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The Caretaker

Penny Patterson has dedicated her life to studying Koko the gorilla in the hope of preserving a species


Penny Patterson has dedicated her life to studying Koko the gorilla in the hope of preserving a species.

As part of her research into animal communication in 1972, a young graduate student in developmental psychology volunteered to teach sign language to a 1-year-old female Gorilla named Koko. More than 30 years later, what Francine "Penny" Patterson (AB '70, psychology) initially thought would be a short-term project has blossomed into the longest, continuous experiment into interspecies communication ever. In the process, Koko has become famous, appearing on the cover of National Geographic, on PBS and in the New York Times. Koko has also been visited by celebrities like Mister Rogers.

"When I started this project—this is how naive I was," Patterson says, "I thought I'd do it for four years, and then I'd go find a job."

That "job" has turned out to be Koko, now 32, who lives with Ndume, a male gorilla, at the Gorilla Foundation, a wooded preserve Patterson established in the suburbs of San Francisco after completing a doctorate at Stanford University. With the help of a dedicated team, including fellow LAS graduate Ronald Cohn (BS '65, MS '67 zoology, PhD '71 biology), who documents Koko's life on camera, Patterson has taught the often-playful gorilla to communicate through sign language.

"Working with a gorilla is like working with triplets," Patterson says of the energy required to teach her 5-foot, 300-pound subject, who like humans, is a primate and a member of the great ape family.

Patterson says Koko can sign more than 1,000 words, can understand more than 2,000 words in spoken English, and has an IQ around 90, slightly below the average human intelligence of 100. Koko can start conversations, ask questions, and has even invented new words and her own form of communication, gorilla sign language.

"In fact, Koko creates some new grammatical features [in sign language] that I don't know," Patterson says.

watercolor painting

Penny Patterson believes that apes can converse with humans in sign language and may even be capable of passing on these language skills to their offspring. To the left is a watercolor painting by Koko, a gorilla made famous by Patterson for her apparent skills at signing.

Her findings on Koko have been challenged by linguists such as Noam Chomsky, who maintains that it's impossible for animals to be taught language (Patterson says language is innate among gorillas). Critics have also said Patterson, who has published few scientific papers, is too close with Koko to be objective.

"You can't have language in a vacuum," Patterson says.

The researcher was inspired to become a scientist by her father, C.H. Patterson, a psychologist who taught in the U of I College of Education. When Patterson was a freshman at Illinois, her mother died of cancer, which left the young woman, the oldest of seven siblings, to care for the family. Patterson used the experience as a foundation for her life's work in developmental psychology.

"I was fascinated with development because I watched all of these siblings grow up," Patterson says.

Watching Koko grow up has taught Patterson a lot about the development of all primates. Beyond proving the intelligence of gorillas, whom the researcher calls "quite average" compared to other great apes such as chimpanzees, she says that her work has demonstrated that other species besides humans are capable of complex emotional lives. Koko, Ndume, and Michael, a gorilla who lived with Koko until he died a few years ago, demonstrated a sense of humor, an ability to lie and show remorse and even to recall traumatic experiences. Koko and Michael also painted, and once had an exhibition of their paintings on display.

"They're sentient," Patterson says of gorillas. "They can think and talk about the past and the future."


A famous photograph by Cohn showing Koko cradling a kitten, which appeared on the cover of National Geographic, has helped change the stereotypical image of gorillas presented in the film "King Kong." In reality, Patterson says, gorillas are not aggressive, even when threatened. "They don't attack," she says. "They bluff."

Patterson, who is sometimes mentioned along with Dian Fossey and Jane Goodall, knows how valuable Koko has become as a worldwide symbol for conservation.

"It's an emotional link, a reason why we need to save biodiversity," she says.

Patterson says all species of gorillas could be gone in the next few decades. Not only is their habitat—the forests of Africa—being destroyed, but gorillas, whose "bushmeat" is valued as a delicacy, are also being hunted to extinction by poachers.

The Gorilla Foundation is working to establish an ape preserve in Maui, Hawaii, on 70 acres of land donated by a sugar company.

The Maui Ape Preserve will be much closer to the gorillas' natural environment, and will enable researchers to come together and study the apes in one place. Maui also allows space for other female gorillas, which Patterson says will help Koko feel comfortable enough to mate with Ndume. Patterson says although Koko has expressed a romantic interest in Ndume, Koko's present environment is not close enough to gorilla mating patterns in the wild. "It is always the dominant male and a group of females" who reproduce, Patterson says.

She thinks there is a good chance that Koko will pass on language to her offspring since she has tried to sign to dolls, Patterson says. "She's also tried to teach Michael and Ndume."

So far, Patterson has raised only half of the $6 million she needs for the preserve, which is disappointing to her. She believes that time may be running out for gorillas. "We might lose them all, and that is my greatest fear."

By Scott Spilky
Fall 2003