Koko – the smartest gorilla in the world

Hanabiko Koko – the most intelligent gorilla in the world

The talking gorilla – the story of Koko

Many people want to understand animals. Communication is of course the key – unfortunately no animal can speak in our understanding of the word. The exception is the great apes that can be taught sign language. This is what happened with the gorilla Koko, who became famous for learning more signs than any other gorilla or chimpanzee.

Koko lived most of her life in Woodside, California, at the headquarters of the Gorilla Foundation, which deals with communication with primates. Her guardian, Francine Patterson, had been teaching her sign language since childhood. Gorilla understood over 2000 signs of the so-called ASL (American Sign Language). However, this is not the only thing that made Koko amaze the world – the gorilla made many scientists look at animals differently than before.

Hanabiko “Koko” gorilla

Koko’s biography

Koko was born on July 4, 1971 in the San Francisco Zoo. She was exactly the 50th captive-born gorilla. She stayed with her mother until she became independent, and was then taken to a clinic, where she underwent extensive tests to cure her of any fatal diseases. Then Koko went to a foundation founded by Francine Patterson. She stayed there for 4 years, during which intensive research into her communication skills was carried out.

After completing her research, Koko ended up in a Woodside reserve. There she lived with a gorilla named Michael, who also learned sign language. After he died in 2000, she married a gorilla named Ndume with whom she lived until her death. Koko died in her sleep on June 19, 2018 at the age of 46. Despite her old age for a gorilla, her death surprised the Foundation’s employees, as she was in perfect health and condition.

Hanabiko “Koko” gorilla

Koko and ASL (American Sign Language)

The attempts to teach the great apes to speak humanly are not new. At the turn of the 1940s and 1950s, Keith and Cathy Hayes kept at home the chimpanzee Viki, who had learned to pronounce four words. Often she gesticulated strongly, trying to make her understand what she meant. It was a clear signal for scientists that learning human speech did not make sense here, because primates are not equipped with the necessary organs – and the solution was sign language. The discovery of this fact was a breakthrough in communication with animals. It turned out that gorillas and chimpanzees learn sign language relatively easily.

Koko is so far the record holder among “nonhumans”, having mastered the ability to show over 1,000 ASL characters and recognized over 2,000. She began to practice science when she turned one. Patterson emphasized that the skills and dexterity of her ward far exceeded the skills that had previously been awarded to apes. Koko was able, among other things, to invent her own words when the resource of characters she mastered, lacked an appropriate ALS sign. For example, she knew the gesture for a finger and another for a bracelet. So when she showed the two marks one by one, she meant a ring on her finger.

Hanabiko “Koko” gorilla

Koko and the world of science

This is not the end of Koko’s achievements. At the age of 19, she amazed the world of science by passing the so-called mirror test. It turned out that she recognizes herself in the mirror and does not consider herself to be another gorilla. It also turned out that he can talk about his memories and recall facts from his past. Moreover, she was also able to express her state of well-being, which in turn was the basis for scholars to argue that Koko had a sense of being aware of her own existence.

Of course, questions arose at this point about her intelligence. In the years 1972-77, a number of studies on intelligence were carried out, which showed that Koko’s IQ ranges from 70-90. This meant that the gorilla’s IQ was higher than that of a mentally retarded person, and it was at the level of a healthy child. But Patterson argued that performing intelligence tests on gorillas was of little help, because gorillas and humans mature differently, and that comparisons like these don’t make sense.

Hanabiko “Koko” gorilla


Of course, not all scholars were equally enthusiastic about Koko and her achievements. Some have suggested that it was not possible to say unequivocally that the gorilla actually describes her feelings. They also suspected that Koko was showing certain signs on pre-arranged signals or under certain circumstances. They cited, inter alia, the famous example of “intelligent horse” Hans, who allegedly knew how to solve mathematical problems – which, however, turned out to be a hoax developed by his guardians.

In the case of Koko, however, no one has proven that a similar fraud was committed. The guardians of Koko and her supporters themselves accused skeptics that their negative opinion about gorillas was only due to their reluctance to admit that gorillas could display psychological traits previously attributed only to humans. This would mean the necessity to change gorillas’ worldview and perception – also in the light of the law. Therefore, Koko’s achievements and the insights of her guardians ultimately went unchallenged.

Hanabiko “Koko” gorilla

Koko – cat mom

Koko showed great interest in cats. In 1983, she expressed the wish that she wanted to receive a cat for Christmas. Initially, she was given a stuffed animal, to which the gorilla became depressed, still showing the gesture for “sad”. Therefore, for her birthday in 1984, she got a Manx cat, which she named herself – “All Ball”. The keepers noticed that Koko is extremely gentle and caring towards the cat, showing similar behaviors, as if she was taking care of her baby. At the same time, she realized that the cat was not a toy – she treated it completely differently than, for example, human dolls.

In December of the same year, the cat ran away from the room and fell under the car. Patterson showed Koko that the pet had died, to which the gorilla responded by showing a series of “sad, bad, sad” and “cry, upside down” signs. For the next few days, Koko was lethargic and made sounds similar to human crying.

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In 1985, Koko was led to a cluster of cats, out of which she chose two. She also named them herself – Lipstick and “Smoky”. She got more cats for her birthday in 2015. This time she called them Miss Black and Miss Gray. They accompanied her until the end of her life.

Hanabiko “Koko” gorilla

Koko – a celebrity

Koko first caught the attention of the world in 1978, when National Geographic published a picture of her in front of her reflection in a mirror. Once again, this magazine featured a photo of her in its 1985 issue, showing Koko and the cat All-Ball, to whom the gorilla paid a lot of attention. This second photo in particular made people understand that gorillas can display similarly human protective instincts for animals that are neither their caretakers nor a source of food for them – but they are household companions.

While at Woodside, Koko met many famous figures from the world of film and music, including Robin Williams, Leonard DiCaprio, Peter Gabriel and Sting. She spoke to each of the guests in sign language, through a human interpreter who knew ASL.

Gorilla has also become an object of interest in the media world. Already in 1978, a documentary about her was made, “Koko: A Talking Gorilla”. Based on the history and skills of the gorilla, the famous writer Michael Crichton wrote the novel “Congo”, the heroine of which was Amy the gorilla, modeled on Koko. Over the years, a number of articles were written and many documentaries were made of her conversations with people and the way she dealt with her favorite cats.

Hanabiko “Koko” gorilla

Koko – interesting facts

  • Koko is the short form for Japanese Hanabi-Ko (花火子), which means “fireworks child” and refers to her birthday, the Independence Day of the United States on July 4th.
  • Koko showed an inexplicable, immense fascination with human nipples – male and female. She liked to watch them very much and repeatedly asked visitors, to undress from the waist up and let her look.
  • Koko was exceptionally large for a gorilla – she weighed 127 kg, while the wild ones weigh up to 90 kg. In captivity, however, it is not unusual – animals have enough food and less exercise than in the wild.
Hanabiko “Koko” gorilla with mirror


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