0:00:01.174,0:00:04.722 My first year in graduate school,[br]studying cooperation in monkeys, 0:00:04.746,0:00:06.969 I spent a lot of time outside, 0:00:06.993,0:00:09.886 just watching our groups[br]of capuchin monkeys interact. 0:00:10.230,0:00:13.827 One afternoon, I was out back[br]feeding peanuts to one of our groups, 0:00:13.851,0:00:16.573 which required distracting[br]one of our males, Ozzie, 0:00:16.597,0:00:19.169 enough so that the other monkeys[br]could get some. 0:00:19.193,0:00:21.328 Ozzie loved peanuts, 0:00:21.352,0:00:24.576 and he always tried to do[br]anything he could to grab some. 0:00:24.941,0:00:26.575 On that day, however, 0:00:26.599,0:00:29.996 he began trying to bring other things[br]from his enclosure to me 0:00:30.020,0:00:32.673 and trade them with me[br]in order to get a peanut. 0:00:33.141,0:00:37.077 Now, capuchins are smart,[br]so this wasn't necessarily a surprise. 0:00:37.101,0:00:38.879 But what was a surprise 0:00:38.903,0:00:41.332 was that some of the things[br]that he was bringing me, 0:00:41.356,0:00:44.371 I was pretty sure he liked[br]better than peanuts. 0:00:44.827,0:00:46.961 First, he brought me[br]a piece of monkey chow, 0:00:46.985,0:00:48.588 which is like dried dog food -- 0:00:48.612,0:00:50.572 it was even made by Purina -- 0:00:50.596,0:00:53.791 and for a monkey,[br]is about as worthless as it gets. 0:00:53.815,0:00:56.260 Of course, I didn't give him[br]a peanut for that. 0:00:56.284,0:00:58.228 But he kept trying, 0:00:58.252,0:01:01.581 and eventually, he brought me[br]a quarter of an orange 0:01:01.605,0:01:04.533 and tried to trade it[br]with me for a peanut. 0:01:05.009,0:01:08.034 Now, oranges are a valuable[br]monkey commodity, 0:01:08.058,0:01:11.264 so this trade seemed, shall I say,[br]a little bit nuts? 0:01:11.621,0:01:14.828 Now you may be wondering[br]how we know what monkeys prefer. 0:01:14.852,0:01:16.177 Well, we ask them, 0:01:16.201,0:01:18.439 by giving them a choice between two foods 0:01:18.463,0:01:20.136 and seeing which one they pick. 0:01:20.160,0:01:23.188 Generally speaking,[br]their preferences are a lot like ours: 0:01:23.212,0:01:25.569 the sweeter it is, the more they like it. 0:01:25.593,0:01:28.347 So, much like humans prefer[br]cupcakes to kale, 0:01:28.371,0:01:31.561 monkeys prefer fruits,[br]like oranges or grapes, 0:01:31.585,0:01:33.236 to vegetables like cucumbers, 0:01:33.260,0:01:35.458 and all of this to monkey chow. 0:01:35.831,0:01:37.514 And peanuts are not bad. 0:01:37.538,0:01:41.219 However, they definitely don't prefer them[br]to a chunk of orange. 0:01:41.243,0:01:44.701 So when Ozzie tried to trade[br]a quarter of an orange for a peanut, 0:01:44.725,0:01:46.058 it was a surprise, 0:01:46.082,0:01:50.066 and I began to wonder[br]if he suddenly wanted that peanut 0:01:50.090,0:01:52.939 because everybody else[br]in his group was getting one. 0:01:53.391,0:01:56.292 In case you're wondering,[br]I did give Ozzie his peanut. 0:01:56.316,0:01:58.983 But then I went straight[br]to my graduate adviser, 0:01:59.007,0:02:00.165 Frans de Waal, 0:02:00.189,0:02:02.149 and we began to design a study 0:02:02.173,0:02:04.292 to see how the monkeys would respond 0:02:04.316,0:02:08.133 when somebody else in their group[br]got a better reward than they did 0:02:08.157,0:02:10.132 for doing the same work. 0:02:10.506,0:02:12.474 It was a very simple study. 0:02:12.498,0:02:14.462 We took two monkeys from the same group 0:02:14.486,0:02:16.331 and had them sit side by side, 0:02:16.355,0:02:17.855 and they would do a task, 0:02:17.879,0:02:19.950 which was trading a token with me, 0:02:19.974,0:02:22.506 and if they did so successfully, 0:02:22.530,0:02:24.045 they got a reward. 