Memorial Website for ‘Genius’ Chimpanzee Launched in Japan

Jiji Press

10:42 JST, March 5, 2026

INUYAMA, Aichi (Jiji Press) — Kyoto University’s Center for the Evolutionary Origins of Human Behavior has launched a memorial website for Ai, a chimpanzee known as a “genius” for her cognitive abilities, after she died at the age of 49.

“Ai was a research partner who taught me many things about the minds and existence of chimpanzees, as well as about humans,” said Ikuma Adachi, 47, associate professor at the university, who worked with the chimpanzee for 18 years.

Born in Africa, Ai arrived at the center in Inuyama, Aichi Prefecture in 1977 at the age of one.

Adachi said she was “curious and adapted well to a human-made environment.”

The “Ai Project” started in 1978 to investigate chimpanzees’ thinking and language abilities. In 1985, a paper on Ai was published in the British scientific journal Nature. In 1989, she “escaped” from the center using a key found nearby, drawing public attention.

According to Adachi, Ai was not the only chimpanzee with special cognitive abilities. While some other chimpanzees showed similar test results, Ai’s persistent efforts on various tasks helped establish a method for examining chimpanzees’ cognitive functions, making her contributions significant to research.

As she aged, Ai’s interest shifted to interactions with researchers and breeding staff rather than experiments and meals. She had chronic kidney disease and had been eating less since late last year. On Jan. 9, she died, surrounded by many people. A handmade altar was set up in Adachi’s laboratory.

In addition to memorial messages, the website also collects donations to improve the breeding environment for 10 chimpanzees, including Ai’s son, Ayumu.

“We will continue to conduct research to deepen understanding of chimpanzees’ minds and human nature,” Adachi said.