Animal Consciousness: A Controversy

Jamie Randol

            “Come here. I love you. I’m sorry. I want to go back,” were the words of Alex, an African gray parrot, when his owner and trainer left him with a vet for treatment. Alex had mastered the ability to speak, but did he truly understand the meaning of his words or was he simply repeating sounds without comprehension? Can any nonhuman animal truly understand the meaning of language? The debate over animal consciousness stems from this question. Consciousness, however, does not have a strict definition and is based on a completely subjective experience, not viewed in the third person; therefore is not easily identified. As a result, we must rely upon a host of behavioral cues to determine consciousness. We readily accept human consciousness based on an individual’s ability to understand language and show human attributes such as mourning, deceitfulness, and empathy. By these standards, any animals displaying these abilities are rightfully conscious as well. Both Kanzi the bonobo and Koko the gorilla use language to communicate needs, desires, and ultimately animal consciousness.

 Through evolution, language has become a vital part of our culture; many critics believe our ability to use language is what distinguishes man from ape. Philosopher and linguist, Avram Noam Chomsky, maintains that there is a qualitative difference between advanced human language and animal communication. He points to the similarity in grammar of all human language and suggests there is an apparatus called the Language Acquisition Device (LAD) that is unique to humans, which prevents animals from understanding or acquiring human language (Lund, 81). Ape Language Research, ALR, challenges this view by training great apes to use language and suggests that there is not an unbridgeable divide between humans and the rest of the animal kingdom, but rather a “gradation of linguistic skills” (Johnson).

One of the most emphatic rebuttals to Chomsky’s thesis comes in the form of Kanzi. Kanzi is a bonobo or “pygmy chimpanzee” who is not only the first of his kind to understand language but is also the first of all great apes to have learned aspects of language naturalistically, rather than through direct training. Originally, primatologist Sue Savage-Rumbaugh sought to teach Kanzi’s mother, Matata, human language through keyboard lexigrams. Matata showed neither progress nor interest. To Savage-Rumbaugh’s surprise Kanzi, who would accompany his mother to lexigram lessons, one day spontaneously and competently, used the lexigram system. Savage-Rumbaugh’s attention therefore shifted to Kanzi and a new training method.

Instead of teaching words and sentences to apes, Savage-Rumbaugh would give Kanzi a reason to talk. She says Kanzi needed "a world that would foster the acquisition of these lexical symbols […] and a greater understanding of spoken human language” (Hamilton). This was a world where Kanzi would learn the way human babies do; he would eat and play with his human friends and participate in his favorite activities, most notably hiking around his 50-acre home. These methods led to success. Before long, Kanzi had mastered more than two hundred words and was able to use language in a way similar to humans. He would talk about places and object that were not in sight, refer to the past and future, and understand new sentences made up of familiar words (Hamilton).

According to Smithsonian Magazine, November 2006, Kanzi has now learned over 348 lexigrams and understands over 3000 spoken English words. To assess Kanzi’s understanding of the symbols, Savage-Rumbaugh uses specific testing methods to avoid inadvertent cuing. For example, Kanzi listens to test question through headphones so Savage-Rumbaugh cannot hear the question nor give clues about the correct answer. Under these circumstances, Kanzi points to the correct lexigram corresponding to the given question. In other testing, Savage-Rumbaugh uses a metal welding mask to cover her facial expressions while asking Kanzi to perform unlikely tasks that demonstrate understanding. For instance, she may ask him to “put the pine needles in the refrigerator” or “carry the T.V. outdoors” (Raffaele). Nearly every time, Kanzi responds with the appropriate action.

            Kanzi has demonstrated his understanding and ability to communicate on many occasions. On an outing in the woods, Kanzi touched the symbols for “marshmallow” and “fire” on his lexigram table. Given matches and marshmallows, he then snapped twigs for a fire, lit them with the matches, and toasted the marshmallows on a stick (Raffaele). Kanzi thought about roasting marshmallows and was able to use his keyboard to communicate his desire, a basic application of language that shows real comprehension.

