Chimps Indifferent to Others' Welfare
RENEE MONTAGNE, host:
Humans give blood. Humans donate money to hurricane victims. They do nice things for each other just because. But what about our relatives the chimps? Research being published in the journal Nature suggests that, in some situations anyway, chimps don't care about helping other chimps, even when helping out doesn't take any extra work. NPR's David Kestenbaum reports.
DAVID KESTENBAUM reporting:
Yes, there are wars, there is torture in the world, but that's not the whole story. Joan Silk is a primatologist at the University of California, Los Angeles.
Ms. JOAN SILK (University of California, Los Angeles): If somebody is getting on the bus struggling with, you know, a stroller and three packages of groceries and a small child, you help them onto the bus probably.
KESTENBAUM: Even though you're not expecting to get anything in return. So why is this? Is it just because we have big brains and have a sense of ourselves and a sense of others? Does intelligence somehow make us concerned for others? It's a good question.
Ms. SILK: So I just wanted to know whether or not this kind of thing happens in chimpanzees.
KESTENBAUM: Chimps are also intelligent and self-aware. It seemed like a good test. Here's the experiment. Her team presented a chimp with two ropes. If the chimp pulled the first rope, he or she got a small bit of food--say, a piece of banana. If the chimp pulled the second rope, the reward was the same, a small piece of food and also an identical small piece of food was dispensed in the enclosure next door for a second chimp. Stick a human in this situation, she says, and they'd probably pull the second rope. Why not help someone else out if it doesn't take any extra work?
Ms. SILK: My 11-year-old daughter swears that's the one she would pick.
KESTENBAUM: But the chimps didn't seem to care.
Ms. SILK: The chimps were entirely indifferent.
KESTENBAUM: They pulled rope one about half the time and rope two about half the time, even though sometimes the other chimp through the window was making begging gestures, indicating `Give me food.'
Ms. SILK: They had their face right up there sometimes, but the begging gestures don't seem to have had a big impact on the other chimps' behavior.
KESTENBAUM: The chimps weren't actively mean. They didn't always select the option that denied the other chimp food. Helping just didn't seem to cross their minds, which leaves Joan Silk puzzling about why people would pull the second rope. Maybe, she says, it's because we live in societies built on cooperation.
Ms. SILK: I think it's important to realize just how cooperative people are and how different they are from other creatures. The scale of cooperation is different. What we have accomplished as humans is based on an ability to cooperate. We've got markets, we've got stratified societies, we've got division of labor, and other animals haven't managed this. And the question is why? What is it that has allowed us to do it and other animals not? You know, I think that's a fantastic question.
KESTENBAUM: But Franz de Waal at Emory University cautions against reading too much into this new experiment. He says chimps do help each other out sometimes. They share food, comfort each other.
Mr. FRANZ DE WAAL (Emory University): We have an old female who's arthritic who can barely climb anymore, and we've seen unrelated younger females push her up by her butt, so to speak, to push her up into the climber so that she can get on top of it.
KESTENBAUM: De Waal says maybe the chimps in the new experiment were overwhelmed by an impulse stronger than empathy, the burning desire to eat a piece of banana.
Mr. DE WAAL: So they may realize that they could help the other, but they're so focused on the food that they never get to that point.
KESTENBAUM: De Waal just wrote a book called "Our Inner Ape." He says people sometimes act like the chimps in this experiment. If there's a sale at a department store, you can get a stampede of customers more concerned with a pair of half-priced shoes than the needs of others. David Kestenbaum, NPR News.
MONTAGNE: This is NPR News.