To find out what makes us human, Brian Hare asks our closest relatives and best friends.
As a new and newsworthy assistant professor of biological anthropology and anatomy at Duke, he’s examining the social abilities of chimpanzees and bonobos, the two endangered species of ape with which we share about 99 percent of our genes.
This summer, the focus is on “xenophobia” (ZEE-no-phobia), the fear of strangers.
Bonobos “are extremely tolerant,” Hare says. “They’re very good at cooperating and much more egalitarian, like we are. Chimpanzees are a lot more hostile. They have a lot of problems. They can even kill each other.”
“What a fantastic opportunity! Here we have hallmarks of being human, and they differ between our two closest relatives.”
With his wife, scientist/journalist/blogger Vanessa Woods, Hare is again going to Africa in mid-June as he has for the last four years to study chimps and bonobos in orphanages.
Bonobos are not pets. These animals were orphaned by poachers.They’ll start at Point-Noire in the Republic of Congo, where three graduate students are already hard at work evaluating the behavior and thought processes of a group of orphaned chimpanzees at the Tchimpounga sanctuary. Then they’ll fly to Brazzaville and boat across the Congo River to Kinshasa in the Democratic Republic of Congo. There they will study a group of orphaned bonobos at the Lola Ya Bonobo Sanctuary.
This summer’s xenophobia testing will involve showing the apes photos of familiar and unfamiliar animals to see which they prefer looking at. “The prediction is that chimpanzees and bonobos will have different preferences,” Hare says. “Bonobos tend to be very peaceful with neighbors they don’t necessarily know very well. Chimpanzees do not.”
Meanwhile, Woods will continue evaluating “social-sexual behavior” among very young bonobos. Earlier research by Hare’s group and others documented that adult bonobos — unlike chimps — use simulated and real sexual activity to ward off tensions among group members. And Woods’ research has also found “2-and 3-year-old babies are already using these social-sexual behaviors.” Hare says. “The question is: does that require a lot of exposure to adults, or does it matter?”
The orphaned chimps and bonobos are the offspring of parents killed for food or trafficked as exotic pets. They’ve formed their own societies of primate peers at the three African wildlife sanctuaries where Hare has negotiated his group’s access to conduct research. At night the orphans can sleep in enclosures comfortably roofed-off from the rain. And by day they can “escape” from the gaze of human monitors within open, natural spaces of up to 100 acres filled with the plants they know.
“I want to see animals living in as rich an environment as possible, because I want to find out how they express their most sophisticated problem-solving abilities,” he says. “These are microcosms of what they would normally experience in the wild, but they’re up to 20 times larger than the world’s largest zoo facility. Not only that, they’re in primary tropical forests.” In such settings, the animals can develop normally despite being orphaned, he adds. “They show very few, if any, of the aberrant behaviors you see in laboratory animals.”
Hare does research with these subjects by their own invitation. “The idea is coming up with experiments that are fun for the animals, so they’ll volunteer to participate,” he says. “In the morning, we ask them if they would like to play games with us. If they’d like to play the games, then we’re doing our jobs well.” Doing such research on animals living in totally wild settings would be impossible as well as unethical, he adds.
Examples of fun and games include the “double rope” exercise in which animals are tested for their ability or inclination to work cooperatively by pulling on opposite ends of a rope connected to a food tray. Only by pulling together can they get a snack. The test highlights striking differences in the attitudes of chimps and bonobos, which split on our family tree about 2 million years ago. All in all, he has been working with apes for 14 years.
Bonobos play with the scientists only if they want to.Ingenious experiments on animal behavior have been Hare’s trademark since his undergraduate days at Emory University’s Yerkes Regional Primate Research Center in Atlanta. He first attracted attention there by taking up his professor’s challenge to prove that his family dogs could infer human thought in the way they followed a pointed finger to the correct Dixie cup where food was hidden.
“I found it interesting that dogs can do this but chimps can’t,” he recalls. “People think solving this pointing problem is also very important for young children as they develop the ability to think about the thoughts of others.”
Ironically, after graduating from Emory (summa cum laude) with anthropology and psychology degrees, Hare failed to be selected as a graduate student at Duke’s well-respected Department of Biological Anthropology and Anatomy. He ended up attending Harvard instead, which he calls “the Duke of the north for me.” At Harvard he expected to continue studying primates but found himself in Siberia evaluating an amazing breeding experiment that had “tamed” silver foxes.
By breeding only the animals that were least aggressive toward humans for 30 successive generations, scientists had turned them into “cute” foxes that behaved much like fawning retrievers. Hare’s experiments showed that they responded to human gestures — such as pointing — just like his dogs did back in Atlanta. Untamed silver foxes did not.
His Harvard advisor on the project – now a research colleague — thinks the same selection pressure is important in the evolution of the bonobos’ friendly behavior toward each other, says Hare.
Arriving at Duke this spring after making a name for himself as director of the Hominoid Psychology Research Group at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, Hare will be doing some chimpanzee research at North Carolina’s state zoo in Asheboro while also rekindling his canine research.
About 800 square feet of space in the Bioscience Building’s basement has been renovated as “a lab for people to bring their pet dogs in to play some fun games,” says Hare, who also has an appointment at Duke’s Center for Cognitive Neuroscience.
“We’ll be able to look at how dogs solve problems.” He explains. In the process, “we can also offer doggy day care.”By Monte Basgall
Monte Basgall is senior science writer at Duke News and Communications.