            One important goal of language acquisition is to give apes the tools to not only communicate with human handlers, but with others of the ape species as well. In an experiment, Kanzi was placed in a room and shown a jar of yogurt. He started vocalizing “yogurt” in an unknown tongue to another bonobo who then pointed to the lexigram for yogurt (Raffaele). His ability to relay information correctly to other of his species, again, illustrates an understanding of the concepts and words that Savage-Rumbaugh had been teaching.

Many observers believe that Kanzi’s accomplishments provide “solid evidence of being able to communicate simple thoughts, desires, and even intentions.” In addition, his ability to combine lexigram symbols in regular ways is a sign of a limited use of “protogrammar,” equivalent to that of a two-and-a-half-year-old human child (Page, 153). Interestingly, grammar is a major component of the argument against ape language acquisition. Kanzi’s use of grammar helps eradicate the idea that language is a purely human ability.  

Like Kanzi the bonobo, Koko the gorilla was the first of her species to acquire language abilities. Through Project Koko, Dr. Francine Patterson was able to teach Koko American Sign Language, or Amslan, to communicate her needs and personality. Patterson had a dual role as scientist exploring the nature of animal language and as surrogate mother to the young Koko. Therefore, like Kanzi, Koko was taught in a nurturing environment, similar to that of a human infant. Koko lived in a trailer, had her own room, a kitchen, and a living room, and of course a set of adoring “family” members, who would aid in the project. In this setting, Patterson began to shape and mold Koko’s hands to resemble Amslan signs that would correspond with an object or idea under observation. To Patterson’s delight the young gorilla showed understanding almost immediately.

Koko would spontaneously use signs like “food”, “drink”, and “more” to convey her desires.  A couple months into the program, Koko defied critics by asking questions, an ability previously thought to pertain only to humans since it requires understanding and conscious thought. She would cock her head, raise her eyebrows, and maintain eye contact while signing. Koko now communicates with more than 1,000 signs. On many occasions Koko would create her own version of Amslan signs that she was otherwise unable to form with her hands. A gorilla’s hands are not only larger and less dexterous than those of a human, but the thumb is located lower on the hand, preventing the thumb and fingers from coming together properly to form some signs. Koko was able to assign meaning to signs she created herself.

One of mankind’s distinguishing traits is his ability to use old concepts to create or define new concepts. In a similar way, Koko is able to combine two or more common signs to describe a new object. When presented with a ring for the first time, she signed “finger bracelet,” two words she had previously learned to describe the unfamiliar ring. Another of Koko’s compound name innovations is “fruit lollipop” to describe a frozen banana treat (Linden, 101). Koko’s ability to combine signs in a coherent manner to describe unfamiliar objects indicates her true understanding of the component signs and a higher level of thinking. She is not only understanding, but also manipulating words to form novel ideas. 

Koko’s most remarkable use of language is her ability to rhyme. When given a word in English, she can sign a different word that when spoken rhymes with the first.

In a test, toy animals were arranged in a row in front of Koko, who was asked questions about them. When asked, “Which animal rhymes with hat?” Koko responded, “Cat.” For “Which rhymes with big?” Koko pointed to the toy pig. On another occasion, Koko was asked, “Can you do a rhyme?” Koko obligingly generated the signs “hair bear” and then “all ball” (Linden, 141). It is clear that Koko is understanding and translating to and from English to sign. Rhyming couples words that are otherwise unrelated by sound. For Koko to generate rhymes she must understand English since there is not a comparable idea in Amslan. 

            One of Koko’s greatest accomplishments was in the comprehension of spoken English. Not only was Koko able to use sign to communicate, she surprised Patterson by understanding human speech, which Chomsky declared to be impossible. The first notable instance of English comprehension occurred when Koko spontaneously signed  candy” after having heard a visitor mention the word to Patterson. Subsequently, Koko would regularly translate English words and phrases that she heard. She also began to answer questions. One day a visitor asked what the sign for “good” was. Before Patterson could respond, Koko was making the sign (Linden, 100).  Koko is now reported to understand more than 2,000 spoken English words.               