0:02:24.069,0:02:27.736 The catch was that one monkey[br]always got a piece of cucumber, 0:02:27.760,0:02:30.625 and the other monkey[br]sometimes got a piece of cucumber, 0:02:30.649,0:02:32.513 but sometimes got a grape. 0:02:32.537,0:02:33.696 And if you'll recall, 0:02:33.720,0:02:36.188 grapes are much preferred to cucumbers 0:02:36.212,0:02:38.426 on the capuchin monkey hierarchy. 0:02:38.450,0:02:40.267 These are two of my capuchin monkeys. 0:02:40.291,0:02:42.934 Winter, on the right,[br]is trading for a grape, 0:02:42.958,0:02:46.021 and Lance, on the left,[br]is trading for a cucumber. 0:02:46.045,0:02:49.426 You can see that she --[br]and yes, Lance is actually a female -- 0:02:49.450,0:02:52.270 is at first perfectly happy[br]with her cucumber, 0:02:52.294,0:02:55.532 until she sees Winter trading for a grape. 0:02:55.946,0:02:59.018 Suddenly, Lance is very[br]enthusiastic about trading. 0:02:59.358,0:03:03.459 She gets her cucumber,[br]takes a bite and then -- 0:03:03.483,0:03:06.285 throws it right back out again. 0:03:06.656,0:03:09.650 Meanwhile, Winter trades again[br]and gets another grape, 0:03:09.674,0:03:13.158 and has Lance's undivided attention[br]while she eats it. 0:03:13.555,0:03:14.728 This time, 0:03:14.752,0:03:17.714 Lance is not[br]so enthusiastic about trading. 0:03:17.738,0:03:20.363 But eventually, she does so. 0:03:20.387,0:03:23.323 But when she gets the cucumber[br]this time around, 0:03:23.347,0:03:26.037 she doesn't even take a bite 0:03:26.061,0:03:28.461 before she throws it back out again. 0:03:28.879,0:03:31.895 Apparently, Lance only wants a cucumber 0:03:31.919,0:03:34.692 when she hasn't just watched[br]Winter eat a grape. 0:03:35.046,0:03:37.117 And Lance was not alone in this. 0:03:37.141,0:03:40.601 All of my capuchins were perfectly happy[br]with their cucumbers 0:03:40.625,0:03:43.442 as long as the other monkeys[br]were getting cucumbers too. 0:03:43.466,0:03:45.974 But they often weren't so happy[br]with their cucumbers 0:03:45.998,0:03:48.561 when other monkeys were getting a grape. 0:03:48.585,0:03:51.401 The obvious question is why? 0:03:51.425,0:03:54.053 If they liked those cucumbers before, 0:03:54.077,0:03:55.244 what changed? 0:03:55.268,0:03:57.101 Now, I'm a scientist, 0:03:57.125,0:04:00.887 and scientists are famously shy[br]about reading too much into our studies, 0:04:00.911,0:04:03.180 especially when it comes[br]to what other animals 0:04:03.204,0:04:04.395 are thinking or feeling, 0:04:04.419,0:04:05.835 because we can't ask them. 0:04:05.859,0:04:08.741 But still, what I was seeing in my monkeys 0:04:08.765,0:04:12.408 looked an awful lot like what we humans[br]would call a sense of fairness. 0:04:12.432,0:04:13.621 After all, 0:04:13.645,0:04:18.125 the difference in that cucumber[br]was that it came after Winter got a grape, 0:04:18.149,0:04:19.669 rather than before. 0:04:20.014,0:04:23.241 We humans are obsessed with fairness. 0:04:23.265,0:04:24.855 I have a younger sister, 0:04:24.879,0:04:26.070 and when we were little, 0:04:26.094,0:04:28.839 if my sister got a bigger piece[br]of the pie than me, 0:04:28.863,0:04:30.506 even by a crumb, 0:04:30.530,0:04:32.236 I was furious. 0:04:32.260,0:04:34.363 It wasn't fair. 0:04:34.387,0:04:37.402 And the childhood me is not alone. 0:04:37.704,0:04:42.132 We humans hate getting[br]less than another so much 0:04:42.156,0:04:43.950 that one study found 0:04:43.974,0:04:46.703 that if humans were given[br]a hypothetical choice 0:04:46.727,0:04:48.894 between earning 50,000 dollars a year 0:04:48.918,0:04:51.155 while others earned 25,000 dollars, 0:04:51.179,0:04:53.441 or earning 100,000 dollars a year 0:04:53.465,0:04:56.227 while others earned 250,000 dollars, 0:04:56.251,0:04:58.323 nearly half the subjects 0:04:58.347,0:05:02.077 prefer to earn 50,000 dollars[br]a year less money 0:05:02.101,0:05:05.644 to avoid earning relatively less[br]than someone else. 0:05:05.668,0:05:07.868 That's a pretty big price to pay. 0:05:08.525,0:05:09.676 What drives people 0:05:09.700,0:05:12.866 to this sort of apparently[br]irrational decision-making? 