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Chimps in Uganda: Lessons from Washoe

This article was published in Scientific American’s former blog network and reflects the views of the author, not necessarily those of Scientific American


October 30th marked the five-year anniversary of the death of my friend Washoe. Washoe was a wonderful friend. She was confident and self-assured. She was a matriarch, a mother figure not only to her adopted son but to others as well. She was kind and caring, but she didn’t suffer fools. Washoe also happened to be known around the world as the first nonhuman to acquire aspects of a human language, American Sign Language. You see, my friend Washoe was a chimpanzee.

Washoe was born somewhere in West Africa around September 1965. Much like the chimpanzees I study here in Uganda, Washoe’s mother cared for her during infancy, nursing her, carrying her, and sharing her sleeping nests with her. That changed when her mother was killed so baby Washoe could be taken from her forest home, then bought by the US Air Force for use in biomedical testing.

Washoe was not used in this sort of testing, however. Instead, Drs. Allen and Beatrix Gardner of the University of Nevada chose her among the young chimpanzees at Holloman Aeromedical Laboratory to be cross-fostered. Cross-fostering occurs when a youngster of one species is reared by adults of a different species.


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In this case, humans raised Washoe exactly as if she were a deaf human child. She learned to brush her teeth, drink from cups, and dress herself, in the same way a human child learns these behaviors. She was also exposed to humans using sign language around her. In fact, humans used only American Sign Language (ASL) to communicate in Washoe’s presence, avoiding spoken English so as to replicate as accurately as possible the learning environment of a young human exposed to sign language.

Washoe began to acquire ASL signs at a young age, and her sign acquisition increased with a pattern bearing many similarities to a young human child’s language acquisition. She used these signs to communicate with humans and, later, with other chimpanzees who also acquired these signs*.

Washoe’s use of ASL signs was groundbreaking. It altered our understanding of what it means to be human. Language was thought to have set us apart from other animals, making us unique among all species. Washoe and her chimpanzee family forced revisions of these old anthropocentric assertions. Later studies showed that all great apes—chimpanzees, bonobos, orangutans, and gorillas—can acquire aspects of human language.

As impressive as Washoe’s role in our understanding of human-ness was, it was not what impressed me most about her. After all, by the time I met Washoe a decade ago, her contributions to debates regarding human uniqueness were well established. Instead, as an intern and later as a master’s degree student at Central Washington University, I was most impressed by the kind of being she was. Here are just a few examples.

She had a strong sense of self. Washoe came to know many human friends at the Chimpanzee and Human Communication Institute (CHCI), her home for over 25 years. Students and interns come from all over the world to study and care for Washoe’s family. As such, Washoe was slow to warm up to strangers. Though she would often ask to see a new person’s shoes (she had an affinity for footwear and would always notice if caregivers had a new pair of shoes), it sometimes took months or more before she trusted people enough to share more in-depth interactions.

The training process for chimpanzee caregivers takes several months as the chimpanzees come to know you and you learn how to safely interact through the fencing that separates them from you. For the safety of both, caregivers never penetrate the fencing or enter into the chimpanzees’ enclosures while they are inside. As a trainer for new caregivers, I witnessed Washoe’s relationships develop with numerous friends. In general, she and the other chimpanzees can read people like nobody’s business. She could size up a new person in an instant. Perhaps most importantly, she sensed whether or not you knew she was boss. She was the alpha (most dominant) chimpanzee in her chimpanzee and human family, and she expected to be treated that way. Washoe could easily spot a new person who appeared arrogant or who “talked down” to her. It wasn’t a good way to earn her friendship easily, and subsequently, newbies usually learned quickly about the rules of chimpanzee society.

It was always best to greet Washoe first, to serve her dinner first, and to leave a little extra so she could be sure to have a bit more if she wanted it. These acts were not indications of favoritism. They were simply ways of taking the chimpanzees on their terms, of recognizing that Washoe was alpha and that alpha status in chimpanzee society affords certain advantages. The other members of her chimpanzee family also understood and expected this.

She drove a hard bargain. Once, after some maintenance men completed repairs, I discovered that they had inadvertently left a wrench very high on a ledge of one of the chimpanzees’ enclosures. Unfortunately, I found this out when I greeted Washoe and saw that she was busily testing the bolts along the enclosure’s fencing with the wrench. Luckily, she really wasn’t getting far with it, but I certainly didn’t want to explore the limits of her mechanical skills. I needed to get the wrench back, but how? I decided to try for a trade.