            In order to formally check Koko’s language abilities, Patterson tested the gorilla through double blind methods and administered several accepted human language tests, including IQ tests. During double blind testing, Koko could see an object but not the test administrator. In turn, the administrator could see Koko but not the object. Koko would then be asked to name the object. The administrator would record Koko’s responses. At the end of the test, the objects would be revealed and Koko’s responses would be analyzed for correctness. Her scores were usually between 90 and 100 percent. Patterson also administered tests such as the ACLC, “Assessment of Children’s Language Comprehension,” that examined Koko’s knowledge of vocabulary and comprehension of phrases. Again, Koko scored impressively. Her level of comprehension is comparable to that of handicapped children, which for a gorilla is excellent (Linden, 104). On IQ tests, Koko’s scores are consistently in the 70 to 90 range on different IQ scales, where average human intelligence is 100 (Linden, 127).

            Both Kanzi and Koko have demonstrated their grasp of language; however, man’s ability to use language is not the only attribute that characterizes him as conscious. Another defining feature is our ability to insult, lie, have a sense of self, and show empathy.

            Koko uses language to express many of these human attributes. Her favorite way to express anger or impatience is through insults. As Patterson put its, “in being ‘bad,’ Koko can be very, very good” (Linden, 6). Insulting is a way of showing inner personality and thought.  On one occasion, when asked, “What’s this?” about a picture of Koko, she signed “gorilla.” “Who gorilla?” asked the handler. “Bird” responded Koko. By this time it was known that Koko disliked birds and used the word when she was displeased. When asked, “You bird?” Koko countered “you,” “me gorilla,” “you nut” (Linden, 6). Koko also refers to Ron Cohn, an affiliate of Project Koko, as “Stupid devil” or “devil head.” (Linden, 139). Koko is aware of Ron’s position of dominance in the program and resents it. She therefore, gets back at Ron with words.

            Koko is also known to lie. Koko’s first apparent lie involved blaming one of her handlers, Kate, for something Koko had done. At age three, Koko was asked, “Who broke this [toy] cat?” Koko replied, “Kate cat.” It was clear that Koko knew she had broken the toy but chose to blame the damage on Kate. On a separate occasion, when Koko was five, she was playing a game of chase with a handler. In her excitement, Koko bit the handler when he caught her. “What did you do?” Patterson demanded. “Not teeth,” was her explanation. “Koko, you lied!” Patterson replied. “Bad again Koko bad again,” admitted Koko (Linden, 181). Here Koko illustrates her ability to deceive, but more importantly, her knowledge that lying is wrong.

            On many occasions Koko has demonstrated a sense of self. She not only able to recognize herself in a photo and put lipstick on in a mirror, but she has opinions about herself as well. For example, a visitor stopped by to see Koko. On meeting, the visitor pointed to Koko and them made a small circle with her open hand in the air in front of her own face, signing, “You’re pretty.” Koko then stroked her finger across her nose; a sign meaning false or fake (Linden, 3).  Koko’s response can be seen as an indication of modesty or a comment on her visitor’s sincerity. Either way, Koko must have a sense of who she is in order to respond in that manner.

             Most notably, Koko is able to show empathy. After overhearing her handlers discuss the 9-11 tragedy, Koko became quite anxious. Patterson asked, “Why are you upset?” Koko replied, “Feel very sorry” followed by a big audible sigh. Patterson asks, “talk about the trouble?” Koko utters, “man cut-neck, know takeoff” (The Gorilla Foundation). “Cut-neck” is Koko way of discussing death. In previous years, Koko was partnered with another signing gorilla named Michael, who had lost his parents to poachers. Michael used “cut-neck” to talk about his parents’ death. Koko has since picked up the sign.

