Hanabiko "Koko" (July 4, 1971 – June 19, 2018) was a female western lowland gorilla known for having learned a large number of hand signs from a modified version of American Sign Language (ASL). Koko was born at the San Francisco Zoo and lived most of her life in Woodside, California, at The Gorilla Foundation's preserve in the Santa Cruz Mountains. The name "Hanabiko" (花火子), lit. 'fireworks child', is of Japanese origin and is a reference to her date of birth, the Fourth of July. Koko gained public attention upon a report of her having adopted a kitten as a pet and creating a name for him.
Her instructor and caregiver, Francine Patterson, reported that Koko had an active vocabulary of more than 1,000 signs of what Patterson calls "Gorilla Sign Language" (GSL). In contrast to other experiments attempting to teach sign language to non-human primates, Patterson simultaneously exposed Koko to spoken English from an early age. It was reported that Koko understood approximately 2,000 words of spoken English, in addition to the signs. Koko's life and learning process has been described by Patterson and various collaborators in books, peer-reviewed scientific articles, and on a website.
As with other great-ape language experiments, the extent to which Koko mastered and demonstrated language through the use of these signs is disputed. It is generally accepted that she did not use syntax or grammar, and that her use of language did not exceed that of a young human child. However, she scored between 70 and 90 on various IQ scales, and some experts, including Mary Lee Jensvold, claim that "Koko...[used] language the same way people do".
Koko was born on July 4, 1971, at the San Francisco Zoo to her mother Jacqueline and father Bwana. Koko was the 50th gorilla born in captivity and one of the first gorillas accepted by her mother in captivity. Koko remained with her mother until the age of one when she was taken to the zoo's hospital to be treated for a life-threatening illness. Patterson originally cared for Koko at the San Francisco Zoo as part of her doctoral research at Stanford University after Koko came to the zoo's hospital. Koko was loaned to Patterson under the condition that she would spend at least 4 years with her. Eventually, Koko remained with Patterson, supported by The Gorilla Foundation, which Patterson founded to support gorilla research and conservation.
After Patterson's research with Koko was completed, the gorilla moved to a reserve in Woodside, California. At the reserve, Koko lived with another gorilla, Michael, who also learned sign language, but he died in 2000. She then lived with another male gorilla, Ndume, until her death. Koko's weight of 280 pounds (127 kg) was higher than would be normal for a gorilla in the wild, where the average weight is approximately 150–200 pounds (70–90 kg), but the foundation stated that Koko "is, like her mother, a larger frame Gorilla".
In 1978, Koko gained worldwide attention as she was pictured on the cover of National Geographic magazine. The cover picture was an image of Koko taking her own picture in the mirror. Koko was later featured on the cover of National Geographic in 1985 with a picture of her and her kitten, All-Ball. At the preserve, Koko also met and interacted with a variety of celebrities including Robin Williams, Fred Rogers, Betty White, William Shatner, Flea, Leonardo DiCaprio, Peter Gabriel, and Sting.
Koko was reported to have a preoccupation with both male and female human nipples, with several people saying that Koko requested to see their nipples. In 2005, three staff at The Gorilla Foundation, where Koko resided, filed lawsuits against the organization, alleging that they were pressured to reveal their nipples to Koko by the organization's executive director, among other violations of labor law. The lawsuits were settled out of court. Gorilla expert Kristen Lukas has said that other gorillas are not known to have had a similar nipple fixation.
Koko died in her sleep during the morning of June 19, 2018, at the Gorilla Foundation's preserve in Woodside, California, at the age of 46. The Gorilla Foundation released a statement that "The impact has been profound and what she has taught us about emotional capacity of gorillas and their cognitive abilities will continue to shape the world." Even though Koko was 46 years old when she died, well past the average life expectancy of a gorilla, her death took staff members of the Gorilla Foundation by surprise.
Patterson reported that Koko made several complex uses of signs that suggested a more developed degree of cognition than is usually attributed to non-human primates and their use of communication. For example, Koko was reported to use displacement (the ability to communicate about objects that are not currently present). At age 19, Koko was able to pass the mirror test of self-recognition, which most other gorillas fail. She had been reported to relay personal memories. Koko was reported to use meta-language, being able to use language reflexively to speak about language itself, signing "good sign" to another gorilla who successfully used signing. Koko was reported to use language deceptively, and to use counterfactual statements for humorous effects, suggesting an underlying theory of other minds.
Patterson reported that she documented Koko inventing new signs to communicate novel thoughts. For example, she said that nobody taught Koko the word for "ring", but to refer to it, Koko combined the words "finger" and "bracelet", hence "finger-bracelet".
