on bonobos, capuchins, and chimps

the other primates always make me smile. (^_^) here are a couple of quotes from a nice interview of frans de waal over @the primate diaries:

“Johnson: How does the environment affect this? For example, you’ve written that there are distinct differences between bonobos and chimpanzees despite the fact that they are so close genetically. Bonobos live in a female dominated society even though the males are still somewhat larger. You have suggested, as has the bonobo field researcher Frances White (who was one of my advisers in graduate school) that the environment may hold the answer to why this is.

“De Waal: It is possible that bonobos live in a richer environment and have more food sources in their forest that are less dispersed than chimpanzees do. They also have access to ground vegetation, which chimpanzees have to compete with gorillas over. As a result, bonobo females can travel together and don’t need to disperse like chimpanzee females do. Chimp females largely forage alone and would only be competing with each other if they foraged in a large group since the food patches are small. Because bonobo females can travel together, this gives them power in the sense that they can form coalitions against males. They’re very cooperative with each other and that’s how they keep the males in check. The males individually are dominant, but as soon as you get two or three females together they dominate the male.

“Johnson: Chimpanzees have long been the model for human evolution and have been used to justify the story that Huxley advocated about our violent past. Chimps have been known to form all-male bands that patrol their territory, even attacking and killing males from rival groups. However, bonobos show very different behaviors and have even been observed grooming males from other groups. Would you say that these behaviors are purely genetic or, as Cristophe Boesch and Gottfried Hohmann have suggested, that the environment is key to understanding why chimpanzees and bonobos behave so differently? Could it be a behavioral flexibility that is learned or even cultural in origin?

“De Waal: It is true that most chimpanzees and bonobos are very flexible animals who under different circumstances behave differently. We’re in the process of documenting that in Africa and you can also see the same thing in zoo groups. But if you look at, say, a group of twenty chimpanzees or twenty bonobos on a large island, and we have that kind of situation today, the bonobos behave very differently than the chimpanzees. Many of these differences are not just environmentally induced because the zoo environments are pretty much identical….

“Johnson: Today we are faced with what has widely been termed a ‘culture of corruption.’ In your latest book you point to the abuses on Wall Street in which financiers have willfully defrauded the public and Washington politicians who operate through a revolving door of political favors and corporate kickbacks. Is there something in this research with our evolutionary relatives that can help us change our political culture? For example, you and your colleague Sarah Brosnan discovered something very interesting in your study with chimpanzees and capuchin monkeys concerning economic behavior.

“De Waal: Yes, the first experiment was with capuchin monkeys where we would put two monkeys side by side and we would give them rewards for a very simple task. If you give them the same reward, such as small pieces of cucumber, they’re perfectly happy to do this many times in a row. But if you give one of the two monkeys a grape and the second a cucumber then the second monkey gets mad and refuses to perform the task. We have repeated this with chimpanzees where Sarah found that the one who gets more is also affected and refuses the task unless the other one also gets a grape. With this we’re getting very close to the sense of fairness.

interesting! but, me being me (with my quirky interest) would want to know, of course, if the chimps were related to one another or not.

read the whole interview over @the primate diaries.

see also: Why do people and other primates share food?

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