0:05:12.890,0:05:14.057 After all, 0:05:14.081,0:05:17.176 throwing away your cucumber[br]because someone else got a grape 0:05:17.200,0:05:20.279 only makes sense[br]if it makes things more fair. 0:05:20.756,0:05:24.708 Otherwise, Winter has a grape,[br]and you have nothing. 0:05:24.732,0:05:27.354 Of course humans are not capuchin monkeys. 0:05:27.378,0:05:28.671 But on the surface, 0:05:28.695,0:05:30.553 sacrificing 50,000 dollars 0:05:30.577,0:05:33.315 because somebody else[br]is going to earn more money than you 0:05:33.339,0:05:36.632 makes no more sense[br]than throwing away that cucumber. 0:05:36.656,0:05:38.836 Except maybe it does. 0:05:39.177,0:05:40.804 Some economists think 0:05:40.828,0:05:44.153 that the sense of fairness in humans[br]is tied to cooperation. 0:05:44.645,0:05:47.304 In other words, we need[br]that sense of fairness 0:05:47.328,0:05:49.109 when we're working with somebody else 0:05:49.133,0:05:51.696 to know when we're getting[br]the short end of the stick. 0:05:51.720,0:05:52.879 Think about it this way. 0:05:52.903,0:05:55.871 Let's say you have a colleague at work[br]who's having a hard time 0:05:55.895,0:05:57.347 and needs a little extra help. 0:05:57.371,0:05:59.442 You're probably more[br]than happy to help out, 0:05:59.466,0:06:02.685 especially if she does[br]the same for you when you need it. 0:06:02.709,0:06:05.010 In other words, if things even out. 0:06:05.034,0:06:06.185 But now, 0:06:06.209,0:06:08.756 let's say that colleague[br]is always slacking off 0:06:08.780,0:06:10.363 and dumping extra work on you. 0:06:10.387,0:06:12.664 That's infuriating. 0:06:12.688,0:06:13.839 Or worse, 0:06:13.863,0:06:17.434 what if you're doing all the work,[br]and she's getting paid more. 0:06:17.458,0:06:19.537 You're outraged, right? 0:06:19.895,0:06:22.569 As well you should be. 0:06:22.593,0:06:25.682 That righteous fury[br]is your sense of fairness 0:06:25.706,0:06:29.149 telling you that, well, it's not fair. 0:06:29.173,0:06:32.701 You need to get your fair share[br]from the people you're working with, 0:06:32.725,0:06:35.494 or it's exploitation, not cooperation. 0:06:35.518,0:06:39.550 You may not be able to leave every job[br]where you're treated unfairly, 0:06:39.574,0:06:40.780 but in a perfect world, 0:06:40.804,0:06:42.744 one without racism and sexism 0:06:42.768,0:06:45.768 and the frictions associated[br]with finding a new job, 0:06:45.792,0:06:48.187 it's your sense of fairness[br]that would let you know 0:06:48.211,0:06:50.117 when it was time to move on. 0:06:50.141,0:06:51.514 And if you couldn't? 0:06:51.538,0:06:56.855 Well, that smoldering frustration[br]might make you throw your cucumbers too. 0:06:57.268,0:06:59.339 And humans are not alone in this. 0:06:59.363,0:07:02.752 In the previous study,[br]there was nothing Lance could do about it, 0:07:02.776,0:07:05.012 but what if there had been? 0:07:05.036,0:07:06.226 It turns out 0:07:06.250,0:07:09.616 that capuchins simply refuse[br]to cooperate with other capuchins 0:07:09.640,0:07:12.560 who don't give them their share[br]after they worked together. 0:07:12.584,0:07:15.077 And refusing to work together[br]with another monkey 0:07:15.101,0:07:18.696 is a pretty straightforward way[br]of leveling the playing field. 