment. 106 00:07:10,130 --> 00:07:15,704 I move to something like this which are a mechanism to create annoying sound, in 107 00:07:15,704 --> 00:07:19,395 different intensities. I did experiments with electrical shocks 108 00:07:19,395 --> 00:07:22,127 over time. I even created a pain suit. 109 00:07:22,128 --> 00:07:25,720 I created a suit with 300 feet of hoses stitched thorough it. 110 00:07:25,720 --> 00:07:30,618 And with this suit, I could get people to be very hot and very cold, and then I 111 00:07:30,618 --> 00:07:33,797 could relieve that pain in many different ways. 112 00:07:33,798 --> 00:07:38,190 And what did I learn from all of those experiences and all of those experiments? 113 00:07:38,190 --> 00:07:42,837 I learned that the nurses got things wrong in multiple ways. 114 00:07:42,838 --> 00:07:48,025 First of all in the terms of the question of duration versus intensity, it turns out 115 00:07:48,025 --> 00:07:53,050 that if you take an experience and make it twice as long, you don't make it twice as 116 00:07:53,050 --> 00:07:55,988 painful. So the nurses were trying to minimize the 117 00:07:55,988 --> 00:07:58,840 duration, but they were not doing the right thing. 118 00:07:58,840 --> 00:08:02,431 On the other hand, when you play with the intensity, you make something more 119 00:08:02,431 --> 00:08:05,258 intense. Now you're really changing how people 120 00:08:05,258 --> 00:08:08,279 experience it. So what the nurses were doing, they were 121 00:08:08,279 --> 00:08:12,122 trying to minimize the duration at the cost of the intensity, but by doing so 122 00:08:12,122 --> 00:08:15,790 they were not saving me much, but they were making it much more painful. 123 00:08:15,790 --> 00:08:18,817 And not just for me, by the way, for all the other patients. 124 00:08:18,818 --> 00:08:22,850 The second thing the nurses failed to understand was that progression over time 125 00:08:22,850 --> 00:08:26,435 matters a great deal. When you start with the low pain, and you 126 00:08:26,435 --> 00:08:31,160 increase pain over time, this is much, much worse than starting with the high 127 00:08:31,160 --> 00:08:35,490 pain and going down over time, and mostly for reason of convenience. 128 00:08:35,490 --> 00:08:40,026 The nurses started at my legs, and ended up in my face, which gave me the wrong 129 00:08:40,026 --> 00:08:44,368 progression of pain over time. And, finally it turns out that for really 130 00:08:44,368 --> 00:08:48,557 long periods of pain it's good to give people a period to kind of recover 131 00:08:48,557 --> 00:08:52,414 recuperate and prepare themselves for the next period of pain. 132 00:08:52,414 --> 00:08:54,575 And, again this was something that the nurse did not. 133 00:08:54,576 --> 00:08:58,198 Get. Now when I finished doing these 134 00:08:58,198 --> 00:09:03,261 experiments about pain and pain perception, aggregation of pain, I went 135 00:09:03,261 --> 00:09:07,664 back and I talked to the nurses. All kinds of things have changed since 136 00:09:07,664 --> 00:09:11,751 then, but the thing that puzzled me the most was how could the nurses get it 137 00:09:11,751 --> 00:09:15,802 wrong. Here were kind people, wonderful people 138 00:09:15,802 --> 00:09:20,882 who were spending hours in terrible conditions to serve their patients. 139 00:09:20,882 --> 00:09:23,940 And they were not saying, you know, I don't know which is the right way. 140 00:09:23,940 --> 00:09:27,524 They were convinced that the right thing to do was actually the thing that was 141 00:09:27,524 --> 00:09:29,705 wrong. It's not as if they say, I just don't know 142 00:09:29,705 --> 00:09:33,799 what the right answer is. No they actually had a strong conviction 143 00:09:33,799 --> 00:09:38,827 that they knew waht the right answer is, but that was not the right one. 144 00:09:38,828 --> 00:09:42,616 And then of course the quesion is are nurses the only people who have the wrong 145 00:09:42,616 --> 00:09:45,212 intuition. Are nurses the only people that says this 146 00:09:45,212 --> 00:09:48,570 is what I think is the right answer when in fact it's the wrong answer. 