Also, Koko referred to herself as a "queen" at times even though Patterson rarely used this word with Koko. Many researches have speculated that Koko was projecting her awareness that she was famous because of all the attention she received from her care-givers, professors, the media and her fans.
Criticism from some scientists centered on the fact that while publications often appeared in the popular press about Koko, scientific publications with substantial data were fewer in number. Other researchers argued that Koko did not understand the meaning behind what she was doing and learned to complete the signs simply because the researchers rewarded her for doing so (indicating that her actions were the product of operant conditioning). Another concern that has been raised about Koko's ability to express coherent thoughts through signs is that interpretation of the gorilla's conversation was left to the handler, who may have seen improbable concatenations of signs as meaningful. For example, when Koko signed "sad" there was no way to tell whether she meant it with the connotation of "How sad". Following Patterson's initial publications in 1978, a series of critical evaluations of her reports of signing behavior in great apes argued that video evidence suggested that Koko was simply being prompted by her trainers' unconscious cues to display specific signs, in what is commonly called the Clever Hans effect.
Between 1972 and 1977, Koko was administered several infant IQ tests, including the Cattell Infant Intelligence Scale and form B of the Peabody Picture Vocabulary Test. She achieved scores in the 70–90 range, which is comparable to a human infant that is slow but not intellectually impaired. According to Francine Patterson, however, it is specious to compare her IQ directly with that of a human infant because gorillas develop locomotor abilities earlier than humans and many IQ tests for infants require mostly motor responses. Gorillas and humans also mature at different rates, so using a gorilla's chronological age to compute their IQ results in a score that is not very useful for comparative purposes.
Researchers at The Gorilla Foundation said that Koko asked for a cat for Christmas in 1983. Ron Cohn, a biologist with the foundation, explained to the Los Angeles Times that when she was given a lifelike stuffed animal, she was less than satisfied. She did not play with it and continued to sign "sad". So on her birthday in July 1984, she was able to choose a kitten from a litter of abandoned kittens. Koko selected a gray male Manx and named him "All Ball". Penny Patterson, who had custody of Koko and who had organized The Gorilla Foundation, wrote that Koko cared for the kitten as if it were a baby gorilla. Researchers said that she tried to nurse All Ball and was very gentle and loving. They believed that Koko's nurturing of the kitten and the skills she gained through playing with dolls would be helpful in Koko's learning how to nurture an offspring.
In December 1984, All Ball escaped from Koko's cage and was hit and killed by a car. Later, Patterson said that when she signed to Koko that All Ball had been killed, Koko signed "Bad, sad, bad" and "Frown, cry, frown, sad, trouble". Patterson also reported later hearing Koko making a sound similar to human weeping.
In 1985, Koko was allowed to pick out two new kittens from a litter to be her companions. The animals she chose, which she named "Lipstick" and "Smoky", were also Manxes. Koko picked the name after seeing the tiny orange Manx for the first time. When her trainer asked the meaning of the name, Koko answered, Lips lipstick.
To celebrate her birthday in July 2015, Koko was presented another litter of kittens. Picking two, she named them Miss Black and Miss Grey.
Koko and Patterson's work with her have been the subject of several books and documentaries.
The Gorilla Foundation said the 280-pound (127-kilogram) western lowland gorilla died in her sleep at the foundation’s preserve in California’s Santa Cruz mountains Tuesday.
[NETBURN:] Did Koko use language like humans do? [JENSVOLD:] Koko and the other signing apes absolutely use language the same way people do. She was commenting on the world around her and signing about her activities, her day and her thoughts. I liken it to talking to a child—not because she wasn't mature, but because she was in a dependent relationship. The conversation you would have with her is like the conversation you would have with a child or an elderly person in your care.
Following the article, the book Koko's Kitten was published and continues to be used in elementary schools worldwide. Her impact has been profound and what she has taught us about the emotional capacity of gorillas and their cognitive abilities will continue to shape the world.
Joy Chesbrough, the foundation's chief development officer, told The Times that Koko 'went peacefully' and that, despite her advanced age, her death was unexpected. Staff members were taking the loss hard, Chesbrough said.
Koko picked the name after seeing the tiny orange Manx for the first time. When her trainer asked the meaning of the name, Koko answered, Lips lipstick. Patterson was confused until she realized that Lips had a pink nose and mouth, unlike All Ball's gray markings. Koko picked Smoky's name because the kitten looked like a cat in one of the gorilla's books, she said Wednesday.
See also: Animal language § Further reading