0:07:19.093,0:07:21.942 Apparently, no monkey[br]getting anything at all 0:07:21.966,0:07:24.387 is better than another[br]monkey getting more. 0:07:24.411,0:07:26.950 But much like you and your coworker, 0:07:26.974,0:07:29.946 they're perfectly happy[br]with a little short-term inequality 0:07:29.970,0:07:33.478 as long as everything evens out[br]over the long run. 0:07:33.502,0:07:36.549 This economic connection[br]between fairness and cooperation 0:07:36.573,0:07:39.415 makes sense to me[br]as an evolutionary biologist. 0:07:39.439,0:07:40.599 After all, 0:07:40.623,0:07:43.260 your ancestors didn't get[br]to pass on their genes 0:07:43.284,0:07:45.998 because they did well[br]in some absolute sense, 0:07:46.022,0:07:48.814 but because they did better than others. 0:07:48.838,0:07:50.776 We don't call it survival of the fit, 0:07:50.800,0:07:52.815 we call it survival of the fittest. 0:07:52.839,0:07:55.291 As in more fit than others. 0:07:55.315,0:07:56.755 It's all relative. 0:07:57.577,0:07:58.728 OK. 0:07:58.752,0:08:01.815 So my capuchins don't like it[br]when they get less than another. 0:08:01.839,0:08:04.506 And they're perfectly happy[br]to sacrifice their cucumbers 0:08:04.530,0:08:05.871 to level the playing field. 0:08:05.895,0:08:07.058 That's great. 0:08:07.082,0:08:10.385 But what we would call[br]a sense of fairness in humans 0:08:10.409,0:08:14.584 also means that we care[br]when we get more than someone else. 0:08:14.933,0:08:16.576 What about my monkeys? 0:08:16.600,0:08:17.901 It turns out 0:08:17.925,0:08:21.714 that primates do notice[br]when they get more than others, 0:08:21.738,0:08:23.920 or at least some of them do. 0:08:23.944,0:08:25.626 My capuchins do not. 0:08:25.960,0:08:28.016 But in one of my studies, 0:08:28.040,0:08:31.482 my chimpanzees would[br]sometimes refuse a grape 0:08:31.506,0:08:35.276 if another chimpanzee[br]in their group got a cucumber, 0:08:35.300,0:08:39.577 which is pretty impressive,[br]given how much my chimpanzees like grapes. 0:08:40.046,0:08:45.078 However, they were still more upset[br]when they got less than another chimp 0:08:45.102,0:08:47.045 as compared to when they got more. 0:08:47.069,0:08:50.172 You may not think it's fair[br]when you have more than your neighbor, 0:08:50.196,0:08:53.807 but you really don't think it's fair[br]when your neighbor has more than you. 0:08:53.831,0:08:55.823 Here's an important question, though. 0:08:55.847,0:08:58.966 Why do we care[br]about inequality or unfairness 0:08:58.990,0:09:01.760 when we are the ones[br]who are unfairly benefiting? 0:09:01.784,0:09:04.413 If evolution is about[br]survival of the fittest, 0:09:04.437,0:09:08.365 wouldn't it make sense to grab[br]any advantage you can get? 0:09:08.810,0:09:10.318 Here's the thing though. 0:09:10.342,0:09:13.056 I do better if I get more than you, sure. 0:09:13.080,0:09:16.155 But best of all is if you and I[br]can work together 0:09:16.179,0:09:19.568 and get more than either one of us[br]could have gotten on our own. 0:09:19.592,0:09:23.354 But why would you work with me[br]if you don't think I'm going to play fair? 0:09:23.378,0:09:26.752 But if you think I'm going to notice[br]when I've got more than you 0:09:26.776,0:09:28.307 and do something about it, 0:09:28.331,0:09:30.275 then you will work with me. 0:09:30.728,0:09:35.379 Evolution has selected us[br]to accept the occasional short-term loss 0:09:35.403,0:09:39.739 in order to maintain these all-important[br]long-term relationships. 0:09:40.125,0:09:42.006 This is true in chimpanzees, 0:09:42.030,0:09:44.847 but it is even more important in humans. 0:09:44.871,0:09:47.991 Humans are incredibly interconnected[br]and interdependent, 0:09:48.369,0:09:50.964 and we have the advanced[br]cognitive abilities 0:09:50.988,0:09:53.877 to be able to plan far into the future. 0:09:53.901,0:09:56.004 And to recognize the importance 0:09:56.028,0:09:58.795 of maintaining these[br]cooperative partnerships. 