147 00:09:48,570 --> 00:09:53,330 And from that point of view, and from that starting point, I started looking at all 148 00:09:53,330 --> 00:09:58,020 kinds of behaviors, all kinds of things in which we have good intuitions, we have 149 00:09:58,020 --> 00:10:02,990 good intentions, we trust our intuitions but in fact, our intuitions are misleading 150 00:10:02,990 --> 00:10:06,514 us time after time. And this is for me kind of the starting 151 00:10:06,514 --> 00:10:11,546 point of irrational behavior, things that we think we know how they work, we think 152 00:10:11,546 --> 00:10:15,320 we know what's the right thing to do, but in fact we're wrong. 153 00:10:15,320 --> 00:10:20,610 So let's think about some of this. Now to get you an intuitive example of how 154 00:10:20,610 --> 00:10:25,740 these things work, without inviting you to the lab and to eh, squish your fingers. 155 00:10:25,740 --> 00:10:29,637 I want us to think a little bit about visual illusions. 156 00:10:29,638 --> 00:10:34,284 So consider the following illusions. You have two Towers of Pisa here, one on 157 00:10:34,284 --> 00:10:38,070 the right and one on the left. And now think to yourself, which one leans 158 00:10:38,070 --> 00:10:44,060 more to the right? If you're like everybody else on the 159 00:10:44,060 --> 00:10:47,726 planet, you think that the one on the right is leaning more. 160 00:10:47,726 --> 00:10:53,028 But what about the following thing? Now, again, if I asked you the same 161 00:10:53,028 --> 00:10:59,058 question, again you would think the one on the right is the one leaning more to the 162 00:10:59,058 --> 00:11:01,964 right. Now of course they'll just switched in 163 00:11:01,964 --> 00:11:05,037 front of you and you know this is a visual illusion. 164 00:11:05,038 --> 00:11:09,327 Now what's interesting about visual illusions is that everybody gets it wrong. 165 00:11:09,328 --> 00:11:13,240 It doesn't matter how old you are, how young you are, it doesn't matter how much 166 00:11:13,240 --> 00:11:16,989 experience you have in vision, as long as you can see you will get it wrong. 167 00:11:18,190 --> 00:11:22,348 Here's another visual illusion, this is one of my favorite all-time visual 168 00:11:22,348 --> 00:11:26,502 illusions. Look at this cube, the top arrow, to what 169 00:11:26,502 --> 00:11:30,079 color is it pointing? You probably think it's about brown. 170 00:11:30,079 --> 00:11:34,431 What about the bottom one? Well, looks orangish. 171 00:11:34,431 --> 00:11:38,210 Turns out they are identical. Can any of you see them as identical? 172 00:11:38,210 --> 00:11:42,547 Of course not. Now what happens if I cover the cube up? 173 00:11:42,548 --> 00:11:47,048 Now you can see that both of those patches are actually identical, and by the way 174 00:11:47,048 --> 00:11:49,997 there's no trick to it, these are really identical. 175 00:11:49,998 --> 00:11:54,502 And here's the other interesting thing, now the illusion pops right back. 176 00:11:54,502 --> 00:11:58,865 Knowing that those two things are actually the same doesn't help you in any way to 177 00:11:58,865 --> 00:12:02,987 see them as identical. Now there's something else interesting in 178 00:12:02,987 --> 00:12:08,347 this illusion, which we'll come back to later, which is that this illusion is all 179 00:12:08,347 --> 00:12:11,501 about the way that the brain uses relativity. 180 00:12:11,502 --> 00:12:15,414 Many times what you think to yourself you're doing, is you're comparing the top 181 00:12:15,414 --> 00:12:19,190 patch to the bottom patch, but that's actually not what your visual system is 182 00:12:19,190 --> 00:12:21,306 doing. What the visual system is doing is 183 00:12:21,306 --> 00:12:25,522 comparing the top patch to its immediate environment and the bottom patch to it's 184 00:12:25,522 --> 00:12:29,050 immediate environment, and because of that you get this illusion. 