Great ape language

Facial expressions can be used to convey a message.

Great ape language research historically involved attempts to teach chimpanzees, bonobos, gorillas and orangutans to communicate using imitative human speech, sign language, physical tokens and computerized lexigrams. These studies were controversial, with debate focused on the definition of language, the welfare of test subjects, and the anthropocentric nature of this line of inquiry.

The consensus among linguists remains that language is unique to humans.

Contemporary research has steered away from attempting to teach apes human language and focuses instead on observing apes' intraspecies communication in zoos and natural habitats. This includes gestures, facial expressions, and vocalizations.

1890s: Richard L. Garner

Richard L. Garner lived in a cage to study gorillas in the field. Illustration from Apes and Monkeys: Their Life and Language (1900)

Richard Lynch Garner was the first researcher to explore in depth the communication skills of nonhuman primates. He began in 1884 studying monkeys in American zoos and later travelled to Africa to study gorillas and chimpanzees. He wrote frequently for popular journals and newspapers and ultimately had three books published on the subject, The Speech of Monkeys (1892), Gorillas & Chimpanzees (1896), and Apes and Monkeys: Their Life and Language (1900).

Garner argued that nonhuman primates have their own forms of speech. He claimed to be able to talk to the animals and act as their interpreter. His methods and conclusions were not scientific by any modern definition, but his work was nonetheless significant. For one thing, Garner studied the animals' intraspecies vocalizations, in some cases in their natural habitats. He went to great length to do so, even living inside of a cage himself to observe gorillas in Africa. This was in contrast to later language studies, which separated apes from their conspecifics (peers) and placed them in alien — human — habitats. Second, Garner pioneered the use of recording primate vocalizations and playing them back later for experimental purposes.

1920s: Cross-fostering and efforts to teach speaking

The next line of research came out of cross-fostering studies, where chimpanzees were raised in homes as if they were human children. In the 1920s, Luella and Winthrop Niles Kellogg, scientists at Indiana University, raised an infant chimpanzee named Gua alongside their human child, Donald. In The Ape and the Child, the Kelloggs wrote that "it was very clear during the first few months that the ape was considerably superior to the child in responding to human words. She began to react distinctively to separate vocal stimuli within a few weeks after she had entered the human environment."

The Kelloggs noted that Gua made several distinct vocalizations to communicate different needs, and, accordingly, tried to teach her to speak English words. The Kelloggs were building on primatologist Robert Yerkes' assertion:

It seemingly is well established that the motor mechanism of voice in this ape is adequate not only to the production of a considerable variety of sounds, but also to definite articulations similar to those of man.

But Gua did not communicate using human words. Instead of the chimp copying the humans, the Kelloggs' son Donald started copying the chimp, adopting Gua's vocalizations. Donald would use food grunts, for example, when hungry. Shortly after the Kelloggs made this observation, the experiment was discontinued.

After the Kellogg study, there were four similar research projects into cross-fostering. The most notable of these was conducted by Keith and Catherine Hayes with their chimpanzee Viki. Viki would lead people to places she wanted to go as well as move the hands of people onto objects she wanted them to manipulate. She would rarely point to objects that she wanted; instead she would make gestures. For example, when she wanted to help with ironing, she would move her hand back and forth above the ironing board. This experiment with Viki would inspire other researchers to conduct similar experiments. But when it came to teaching Viki to speak, the Hayes' efforts were only marginally more effective than others who tried to teach chimps to talk. After nearly seven years of intensive exposure to English, Viki spoke only four words, mama, papa, cup, and up.

1960s–1980s: Sign language

Washoe and the Gardners

Main article: Washoe (chimpanzee)

R. Allen Gardner and Washoe signing "more". From Archives of the History of American Psychology, The University of Akron.

In 1966, the husband-and-wife research team of Beatrix T. Gardner and Robert Allen Gardner initiated a new generation of language research. After the failed efforts of teaching apes to speak, the Garners wondered whether the issue was a motor deficiency rather than cognitive inability. The couple had been watching film of Viki, the chimp involved in the early speech study, and noticed that she was intelligible without sound; she was making gestures with her hands as she tried to pronounce words. The Gardners decided to test a chimpanzee's abilities with a gestural language, American Sign Language (ASL). They were not the first scientists to come up with this idea. Pepys advocated teaching sign language to chimps in the 17th century; Lan Mettrie and Monboddo suggested the same in the 18th; and William Wundt in the early 20th century. But the Gardners were the first to conduct formal research into the matter.

