A group of baboons spreads out in a wooded area. From the sounds they make, it seems like they’re exchanging “contact barks” with one another. But the purpose isn’t to inform separated individuals of the group’s whereabouts. Individuals simply make the sounds when they are alone or on the periphery, according to Cheney and Seyfarth.

One key difference between humans and non-human primates that is explored in their research is “theory of mind”: Humans have it; monkeys and apes don’t. Identified in the late 1970s by then-Penn psychologists David Premack and Guy Woodruff Gr’77, “theory of mind” is an ability to attribute mental states to others and take them into consideration during one’s communications. Humans aren’t born with this ability but learn it through experience.

To give an example, if you show a three-year-old a box of candy and ask what’s inside, the child will guess “candy.” If you then show the child that the box actually contains matches and ask him what his friend Freddy will say is inside the box, the three-year-old will say “matches.” That’s because before age five or six children don’t recognize the difference between what they and others know.

Monkeys and apes don’t try to inform those who are ignorant or instruct their offspring that something is dangerous for them. Seyfarth and Cheney have found that while baboon vocalizations “often function to alter the behavior of listeners, there is no evidence that callers take into account their audience’s mental state.” Similarly, they write, “listeners’ responses seem governed primarily by learned behavioral contingencies rather than any appreciation of signalers’ motives or beliefs.”

Their interest in the relationship between the natural communication of primates and human language contrasts sharply with well-publicized studies in which chimpanzees or gorillas have been brought to the lab and “taught” a form of human language. Though research in captivity can yield valuable information that is difficult or impossible to obtain in the wild, “you run the risk that your results will give a false picture of the animals’ behavior under natural conditions,” Cheney and Seyfarth write. They prefer to study how primates communicate on their own terms in their natural habitats.

Most researchers who come to the Moremi Game Reserve to study baboons need at least six weeks to tell the individual animals apart from one another. As Cheney describes it, it’s a time of “unrelieved tedium and desperation, boredom, and frustration,” relieved only by the beautiful scenery and the occasional threat of being charged by wild buffaloes. (The key is “to spot them before they spot you,” Seyfarth says, then to move out of the area as quickly as possible.)

Gradually, as one gets to know all the baboons, they become like characters in an “incredible soap opera,” Seyfarth says.

Episode 1: Sierra, who’s much higher ranking, goes over to handle Hannah’s baby. Hannah threatens Sierra, and as a result, Sierra backs off. An hour later Sierra approaches Hannah again. Hannah acts nervous. She’s done something she shouldn’t have. But she lets her guard down when Sierra grunts and smacks her lips in the way that baboons do to show benign intent. Suddenly Sierra jumps on Hannah and bites her.

Jane Austen’s characters don’t go that far, but like most interesting dramas, this one leaves room for interpretation. “On the one hand you could say Sierra has been sitting here fuming for the last hour because she was threatened when she shouldn’t have been,” and she fakes being nice to Hannah to get even, Cheney says. “On the other hand, it could also be that Sierra is like, ‘Oh I want to go be near Hannah, Hannah has a baby. Oh, wait a minute. I seem to remember I’m angry at her.’ Which is less complex.” Perhaps later episodes with a larger cast of characters will offer more clues.

Actual fights among adults are pretty rare in the day-to-day existence of baboons, which is often spent finding food and avoiding predators. But there is plenty of material to keep the researchers occupied. “We can go out for a day of watching with one of our post-docs—and if you were with us, you wouldn’t be hearing any screaming or shouting,” Seyfarth says. “You wouldn’t see any rage of nature, tooth and claw. But on the way back, your post-doc would turn to you and say, ‘Do you detect a seething tension between this family and another?’ And you’d say, ‘Absolutely.’”

 

This summer Seyfarth and Cheney will return to the field to continue their research on the role that hormones and personality may play in the social hierarchy of baboons. Hormones associated with stress may account for certain personality differences; one unglamorous but noninvasive way to find out is collecting and testing baboons’ fecal samples. (The Bingley sisters would be most appalled.)

“There are alpha females and there are alpha females,” Seyfarth says. Some of the top-ranking females are “really insecure—very aggressive, gratuitously nasty.” (Think of Mr. Bingley’s sisters ridiculing Eliza Bennet’s wild hair and muddy petticoat.) “There are other females that are sort of the grand dames, dispensing friendly gestures throughout the group.”

In addition, Cheney says, “there are some low-ranking females everyone seems to like even though they are low ranking.” That would explain the social rise of Jane and Eliza Bennet.

But that’s another story.

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2004 The Pennsylvania Gazette
Last modified 04/27/04

FEATURE:
Who's Who on the Savannah
By Susan Frith
Illustration by Noah Woods

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