185 00:12:29,050 --> 00:12:33,560 You think to yourself that you can compare both patches correctly, but you can't. 186 00:12:33,560 --> 00:12:38,510 When we come back to it you'll see how it comes about this illusion in all kinds of 187 00:12:38,510 --> 00:12:43,085 other areas of life, including pricing, for example, and how we're using 188 00:12:43,085 --> 00:12:48,387 background context to evaluate and think differently about what we're comparing. 189 00:12:48,388 --> 00:12:51,984 There's one more type of illusion I want to eh, share with you, and I'm going to 190 00:12:51,984 --> 00:12:56,082 show you a couple of examples of those. And it's a different kind of illusion 191 00:12:56,082 --> 00:12:58,847 because it only works once, so pay attention. 192 00:12:58,847 --> 00:13:03,010 So in the next clip, what you're going to see is a group of people holding iPads, 193 00:13:03,010 --> 00:13:07,177 and they're going to move the iPads, and the iPads are going to change colors. 194 00:13:07,178 --> 00:13:11,937 And your task is to count how many times they change into the color red. 195 00:13:11,938 --> 00:13:16,220 Every time something change from one color to red to something else, you count it and 196 00:13:16,220 --> 00:13:18,620 then another iPad changes to red, you count it. 197 00:13:18,620 --> 00:13:23,704 And your task is to count how many times all the iPads Across the whole clip, 198 00:13:23,704 --> 00:13:27,862 change into red colors. Now, don't get too technical, if something 199 00:13:27,862 --> 00:13:31,933 looks almost like red or slightly pinkish, it's okay, count it as red. 200 00:13:31,933 --> 00:13:34,938 Okay? So, before we go though, I do want to say 201 00:13:34,938 --> 00:13:38,451 a couple of things. First of all, it turns out that there's a 202 00:13:38,451 --> 00:13:42,867 lot of research about it, showing that people who do well on this task, people 203 00:13:42,867 --> 00:13:46,562 who count well on this task, do well in terms of their love life. 204 00:13:46,562 --> 00:13:51,571 They have better, better romantic life. And the second thing is the people who do 205 00:13:51,571 --> 00:13:55,390 well on these tasks, live longer. So if I were you, I'm just saying, if I 206 00:13:55,390 --> 00:14:00,354 were you I would focus, I would count well because remember what's on the line here 207 00:14:00,354 --> 00:14:03,117 is your romantic future and your longevity. 208 00:14:03,118 --> 00:14:09,430 So count carefully how many times the people, how many times the people, the 209 00:14:09,430 --> 00:14:15,180 iPads are switching into red color. Ready. 210 00:14:15,181 --> 00:14:18,612 Set. Go. 211 00:14:18,613 --> 00:15:11,058 [music] So how many did you count? Count 50, 60, 70, 40, 20? 212 00:15:11,059 --> 00:15:15,024 How many? The real number is 62 but the reality is 213 00:15:15,024 --> 00:15:19,688 that, that doesn't matter so much. The reason I really asked you this 214 00:15:19,688 --> 00:15:25,196 question was not to ask you how many times the iPads are flashing red, but to ask you 215 00:15:25,196 --> 00:15:30,461 a slightly different question which is, did you notice, me in a particular bee 216 00:15:30,461 --> 00:15:35,210 suit, hovering around the scene? Did you notice me at all, or not? 217 00:15:35,210 --> 00:15:38,334 Let's look at it again. And this time try to pay careful 218 00:15:38,334 --> 00:15:42,430 attention, not to the iPads, but to the total scene, and let's see if this time 219 00:15:42,430 --> 00:15:48,881 you can see me floating around. [music] And just to be clear, this is the 220 00:15:48,881 --> 00:15:52,520 same exact clip. And if you don't believe me, luckily you 221 00:15:52,520 --> 00:15:56,312 have the video. Go back and you can look at the first clip 222 00:15:56,312 --> 00:16:01,045 again just to prove it to yourself beyond a shadow of a doubt. 