            Critics most commonly use the “Clever Hans” phenomenon to discount animal language acquisition. Clever Hans was a wonder horse in Germany who surprised his owner with his ability to count and do simple math problems. By blindfolding the horse, critics discovered that Hans would simply start tapping his foot while watching his owner, who would innocently and almost imperceptibly straighten up when Hans reached the correct answer, and would then stop tapping. In the same way, critics claim that apes may look like they are understanding language, but their trainers must be giving them inadvertent cues.

            These accusations, however, are incorrect. Not only do the testing methods employed by Kanzi’s trainer, Dr. Savage-Rumbaugh, and Koko’s trainer, Dr. Francine Patterson, prevent cueing by the instructor, both animals have demonstrated an understanding of language far beyond simple mimicry. Savage-Rumbaugh used headphones and welding masks to hide her facial expressions and Patterson used double blind testing. In addition, Hans’s cues required tap/no tap decisions, where Kanzi and Koko’s options are hundreds of signs or thousands of sign combinations.

            Another critique deals with the motor theory of speech theory. Several scientists believe that if an animal could not generate spoken words, it did not have the necessary equipment to understand them either. Both Kanzi and Koko’s accomplishments defy this theory by accurately completing tasks given to them in spoken English. Kanzi is able to follow direction such as “place the pine needles in the refrigerator” and Koko correctly signs the name of an object when verbally asked, “What is that?”

            Critics also argue that understanding human language involves more than communication. Word order and grammar play an important role as well. In this case, Kanzi has shown knowledge of some form of “protogrammar.” Koko, who converses in American Sign Language, does not necessarily need to use grammar or word order. In sign language it is much easier to represent a whole thought simultaneously, by making more than one gesture at a time or by combining gestures. This in nature is completely different from linear English (Linden, 117). Some scientists have gone as far as claiming Amslan is not a language, therefore Koko cannot and does not communicate in language. This however, implies that the deaf are not human. If language distinguishes man from beast, those who communicate through Amslan do not satisfy the criteria for being human. Clearly, this is absurd: deaf individuals are indubitably human and are using language. Therefore, animals communicating in Amslan are also using language.

            Thomas Kuhn, a scientific philosopher, describes a trend in science. “When the alternative explanation of [an] anomaly appears, science does not then change by mass conversion. Rather, adherents of the old idea and the new idea exist side by side for a time, until ultimately those holding the old idea die out and are succeeded by scientists educated under the new view of things. Thus science proceeds by revolution” (Linden, 25). It is consequently only a matter of time before science will fully accept the implications of animal language. Once animal acquisition of language is accepted, recognition of animal consciousness will follow. Kanzi and Koko’s ability to use language and show truly human characteristics, such as deceit and empathy, classify them as conscious. Moreover, any animal exhibiting these behaviors is necessarily conscious, whether parrot, bonobo, gorilla, or human.

Works Cited

Hamilton, Jon. “A Voluble Visit with Two Talking Apes.” NPRonline. 8 July 2006. 14 Dec 2007.<>.

Hillix, W.A., and Duane Rumbaugh. Animal Bodies, Human Minds. New York, NY:  Plenum Publishers, 2004.

Johnson, George. “Chimp Talk Debate: Is it Really Language?” 6 June 1995. 14 Dec  2007. <>.

Kowalski, Gary. The Souls of Animals. Walpole, NH: Stillpoint Publishing, 1991

Linden, Eugene, and Francine Patterson. The Education of Koko. New York, NY: Holt,  Rinehart and Winston, 1981.

Lund, Nick. Animal Cognition. New York, NY: Taylor and Francis Inc., 2002.

Page, George. Inside the Animal Mind. New York, NY: Random House, Inc., 1999

Patterson, Francine. “Koko responds to 9-11 (Part 2).”The Gorilla Foundation. 28 Nov 2001. 14 Dec 2007.<>.

Raffaele, Paul. “Speaking Bonobo.” Smithsonian Magazine online. Nov 2006. 14 Dec 2007.<>