Frans de Waal describes a landmark experiment with capuchin monkeys that reveals fairness is hardwired into our biology. Two monkeys exchange rocks for food, but when one gets grapes and the other gets cucumber, the cucumber monkey refuses the reward and throws the rock in protest. The same inequity aversion appears in dogs, birds, and chimpanzees.
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These are the pillars of morality. If you ask anyone what is morality based on, these are the 2 factors that always come out. One is reciprocity, and associated with it is a sense of justice and a sense of fairness. And the other one is empathy and compassion. And human morality is more than this, but if you would remove these 2 pillars, there would be not much remaining, I think. And so they're absolutely essential. So let me— So final experiment that I want to mention to you is our fairness study. And so this became a very famous study, and there's now many more, because after we did this about 10 years ago, it became very well known. And we did that originally with capuchin monkeys, and I'm going to show you the first experiment that we did. It has now been done with dogs, and with birds, and with chimpanzees, but with Sarah Brosnan, we started out with capuchin monkeys. So what we did is we put 2 capuchin monkeys side by side. Again, these animals, they live in a group, they know each other. We take them out of the group, put them in a test chamber, And there's a very simple task that they need to do. And if you give both of them cucumber for the task, the 2 monkeys side by side, they're perfectly willing to do this 25 times in a row. So cucumber, even though it's really only water in my opinion, but cucumber is perfectly fine for them. Now if you give the partner grapes, the food preferences of my Capuchin monkeys correspond exactly with the prices in the supermarket. And so, if you give them grapes, that's a far better food, then you create inequity between them. So that's the experiment we did. Recently, we videotaped it with new monkeys who had never done the task, thinking that maybe they would have a stronger reaction, and that turned out to be right. The one on the left is the monkey who gets cucumber. The one on the right is the one who gets grapes. The one who gets cucumber, note that the first piece of cucumber is perfectly fine. The first piece he eats. And then she sees the other one getting grape, and you will see what happens. So she gives a rock to us, that's the task, and we give her a piece of cucumber and she eats it. The other one needs to give a rock to us, and that's what she does, and she gets a grape, and she eats it. The other one sees that, she gives a rock to us now, gets again cucumber. Grape. Cucumber. She tests the rock now against the wall. She needs to give it to us. And she gets cucumber again. So this is basically the Wall Street protest that you see here.
