# Two monkeys were paid unequally

Cucumber or grapes? What happens when two monkeys do the same task but get 'paid' in different ways? Watch this funny video to find out how monkeys react to inequality.

### Instructions

Do the preparation task first. Then watch the video and do the exercises. You can also read the transcript.

### Transcript

So, the 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 ten 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 two 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 two 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, it'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'd 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(s) that the first piece of cucumber is perfectly fine. The first piece she eats. 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.

(audience laugh)

She tests a rock now against the wall. She needs to give it to us. And she gets cucumber again.

(audience laugh)

So this is basically the Wall Street protest that you see here.

### Topics

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Submitted by Miguelitorico1996 on Fri, 04/02/2022 - 03:00

He compares monkeys to humans because we both came from the same origin as far as evolution is concerned, and you can also notice that this sense of unfairness is in other species as he mentioned that that experiment has been tried on dogs, birds and others animals.

Submitted by Rafaela1 on Sun, 13/06/2021 - 13:56

I don’t like a chimp. ;|

Submitted by nikoslado on Sun, 03/05/2020 - 20:57

Dear Team, I think in Task 1, seventh line, according to in the video reactions of the first monkey, the answer should be the''True''one. I mean, firstly we see this monkey giving back the rock easy, without any other reaction.I think that her testing the rock against the wall it occurs the fact that the other fellow takes grapes instead of cucumbers,so ''she is so angry'' as the test says. Otherwise this reaction of her doesn't make any sense.

Submitted by Kirk Moore on Mon, 04/05/2020 - 07:04

When we wrote that question, we were following what the researcher says, which is 'She tests a rock now against the wall', which suggests that the purpose of this action was to confirm that the rock was indeed a rock (and not some trick). I think it's fair to say that she is angry, but 'so angry' seems a little too extreme, which is why we marked that question as False.

All the best

Kirk

The LearnEnglish Team

Submitted by Rafaela1 on Wed, 06/11/2019 - 09:38

Compared with human beings, this experiment may suggest that there's a difference between a kid raised as an only a child and that with siblings who are close in age. Well... a hierachy may have a good reason in a society of human beings (monkeys)!?

Submitted by fidaasiddig on Tue, 05/11/2019 - 12:06

Hello Would you explain this(the food preferences of my capuchin monkeys correspond exactly with the prices in the supermarket) I didn't get the whole idea

Submitted by Kirk Moore on Wed, 06/11/2019 - 07:53

Hello fidaasiddig

It means that the monkeys' preference for grapes over cucumber is similar to the difference in prices in the supermarket -- that is, grapers are more expensive (more preferred) than cucumber. This is not an important observation in this video.

All the best

Kirk

The LearnEnglish Team

Submitted by yuriwm on Mon, 24/06/2019 - 16:23