The Garners secured a 10-month-old chimpanzee they named Washoe in June 1966. Up the age 5, Washoe lived in a trailer in the backyard of the Gardner's home in Reno, Nevada. The Gardner's hired graduate students to work with Washoe, most notably Roger Fouts, who later became Washoe's primary caregiver. No one around Washoe was allowed to speak; instead, they were instructed to use signs from American Sign Language (ASL) exclusively. Washoe's primary caregivers were not fluent in ASL. The Gardners' employed native ASL speakers on subsequent chimp projects.

The Gardners tried to anticipate criticism of their work from the start. A word would not be counted as part of Washoe's vocabulary until she had used it appropriately and spontaneously at least once a day for 15 consecutive days. (Penny Patterson used this framework for her studies with gorilla Koko as well, at least initially.) It proved to be a difficult benchmark to meet, especially when it came to the vocabulary involving things not typically encountered daily (horse, pipe, hankie).

In addition, the Gardners set up a double-blind testing apparatus for Washoe and subsequent chimp language projects. The chimp was seated in front of a screen that was sheltered from human view. One person would flash random slides for the ape to see, another person (who could not see the slides) would record the ape's response, and a third person viewing from a one-way mirror in a separate room would independently record the chimp's response. Two persons were employed to separately interpret Washoe because of the inherent ambiguity of reading an ape's signs: chimp hands and body are different than humans', and the meaning of ASL signs is shaped by their position and movement in space regarding one's body. When the two interpretations were found to match each other as well as the picture that had been shown, the sign was accepted as correct. Anything else was recorded as an error. (In his book, Next of Kin, Roger Fouts wrote that he sometimes found the errors more illuminating than correct responses.)

The double-blind testing apparatus was set up to avoid unconscious bias, particularly a Clever Hans effect, in which humans unwittingly tip off their animal subjects through body language, facial expressions, or other means.

Tests showed Washoe reliably used 85 signs singly and in combination with other words by her third year with the Gardners. (The number of reliable signs rose to 132 later.). According to Eugene Linden, an independent journalist who focused on ape language research, she asked questions and used negatives ("no" in combination with another word).

When Washoe was five, the Gardners arranged to send her to the University of Oklahoma's Institute of Primate Studies in Norman, Oklahoma, with Roger Fouts and Deborah Fouts. The Gardners continued to conduct sign-language research on infant chimpanzees, using Moja, Pili, Tatu, and Dar in subsequent studies. With these later projects, they couple sought to improve on the methodology of Project Washoe by securing chimps immediately after birth, employing fluent ASL speakers, providing the chimps with chimp "siblings"; and iterating upon their language training techniques.

Washoe and Roger Fouts

Main article: Roger Fouts

The Gardners were scientists schooled in behaviorism. Roger Fouts came to the chimp language studies as an animal lover pursuing a career in Child Development. These differing backgrounds corresponded with differing approaches. The Gardners initially wanted Fouts and other grad students to strictly use methods of operant conditioning — rewards and punishment — to teach Washoe, but Fouts believed that teaching a language was not the same as teaching a lab rat tricks. He recalled:

According to behaviorism, the combination of a hungry chimp and ready-to-dispense food should be the perfect opportunity for reinforcement and learning. But the hungrier Washoe was, the quicker her signing deteriorated into pure repetition and finally outright begging.

Fouts believed that chimpanzees needed room to learn in manner similar to human children, on their own timeline. He considered direct instruction ineffective, as it was often met with resistance. The child, not the parent, drives the learning process, argued Fouts:

If you try to impose a rigid discipline while teaching a child or a chimp, you are working against the boundless curiosity and need for relaxed play that make learning possible.

