June 8, 2010 | 1
NEW YORK—When it comes to brain power, we humans like to think we’re the animal kingdom’s undisputed champions. But in the past few decades we’ve had to make a lot of room on our mantle place for shared trophies. Problem-solving? Sorry, but crows and octopuses do that too. Tool use? Primates, birds and even fish have learned that trick. It turns out our human cognitive abilities are just not as unique as we once thought.
The collapsing divisions between animal and human minds is exactly what a group of scientists gathered to discuss on Saturday, June 5, at a World Science Festival panel, "All Creatures Great and Smart." WNYC radio host Jad Abumrad mediated the talk.
The first topic of conversation was a behavior known as altruism: selflessly helping a stranger. Brian Hare, who studies ape psychology at Duke University, described a recent experiment on this kind of cooperation in bonobos—primates that are in the same genus as chimpanzees.
"We wanted to challenge that notion that humans are unique and test whether one of our closest relatives is capable of voluntarily sharing," Hare said. In the study, published earlier this year in Current Biology, researchers showed a bonobo into a room with some food inside. Instead of hogging all the grub, the bonobo consistently chose to unlock the door of an adjacent room and share the food with an unfamiliar bonobo.
The exact intentions behind this altruistic behavior remain unclear. Bonobos could expect a stranger to return the favor in the future, or "they could just be saying, ‘You know what? I just want to go on a blind date,’" said Hare.
But "the smartest thing about bonobos is that they live in a society with very little violence," said Vanessa Woods, a science communicator and researcher at Duke, who is married to Hare. Woods explained how close-knit groups of females work together to keep the peace in bonobo societies, recounting an incident in which five unrelated female bonobos chased down a male bonobo who slapped another female for no reason. "One male can be stronger than one female, but no male is stronger than five females," Woods said.
"I try to stay good friends with all her girlfriends," Hare said of his wife, in a joking aside.
Altruism, sharing and cooperation aren’t the only sophisticated behaviors animals demonstrate, the panelists explained. Klaus Zuberbühler, who studies the cognitive abilities of non-human primates, has found the rudiments of language in certain monkeys. Vervet and Diana monkeys, for example, have different alarm calls for different predators, reacting in the most appropriate way to signs of a leopard, eagle or snake. What recently astonished researchers is that monkeys aren’t the only ones eavesdropping on each other—birds listen for the distinct calls as well.
Yellow-casqued hornbills—tropical birds that sport dusty orange mohawks—always perk up when Diana monkeys sound the eagle alarm, since eagles are a common enemy. But hornbills don’t react to the Diana’s leopard alarm calls, because leopards usually can’t catch the high-flying birds.
After so much talk about clever monkeys and apes, the panel switched their focus to a group of critters most people don’t associate with intelligence: bugs.
"Insects can accomplish some very sophisticated things without big brains," said Jeremy Niven, an insect neuroscientist at the University of Cambridge. "It kind of makes you wonder why you need an extra billion neurons to be able to do something that a human does."
A slow-motion video of locusts traversing a horizontal ladder made of cocktail sticks played behind the panel. Niven explained how his recent studies show that locusts, despite their tiny brains, use their vision to control their swift leg movements with incredible precision, never missing a rung of the ladder even when the gaps between rungs are inconsistent between trial runs.
For a laugh, Niven also highlighted footage from an experiment designed to shed light on whether bees have aesthetic sensibilities. In the end, all the study showed is that bees prefer Van Gogh’s Sunflowers to more classical flower portraits and to other colorful but flowerless paintings. "It’s not really science," Niven said, chuckling, "but it’s interesting nonetheless."
The panel discussion concluded with a dog show—a mini-parade of canine intelligence.
To set up the show, Hare explained that although many animals can think and make decisions, questions remain about whether animals can interpret the thoughts of others—an ability called "theory of mind" that humans develop by age three or four. One way to test this is to ask whether animals understand the same kinds of social cues human infants learn to recognize—like voice, gesture and gaze.
Sammy, a small white dog reminiscent of Toto from The Wizard of Oz, trotted on stage with his helper. Hare hid a piece of cheese in one of two tall bowls and pointed to the bowl containing the tempting morsel. Sammy immediately followed his direction.
"Are we sure Sammy isn’t smelling the food?" Abumrad asked.
Hare tried the experiment again, but didn’t point at any bowl this time. Sammy tried the wrong bowl and then wandered the stage. "When he doesn’t have a social cue, he goes to the wrong place," Hare said. "We’ve found that dogs are incredibly good at this. They don’t use olfactory cues—they would much prefer that you help them."
It’s especially interesting that dogs are so good at taking social direction because chimpanzees, in contrast, rarely understand the same cues in the same kind of test. The chimps just don’t get it.
In some ways, neither do we. As the panel demonstrated, animal minds are wrapped in many mysterious layers that we’re only beginning to unravel.
Secrets of the Universe: Past, Present, FutureX