Koko, the so-called “talking ape,” died in her sleep on June 19, 2018, prompting a resurgence of discussion about her ability to use human language. As a result of her death there appears to be “credulous repetition of Koko’s mythical prowess in sign language…everywhere.”1 Research into animal communication is important because one major problem evolutionists face is explaining the origin of human language. Only humans have the innate ability to use a verbal vocabulary of thousands of words.

One of the strongest challenges to human language were the achievements of Koko—a female gorilla its keepers claimed learned a large number of hand signs using modified American Sign Language.2 Her teacher, Francine Patterson, claimed Koko was able to understand over 1,000 signs.3 In contrast to other experiments going back some 40 years attempting to teach sign language to primates, Patterson claimed to have succeeded.4 The Gorilla Foundation wrote that her work “has been profound” in “what she has taught us about the emotional capacity of gorillas and their cognitive abilities.”5

Critics of Patterson’s Claim

Geoffrey Pullum, a Professor of General Linguistics at the University of Edinburgh, claims a Time magazine reporter was “unusually extreme in its blend of emotion, illogicality, wishful thinking, and outright falsehood” about Koko.1 The gorilla “once made a sequence of hand signs that Patterson interpreted as ‘you key there me cookie’” that Time calls “impressive…for the clarity of its meaning.”6 What her keeper interpreted this to mean was “use your key to open the cabinet and get a cookie for me” which could also mean “You are the key to me getting a cookie.”

Patterson wrote a book based on her Stanford Ph.D. dissertation. A review of it confirms Pullum’s critique. Koko strung a few signed words together that must be arranged to be meaningful.7 The problem is that none of the 120 combinations of the words cookie, key, me, and there can be arranged to make a grammatically correct sentence. As with other ape language experiments, the extent to which Koko mastered and demonstrated language by the use of signs has been disputed.

For Patterson, any order Koko chose provided evidence of linguistic command. The lack of a verb in this case was common in the examples Patterson provided in her book on Koko. Others observed that Koko learned to sign simply because the researchers rewarded her for doing so, indicating she applied the same conditioning used to train rats.8 This is not unusual. Dogs and horses have been trained the same way to respond appropriately to hundreds of spoken words. No ape has succeeded in stringing words together to form a complete grammatically recognizable sentence.

Video evidence suggested Koko was being prompted by her trainers’ unconscious cues to display specific signs in a behavior called the Clever Hans effect.9 Hans was a horse able to solve math problems by tapping out the answer with his leg. It turned out that his trainer was providing unconscious subtle clues to stop tapping when the answer was reached.

It appears the claims of a talking ape were mostly hype. Koko was a smart ape, trained by her trainers to mimic human language, but she couldn’t really talk.

1. Pullum, G. 2018. Koko Is Dead, but the Myth of Her Linguistic Skills Lives On. The Chronicle of Higher Education. Posted on chronicle.com June 27, 2018, accessed August 17, 2018.
2. Patterson,  F. 1981. The Education of Koko. New York: Holt Rinehart & Winston.
3. Fischer, S. R. 1999. A History of Language.  London: Reaktion Books, 26–28.
4.  Examples include: Laidler, K. 1980. The Talking Ape (about an orang named Cody). New York: Stein and Day, and: Terrace, H. 1979. Nim: A Chimpanzee who Learned Sign Language. New York: Knopf.
5.  Gorilla Foundation Press release. June 20, 2018.
6. Kluger, J. Koko the Gorilla Wasn’t Human, But She Taught Us So Much About Ourselves. Time. Posted on time.com June 21, 2018, accessed August 18, 2018.
7. Pullum, G. 2018.
8. Candland, D.  1993. Feral Children and Clever Animals. New York: Oxford University Press, 293–301.
9.  Petitto, L. A., Seidenberg, M. S. 1979. On the evidence for linguistic abilities in signing apes. Brain and Language. 8(2): 162-183.

Dr. Jerry Bergman is Research Associate at the Institute for Creation Research and was an Adjunct Associate Professor at the University of Toledo Medical School in Ohio.