Though the Gardners instituted Skinnerian protocols in Washoe's first year, they began to see advantages to Fouts' approach, acknowledging, "Young chimpanzees and young children have a limited tolerance for school." But the issue exposed a key tension behind Project Washoe and similar language research to follow. On one hand, researchers needed a strict, repetitive process with clinical double-blind testing for their work to be accepted as science. Without such rigor, the body of work became vulnerable to criticism. On the other hand, researchers need to recognize the apes' emotional needs or they faced a different suite of problems. The Gardners fit more comfortably in the first camp, focused on scientific rigor; Roger Fouts and his wife Deborah fit more in the latter, later becoming advocates for animal rights and welfare. But the tension proved unavoidable.

Nim Chimpsky

Main article: Nim Chimpsky

In 1973, Herbert S. Terrace of Columbia University set out to improve upon the Washoe research using a chimp he named Nim Chimpsky (a pun on linguist Noam Chomsky). Over the course of Project Nim, the infant chimp was shuttled between locations and a revolving group of roughly 60 caregivers, mostly students and volunteers, few of whom were proficient in sign language.

Before he was 1 year old, Nim began fighting for dominance by biting his caregivers. The project was initially intended to last roughly 10 years. But after four years of research, Nim had become too difficult to manage and was returned to the Institute for Primate Studies in Oklahoma.

Nim's chaotic upbringing, documented in Elizabeth Hess's biography Nim Chimpsky: The Chimp Who Would Be Human, negatively impacted not only his behavior but his performance on language-related tasks. Even Terrace acknowledged this problem, noting that Nim's "emotional turmoil" was a "major obstacle" in his progress.

After sending Nim back to Oklahoma, Terrace reviewed his data and concluded that Nim copied signs from his teachers to get a reward. Terrace argued that Nim did not initiate conversation or create sentences. Terrace said that he had not noticed this throughout the duration of the study but only upon reviewing video tape. Terrace ultimately became a popularly cited critic of ape language studies.

Koko

Main article: Koko (gorilla)

In 1972, Francine "Penny" Patterson, inspired by a lecture she attended by Allen and Beatrix Gardner, began a program to teach sign language to a lowlands gorilla named Koko. Unlike the Gardners, she did not limit her English speech around Koko. Koko mastered approximately 1,000 signs before her death in 2018. But her well-publicized achievements ignited significant controversy among scientists, who questioned whether she was truly using a "language" or simply responding to Patterson's prompts. It is generally accepted that Koko did not demonstrate the use of syntax or grammar, key characteristics of language.

Plastic tokens

Sarah and two other chimpanzees, Elizabeth and Peony, in the research programs of David Premack, demonstrated the ability to produce grammatical messages of token selections. The selections came from a vocabulary of several dozen plastic tokens; it took each of the chimpanzees hundreds of trials to reliably associate a token with a referent, such as an apple or banana. The tokens were chosen to be completely different in appearance from the referents. After learning these protocols, Sarah was then able to associate other tokens with consistent behaviors, such as negation, name-of, and if-then. The plastic tokens were placed on a magnetic slate, within a rectangular frame in a line. The tokens had to be selected and placed in a consistent order (a grammar) in order for the trainers to reward the chimpanzees.

One other chimpanzee, Gussie, was trained along with Sarah but failed to learn a single word. Other chimpanzees in the projects were not trained in the use of the tokens. All nine of the chimpanzees could understand gestures, such as supplication when asking for food; similarly, all nine could point to indicate some object, a gesture which is not seen in the wild. The supplication is seen in the wild, as a form of communication with other chimpanzees.

A juvenile Sumatran orangutan Aazk (named after the American Association of Zookeepers) who lived at the Roeding Park Zoo (Fresno, California) was taught by Gary L. Shapiro from 1973 to 1975 how to "read & write" with plastic children's letters, following the training techniques of David Premack. The technique of conditional discrimination was used such that the orangutan could eventually distinguish plastic letter (symbols) as representations of referents (e.g., object, actions) and "read" an increasingly longer series of symbols to obtain a referent (e.g., fruit) or "write" an increasingly longer series of symbols to request or describe a referent. While no claim of linguistic competence was made, Aazk's performance demonstrated design features of language, many similar to those demonstrated by Premack's chimpanzee, Sarah.

