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  • From: Natasha Matza <nmmatza AT mac.com>
  • To: monkeywire AT lists.ibiblio.org
  • Subject: [monkeywire] Dumb Gorillas Need Not Apply
  • Date: Fri, 17 Oct 2008 22:47:49 -0500

http://www.chicagotribune.com/features/chi-smart-gorillas-15- oct15,0,703825.story

Dumb gorillas need not apply
Rollie, other apes at Lincoln Park Zoo show smarts in tests

By William Mullen | Chicago Tribune reporter
October 15, 2008

Smarter than she looks
<photo>
Rollie, a female gorilla at Lincoln Park Zoo, is disproving the conventional wisdom that gorillas are somewhat less intelligent than their great ape cousins. (Tribune photo by Chris Walker / October 15, 2008)

When the frozen blueberry rolled out of a tube near a 42-inch touch-screen computer in the Lincoln Park Zoo's great ape house, a lowland gorilla named Rollie popped the berry into her mouth, gleefully stomped her feet and let out a celebratory hoot.

Rollie had correctly solved a seven-step number puzzle on the screen, winning a treat and an enthusiastic cheer from a keeper. But her skills are also being noticed outside the confines of the zoo.

Conventional wisdom has it that gorillas are somewhat less intelligent than their great ape cousins. Rollie's surprising success at her morning research routine is challenging those assumptions, suggesting she might in fact be faster on the uptake than chimpanzees and orangutans. A report on her work recently caused a stir at the biennial meeting of the International Primatological Society Congress in Scotland.

"Gorillas have always had a reputation of being a little bit slower-witted than other great apes," said Steve Ross, who supervises cognitive and behavioral research for the zoo's primate research arm, the Lester E. Fisher Center for the Study and Conservation of Apes. "They aren't as dynamic as chimps socially, and they don't show the mechanical cleverness that orangutans display."

Ross admits he subscribed to the theory himself.

"This study can't generalize for all gorillas, but because [Rollie] has been such a quick learner, it suggests that gorillas in general are smarter than we have given them credit for," he said.

Ross' immediate aim in studying primate cognition and intelligence is to devise preference tests that allow animals to "talk" to keepers, expressing what foods they like and don't like and reporting on good and bad features of their habitats. But exploring animal cognition also is a way of looking at the history of human intellect and language, giving insights into how they evolved.

Chimpanzees and orangutans are studied often at primate and medical research laboratories worldwide. But captive gorillas—perhaps too temperamental as adults to be used as research subjects—aren't often kept outside of zoos, so they are far less studied.

Lincoln Park, in fact, is the only place in the world that is doing touch-screen testing with both chimps and gorillas.

"It is exciting to see that [Rollie's] performance is comparable with other great apes," said Tara Stoinski, a Zoo Atlanta primatologist. "What is really exciting is to see this kind of work being done with gorillas because so little research is being done on gorilla cognition."

Ross first started training some chimpanzees in 2005 to do tasks on a touch-screen computer. He waited some months before training Rollie as his first gorilla subject.

At first, she merely had to touch the blank computer screen to get a reward. Later, she would be rewarded only after touching a floating numeral 1 about 2 inches high. When the number 2 was added, she was not rewarded unless she touched the numbers in the right sequence. Rollie can now touch the numbers 1 to 7 in order.

Ross emphasizes that Rollie, age 12, is not counting.

"This . . . is mastering the task of sequencing—categorizing—which is an important cognitive skill that humans depend on," he said. "We memorize sequences so that we can remember phone numbers, understand a calendar or perform dance steps. The most important use of the skill is language in which we learn the rules of syntax, what parts of speech come first, second and third."

The exercise Rollie works on is similar to one used elsewhere to test other animal species that display high intelligence, including pigeons, rhesus and capuchin monkeys, lemurs and chimps.

Still, "there are some big differences in the research regimes," Ross said. "A rhesus monkey in a lab setting might have 1,000 trials at a time, while we have very limited time with our apes, doing 30 trials at a time."

The animals' motivation to perform varies too.

"The testing period with the snack rewards may be the highlight of the day for lab animals," Ross said. "In the zoo . . . our animals live with families, friends and intergenerational companionship, [so] there isn't as much motivation to learn a skill on a computer for token rewards. That makes Rollie's performance all the more impressive."

Thus far, she has outperformed Optimus, a 9-year-old male chimp being measured in an identical test regimen.

Ross has begun broadening his gorilla data by recruiting two other apes for the computer exercises: Kwan, a regal 19-year-old male silverback, and Azizi, an impish 4-year-old male who is showing signs of being an even faster learner than Rollie.

There are differences in style when gorillas and chimpanzees work the computer, Ross said. Chimps, like humans, let their hand hover, index finger extended, in front of the screen before touching the icon they want. Gorillas use knuckles instead of fingers to touch, and their hands sweep recklessly across the screen before striking the target. Sometimes they accidentally swipe a wrong number on the way, aborting the test.

As a reward, chimps like sugarless, jelly bean-like Primatreats in banana and piña colada flavors. But the first time Kwan smelled a Primatreat, the gorilla threw it out of his cage. Gorillas prefer frozen blueberries or dried pasta.

And some animals, including Rollie, don't much care if they are rewarded or not.

"Rollie is a really motivated gorilla," Ross said. "All of the animals participate willingly in the experiment, but Rollie seems to enjoy the computer tasks so much, she will even do it without getting a food reward, but just for the joy it gives her."

wmullen AT tribune.com






  • [monkeywire] Dumb Gorillas Need Not Apply, Natasha Matza, 10/17/2008

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