0:09:59.119,0:10:01.222 Indeed, if anything, 0:10:01.246,0:10:03.453 I think we are likely underplaying 0:10:03.477,0:10:06.282 how important the sense[br]of fairness is for people. 0:10:06.794,0:10:10.523 One of the biggest differences[br]between humans and capuchin monkeys 0:10:10.547,0:10:14.688 is the sheer magnitude and ubiquity[br]of cooperation in humans. 0:10:14.712,0:10:15.871 In other words, 0:10:15.895,0:10:18.966 we're a lot more cooperative[br]than capuchin monkeys are. 0:10:18.990,0:10:22.307 Legal and economic systems[br]literally only exist 0:10:22.331,0:10:24.839 if we all agree to participate in them. 0:10:24.863,0:10:27.514 And if people feel left out[br]of the rewards and benefits 0:10:27.538,0:10:28.688 of those systems, 0:10:28.712,0:10:30.093 then they stop participating, 0:10:30.117,0:10:32.274 and the whole system falls apart. 0:10:32.681,0:10:35.022 Many of the protests[br]and uprisings we're seeing, 0:10:35.046,0:10:37.498 both in the US and around the globe, 0:10:37.522,0:10:39.910 are explicitly framed[br]in terms of fairness, 0:10:39.934,0:10:42.156 which is not surprising to me. 0:10:42.180,0:10:45.758 Whether it's about disproportionate[br]access to resources, 0:10:45.782,0:10:48.789 or that some groups are being[br]disproportionately impacted 0:10:48.813,0:10:51.780 by the legal system[br]or the effects of a virus, 0:10:51.804,0:10:54.625 these protests are the logical outcome 0:10:54.649,0:10:58.624 of our long evolutionary tendency[br]to reject unfairness 0:10:58.648,0:11:02.467 combined with our long history[br]of social stratification. 0:11:02.491,0:11:04.189 And the systemic inequalities 0:11:04.213,0:11:06.705 that have resulted[br]from that stratification. 0:11:06.729,0:11:10.808 Layer on top of this the fact[br]that by many measures 0:11:10.832,0:11:13.673 economic inequality is skyrocketing. 0:11:14.493,0:11:17.556 Chris Boehm wrote a book[br]called "Hierarchy in the Forest," 0:11:17.580,0:11:21.707 in which he argued[br]that humans have reverse hierarchies 0:11:21.731,0:11:24.104 in which those at the bottom band together 0:11:24.128,0:11:27.110 to keep those at the top[br]from taking advantage of them. 0:11:27.531,0:11:31.609 Perhaps these protests[br]are simply the latest manifestation 0:11:31.633,0:11:34.642 of humans' tendency[br]to rebalance the hierarchy. 0:11:34.666,0:11:38.230 Perhaps the biggest difference[br]between us and capuchin monkeys 0:11:38.254,0:11:40.842 is that we can recognize this problem 0:11:40.866,0:11:43.413 and actively work[br]to do something about it. 0:11:43.437,0:11:46.617 Of course we recognize[br]when we're disadvantaged. 0:11:46.641,0:11:50.219 But we can and we must also recognize 0:11:50.243,0:11:53.474 when we're advantaged[br]at the expense of someone else, 0:11:53.498,0:11:55.276 and recognize fairness 0:11:55.300,0:11:58.426 as the balance between[br]these two inequalities, 0:11:58.450,0:12:01.797 because our society[br]literally depends upon it. 0:12:02.391,0:12:04.859 Indeed, my research shows 0:12:04.883,0:12:09.057 that not all primate species[br]care about inequality. 0:12:09.081,0:12:12.299 It's only those that rely on cooperation, 0:12:12.323,0:12:14.910 which most definitely includes humans. 0:12:14.934,0:12:17.037 We evolved to care about fairness 0:12:17.061,0:12:21.103 because we rely on each other[br]for our cooperative society. 0:12:21.127,0:12:23.096 And the more unfair the world gets, 0:12:23.120,0:12:25.008 and the less we care about each other, 0:12:25.032,0:12:26.961 the more peril we will face. 0:12:26.985,0:12:30.135 Our issues are more complex[br]than grapes and cucumbers, 0:12:30.159,0:12:32.595 but as the capuchins have taught us, 0:12:32.619,0:12:35.626 we will all do better[br]when we all play fair. 0:12:35.944,0:12:37.094 Thank you.