223 00:16:01,046 --> 00:16:37,089 [music] I hope, that like me, you find this quite startling. 224 00:16:37,090 --> 00:16:42,011 You look at a small part of the screen. You focus, you look very carefully, and 225 00:16:42,011 --> 00:16:47,324 nevertheless something unexpected happens around the screen, and you're able to 226 00:16:47,324 --> 00:16:50,266 ignore it. It's a tremendous ability of human, 227 00:16:50,267 --> 00:16:55,000 capacity and the reason for that by the way, is that we don't see with our eyes. 228 00:16:55,000 --> 00:16:58,655 We see with our brains. Our brains expected to see a particular 229 00:16:58,655 --> 00:17:02,950 pattern and that's what we end up seeing. Now we think we see with our eyes. 230 00:17:02,950 --> 00:17:06,180 We think that we observe all the information, but we don't. 231 00:17:06,180 --> 00:17:10,590 And just as another example of that, do you remember what shirt I was wearing 232 00:17:10,590 --> 00:17:14,262 before we started this clip? Well, you can go back and check for 233 00:17:14,262 --> 00:17:19,372 yourself, but I have a different hair cut, slightly different shave, actually very 234 00:17:19,372 --> 00:17:22,432 different shave. Well, slightly different shave, and a 235 00:17:22,432 --> 00:17:26,100 different shirt. And I bet you didn't notice those changes 236 00:17:26,100 --> 00:17:29,209 either. I hope you agree with me that it's really 237 00:17:29,209 --> 00:17:32,687 kind of amazing to see how much we don't pay attention. 238 00:17:32,688 --> 00:17:35,964 You know, we usually think that we see with our eyes, but the reality is, we see 239 00:17:35,964 --> 00:17:39,230 with our brains. And our brains fill in the information in 240 00:17:39,230 --> 00:17:43,505 the way that we expect to see it, not necessarily what it is out there, 241 00:17:43,505 --> 00:17:48,111 actually, but what we expect to see. Now why do I start with talking about 242 00:17:48,111 --> 00:17:53,052 decision making irrational behavior, by talking about visual illusions? 243 00:17:53,052 --> 00:17:56,960 I think visual illusions are a great metaphor that help us to think about human 244 00:17:56,960 --> 00:17:58,954 thinking. Think about it. 245 00:17:58,955 --> 00:18:02,040 We have a huge part of our brain dedicated to vision. 246 00:18:02,040 --> 00:18:06,132 We have a huge part here in the back dedicated to vision, does vision all the 247 00:18:06,132 --> 00:18:09,867 time, bigger part of the brain that is dedicated to anything else. 248 00:18:09,868 --> 00:18:13,710 We do vision many hours of the day. We've evolutionary design to do vision. 249 00:18:13,710 --> 00:18:16,910 If you had to pick one thing that people are good at, it's vision. 250 00:18:16,910 --> 00:18:22,676 And nevertheless we have these mistakes. You'll always see the Pisa illusion, 251 00:18:22,676 --> 00:18:27,425 you'll always see the cube illusion. And the question we should ask ourselves, 252 00:18:27,425 --> 00:18:31,780 if with all these benefits, huge mechanism, lot of experience, evolutionary 253 00:18:31,780 --> 00:18:35,867 reasons to do it, with all of those reasons to do vision well, we still have 254 00:18:35,867 --> 00:18:40,624 predictable systematic mistakes in vision, what are the odds that we don't have even 255 00:18:40,624 --> 00:18:44,948 more mistakes in other areas of our lives? What happened to decisions about health 256 00:18:44,948 --> 00:18:46,860 care? Decisions about money? 257 00:18:46,860 --> 00:18:50,292 Those are areas where we don't have a particular brain mechanism, we don't have 258 00:18:50,292 --> 00:18:53,330 that much experience. Evolutionary these are much newer things. 259 00:18:53,330 --> 00:19:00,406 Couldn't it be that in those areas we would have even more predictable and 260 00:19:00,406 --> 00:19:08,877 systematic mistakes that everybody shares? And for the rest of the discussion I want 261 00:19:08,877 --> 00:19:15,395 to present to you the case that this is indeed, this is indeed so.