Though the chimpanzees have a far healthier diet than me most of the time, they enjoy treats every once in a great while. Coffee is a favored treat beverage, so I poured some coffee with creamer and excitedly presented it to Washoe and Tatu, who also happened to be nearby. I signed to ask for the wrench back. Tatu seemed eager to take me up on the offer, but Washoe looked unimpressed as she continued to clutch the wrench. It was time to up the ante. Washoe loved soda, so I poured some of that instead. This piqued her interest, so I asked for the wrench again. She gladly handed it over and enjoyed the soda along with Tatu. Washoe knew that the first rule of negotiating is never to accept a first offer. It paid off.

She was brainy and creative. When caregivers at CHCI clean the chimpanzees’ enclosures, they use hot water from hoses to spray down and rinse areas. While caregivers clean an area the chimpanzees are no longer using, the chimpanzees sometimes come to the fence of an adjacent room and ask for drinks from the hose. Washoe often liked to sip her hot water from a cup as she watched us clean. Sometimes she also made herself a day nest and reclined luxuriously as warm steam poured into her enclosure through the fence, creating her own personal sauna area.

On this particular day, she looked around, but no cups were nearby. Instead, she picked up the hollow rubber head of a baby doll. (Though Washoe liked children, baby dolls didn’t often fare well in her care.) She inverted the doll head and held it up to the fence so I could aim the stream of hot hose water into the head. Though I probably never would have considered the functionality of this object as a container, Washoe quickly solved the problem and found herself a perfectly good cup.

Though Washoe was a very unique individual, she was in other respects an ordinary chimpanzee. That is, she was not a brilliant exception among chimpanzees. The other members of her chimpanzee family also acquired ASL signs. Though her upbringing was distinct, she shares a great deal with the chimpanzees I study here in Uganda. Chimpanzees here share similar sentience, a similar reliance upon gestural communication (while using a somewhat different set of gestures), and a similar capacity for joy and pain.

Thus, while Washoe is a great ambassador for chimpanzees, she should not be placed on a pedestal as uniquely gifted among her kind. She is just one chimpanzee of many taken from her African forest home and transferred to an utterly foreign place to lead an altogether different life than the one she would have otherwise had. Thankfully, it’s no longer legal to capture chimpanzees from Africa and transport them abroad. It still happens occasionally, but realistically, threats like bushmeat hunting and habitat loss pose much greater risks to free-living chimpanzees today. Though I miss Washoe now and always, I’ll always be grateful for the many lessons she taught me about herself and her kin which, after all, includes us humans too.

*The members of Washoe’s chimpanzee family at the Chimpanzee and Human Communication Institute are equally spectacular beings, with their own fascinating life histories. This “family” is not biologically related, but has been a stable family unit for over 30 years. Read more about the others—Moja, Tatu, Dar, and Loulis—at www.friendsofwashoe.org.

Learn more about Washoe and her family:

The book I highly recommend: Next of Kin, by Roger Fouts with Stephen Tukel Mills

The website with lots more info: Friends of Washoe

The research publications

Previously in this series:

Chimps in Uganda: Two weeks and counting….

Chimps in Uganda: “These are a few of my favorite things”

Chimps in Uganda: Home Sweet Home

Chimps in Uganda: Bustling Kampala and Unwanted Houseguests

Chimps in Uganda: Reading the Clues

Maureen McCarthy is a PhD Candidate in Integrative and Evolutionary Biology at the University of Southern California. She received her Master's Degree in Experimental Psychology from Central Washington University, where she studied the gestural communication of chimpanzees who have acquired American Sign Language. She has more than a decade of experience studying captive and free-ranging primates. Maureen is currently in Uganda for a year to study the behavioral ecology and genetics of chimpanzees in fragmented forest habitats. Dr. Craig Stanford advises her research. This is Maureen's fourth trip to Uganda--she's been there several times before to volunteer as a research assistant and to collect pilot data for her dissertation. When she's not busy collecting chimpanzee poop or getting malaria, Maureen enjoys birding, hiking, and photography. This research would not be possible without the generous support of the USC Dornsife College of Letters, Arts, and Sciences, the USC Jane Goodall Center, Primate Conservation, Inc., and the American Society of Primatologists.

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