Kanzi

Main article: Kanzi

Kanzi has learned hundreds of arbitrary symbols representing words, objects, and familiar people (including the generic "Visitor").

Kanzi, a bonobo, learned to communicate with a lexigram board at first by eavesdropping on the lessons researcher Sue Savage-Rumbaugh was giving to his adoptive mother. Kanzi used the lexigram board by pushing symbols that stand for words. The board was wired to a computer and symbols were vocalized out loud once pressed.

One day, Rumbaugh used the computer to say to Kanzi, "Can you make the dog bite the snake?" It is believed Kanzi had never heard this sentence before. In answering the question, Kanzi searched among the objects present until he found a toy dog and a toy snake, put the snake in the dog's mouth, and used his thumb and finger to close the dog's mouth over the snake. In 2001, Alexander Fiske-Harrison, writing in the Financial Times, observed that Kanzi was "asked by an invisible interrogator through head-phones (to avoid cueing) to identify 35 different items in 180 trials. His success rate was 93 percent." In further testing, beginning when he was 7+1⁄2 years old, Kanzi was asked 416 complex questions, responding correctly over 74% of the time. Kanzi has been observed verbalizing a meaningful noun to his sister.

Kanzi relies highly on the lexigrams for communication, and frequently uses them to specify where he wants to go, or an item he wants to have. He does this by expressing his goal (location or object) first, and his action (go, chase, carry, give, etc.) last. This notified researchers that Kanzi's way of communicating was different from that of spoken English, especially because Kanzi would communicate many of his action words using simple gestures. In addition, Kanzi is frequently seen linking two action words together using the lexigrams, like "I Tickle", "Chase Hide", or "Chase Bite". These word combinations are not necessarily structured in a way that humans would use spoken English, but they closely resemble lists, consisting of preferred actions, in preferred order of Kanzi's social play. Because of this inconsistency of Kanzi's use of language with the spoken English language, many question whether Kanzi's understanding of English "crosses the boundary with true language".

Question asking

Despite their impressive (although still sometimes disputed) achievements, Kanzi and other apes who participated in similar experiments, failed to ask questions themselves. Joseph Jordania suggested that the ability to ask questions is probably the central cognitive element that distinguishes human and animal cognitive abilities. (However, a parrot named Alex was apparently able to ask simple questions. He asked what color he was, and learned "grey" after being told the answer six times.) Enculturated apes, who underwent extensive language training programs, successfully learned to answer quite complex questions and requests (including question words "who", "what", "when", "where", and "why"), although so far they failed to learn how to ask questions themselves. For example, David and Anne Premack wrote: "Though she [Sarah] understood the question, she did not herself ask any questions – unlike the child who asks interminable questions, such as What that? Who making noise? When Daddy come home? Me go Granny's house? Where puppy? Sarah never delayed the departure of her trainer after her lessons by asking where the trainer was going, when she was returning, or anything else". The ability to ask questions is sometimes assessed in relation to comprehension of syntactic structures. Jordania suggested that this approach is not justified, as (1) questioning is primarily a cognitive ability, and (2) questions can be asked without the use of syntactic structures (with the use of specific intonation only). It is widely accepted that the first questions are asked by humans during their early infancy, at the pre-syntactic, one word stage of language development, with the use of question intonation.

Criticisms of language studies

Many researchers have presented evidence of linguistic abilities in nonhuman primates. Many of their conclusions have been disputed. It is now generally accepted that apes can learn to use signs and are able to communicate with humans. However, it is disputed as to whether they can form syntax to manipulate such signs.

Great apes can be said to "understand" (receive), and some can "apply" (produce) consistent, appropriate messages.

• Chimpanzees
• Bonobos
• Gorillas
• Orangutans

Primate language research uses sign language and computer keyboards because non-human primate have less tongue and lower jaw control and their vocal cords cannot close fully. However, primates do possess the manual dexterity required for keyboard use.

Linguistic critics challenged the animal trainers to demonstrate that Washoe was actually using language and not isolated symbols. The null hypothesis was that the Gardners were using operant conditioning to teach the chimpanzee to use hand formations in certain contexts to create desirable outcomes, and that they had not learned the same linguistic rules that humans innately learn.

