Born in 1976 (estimated)


A female chimpanzee Ai was born in West Africa on October 1976 (estimated).
Ai has arrived at the Primate Research Institute.
Ai has arrived at Primate Research Institute, Kyoto University(KUPRI) on November 1977. It was when she was 1 year of age, before Japan ratified CITES.
Akira and Mari have arrived at KUPRI on January 1978.
On 15th of April, the chimpanzee Ai participated in a computer task for the very first time.
We published the first paper that was written in English in a peer-reviewed journal. Ai, who learned names and colors of objects by using lexigram, made a sensation in academic world.
T. Asano, T. Kojima, T. Matsuzawa, K. Kubota, K. Murofushi. (1982) Object and color naming in chimpanzees (Pan troglodytes). Proceedings of the Japan Academy, 58, pp. 118–122
Ai debuted in a Japanese picture book titled "A chimpanzee learned language" written by Dr. Tetsuro Matsuzawa. This fantastic story was appearing in a Japanese textbook and made many children happy, fascinated and inspired. Dr. Matsuzawa concluded in the book: "Ai is now 9 years-old and growing up. Ai would give birth to a baby some day in the future. The baby might learn this, – to a chimpanzee – unique language from her mother. As Ai's descendants consecutively will take over language, it would be amazing when human beings and chimpanzees will be able to understand each other someday."
Books "A chimpanzee learned language"(Japanese version only)
We proved that color perception and classification in a chimpanzee (Ai) was quite similar to that in humans. Ai, who has already learned and can recognize 10 colors by names (red, orange, yellow, green, blue, purple, pink, brown, grey, and black) using the lexigram, she was then asked to name about 200 color chips from the Munsell color charts. Ai and a human examinee similarly classified them.
Matsuzawa T(1985) Colour naming and classification in a chimpanzee (Pan troglodytes). Journal of Human Evolution, Volume 14, Issue 3, Pages 283–291
Ai learned 1-6 Arabic numerals.
Ai broke a myth that only human beings can recognize Arabic numerals. We reported that Ai had learned to use 1-6 Arabic numerals to represent the number of items.
Matsuzawa T(1985) Use of numbers by a chimpanzee. Nature, 315, 57– 59
Dr. Matsuzawa first visited Bossou, Guinea, West Africa where one of his KUPRI colleagues, Dr. Yukimaru Sugiyama, had launched a long running field study of wild chimpanzees in 1976.
Ai learned 26 letters of the alphabet.
Ai learned to distinguish perfectly every letter of the alphabet in a matching-to-sample task with 26 letters as choice alternatives. She also readily learned to use letters as names of individual humans and chimpanzees. Additionally, we tested her visual acuity by using letters of various sizes. The test revealed that her acuity was about 1.5, comparable to that in normal humans.
Matsuzawa T(1990) Form perception and visual acuity in a chimpanzee. Folia Primatologica, 55, 24–32
An academic Japanese-language book titled "Chimpanzee kara mita sekai" about the project was published.
Book "Chimpanzee kara mita sekai"(Japanese version only)
We built a brand-new facility named "Ape Research Annex" at KUPRI.
We have constructed 8 meter-high climbing frames in our outdoor compound, planted trees, and introduced a small stream.
We started to plan that Ai will become a mother and Akira will become a father to their child by performing artificial insemination with a financial support by a grant-in-aid from the Ministry of Education, Science and Culture, Japan.
By adding each tower to the former structure that was built in 1995, we have built a 15m high climbing structure at KUPRI. It was, called "triple tower", made up of three towers and joined together in an equilateral triangle.
Ai gave birth to a stillbirth baby who was to be called Atomu.
Ai became a mother.
Three female chimpanzees living at KUPRI became mothers. Ai gave birth to Ayumu, Chloe gave birth to Cleo, and Pan gave birth to Pal. Ayumu and Pal were born using artificial insemination. Cleo was born by natural breeding.
Ai showed that chimpanzees can remember number sequences, the same as (or even more than) preschool children.
We trained Ai to memorize the location of numbers as they flashed onto a computer screen. The numbers would be quickly covered with white squares, and Ai could then touch those squares in order of the numbers concealed beneath them.
Kawai N, Matsuzawa T(2000) Numerical memory span in a chimpanzee. Nature, Volume: 403, Issue: 6765, Pages: 39–40
We published the first English book titled "Primate origins of human cognition and behavior".
In this book, we guided readers into a fascinating field of comparative cognitive science.
Book"Primate origins of human cognition and behavior"
In the English book titled "Cognitive Development in Chimpanzees", we introduced multiple findings based on observations of chimpanzee infants who were raised by their own mothers. The book was one of the fruits of research based on a triadic relationship among a chimpanzee mother, a chimpanzee infant, and a human researcher.
Book "Cognitive development in chimpanzees"
In Current Biology, we reported that young chimpanzees can recall number placement better than human adults can.
Inoue S, Matsuzawa T(2007)Working memory of numerals in chimpanzees. Current Biology, Volume 17, Issue 23, R1004–R1005


Colour naming and classification task
Numerical memory span in a chimpanzee
Use of numbers by a chimpanzee