Though Project Nim produced few meaningful results, scientists determined that non-human primates mimic what they see and memorize different practices' outcomes, and also that they have a higher likelihood of becoming dangerously aggressive when taken out of their natural habitat at a young age.

Some scientists, including MIT linguist Noam Chomsky and cognitive scientist Steven Pinker, are skeptical about claims made for great ape language research. Among the reasons for skepticism are the differences in ease with which human beings and apes can learn language; there are also questions of whether there is a clear beginning and end to the signed gestures and whether the apes actually understand language or are simply doing a clever trick for a reward.

While vocabulary words from American Sign Language are used to train the apes, native users of ASL may note that mere knowledge of ASL's vocabulary does not equate to knowledge of ASL.

Contemporary research

Among primates, autonomous behaviors such as body posture, facial expressions, vocalizations and scent production have been observed to convey information to other animals, revealing emotions or alerts about potential danger. Affiliative behaviors like grooming are used to promote group cohesion and individual status, while displays of aggression create divisions among groups. Humans, by contrast, have developed a reliance on verbal language. Primatologist Tetsuro Matsuzawa proposes in his cognitive tradeoff hypothesis that humans exchanged short-term and working memory for better language skills over their evolution.

See also

• Alex (parrot)
• Animal cognition
• Animal communication
• Animal language
• Animal training
• Biosemiotics
• Cognitive tradeoff hypothesis
• Human-animal communication
• Language – as it pertains to humans
• Language acquisition
• Operant conditioning
• Origin of language
• Primate cognition
• Proto-language (glottogony)
• Theory of mind
• Yerkish

Researchers

• Roger Fouts
• Francine Patterson
• David Premack
• Sue Savage-Rumbaugh

Research subjects

• Ai (chimpanzee)
• Chantek (orangutan)
• Kanzi (bonobo)
• Lana (chimpanzee)
• Koko (gorilla)
• Lucy (chimpanzee)
• Nim Chimpsky (chimpanzee)
• Panbanisha (bonobo)
• Sarah (chimpanzee)
• Washoe (chimpanzee)
• Viki (chimpanzee)

References

• Fouts, Roger; Mills, Stephen Tukel (1997). Next of Kin: What Chimpanzees Have Taught Me About Who We Are. New York: William Morrow. ISBN 0-688-14862-X.
• Hess, Elizabeth. (2008). Nim Chimpsky: The Chimp Who Would Be Human. New York: Bantam. ISBN 9780553803839.
• Hillix, W.A.; Rumbaugh, Duane (2013) [2004]. Animal Bodies, Human Minds. Developments in Primatology: Progress and Prospects. Springer. ISBN 978-1441934000.
• Linden, Eugene (1974) Apes, Men, and Language: How teaching chimpanzees to "talk" alters man's notions of his place in nature. New York: Saturday Review Press/E. P. Dutton & Co. ISBN 0-8415-0343-5.
• Linden, Eugene (1986). Silent Partners: The Legacy of the Ape Language Experiments. Times Books. ISBN 0-8129-1239-X.
• Patterson, Francine; Linden, Eugene (1981). The Education of Koko. New York: Holt, Rhinehart and Winston. ISBN 0030461014.
• Premack, David (2015). Intelligence in Ape and Men. Psychology Revivals. Psychology Press. ISBN 978-1848722644.
• Terrace, H. S. (1979). Nim. New York: Knopf.

External links

• GaTech.edu Archived 7 February 2008 at the Wayback Machine – "Animal Communication" (from the book Language Files, Sixth Edition), editors: Stefanie Jannedy, Robert Poletto, Tracey L. Weldon, Department of Linguistics Ohio State University (1994)
• Great Ape Trust - "Use of Human Languages by Captive Great Apes" from the book World Atlas of Great Apes and Their Conservation by Duane Rumbaugh, Sue Savage-Rumbaugh and William Fields (2005)
• Thailand tree apes use song as warning
• Orangutans mime to get message across
• Books by Richard Garner: The Speech of Monkeys (1892), Gorillas & Chimpanzees (1896), and Apes and Monkeys: Their Life and Language (1900).