Ai, a chimpanzee whose remarkable cognitive abilities helped transform scientific understanding of primate intelligence, has died in Japan at the age of 49, researchers said.
Ai — whose name means “love” in Japanese — died on Friday from multiple organ failure and age-related ailments, according to a statement from the Kyoto University Center for the Evolutionary Origins of Human Behavior.
Over decades of research, Ai became internationally known for her ability to recognize more than 100 Chinese characters, the English alphabet, Arabic numerals from zero to nine, and 11 different colours. Her participation in studies on perception, learning and memory significantly advanced scientific knowledge of primate cognition.
Primatologist Tetsuro Matsuzawa previously described Ai’s skills through a series of experiments. In one study, she correctly matched the Chinese character for “pink” with a pink square on a computer screen, distinguishing it from a purple alternative. In another, she selected shapes on a screen — a rectangle, a circle and a dot — to construct a “virtual apple” after being shown the fruit.
Ai’s exceptional abilities made her the focus of numerous academic papers and media features, including research published in the journal Nature. Her achievements earned her the nickname “genius” in popular media.
Originally from West Africa, Ai arrived at Kyoto University in 1977. In 2000, she gave birth to a son, Ayumu, whose advanced cognitive abilities later became central to studies examining how knowledge may be transferred between chimpanzee parents and offspring, according to Japan’s Kyodo News.
Researchers said Ai’s work helped establish a lasting experimental framework for understanding the chimpanzee mind and offered important insights into the evolution of human cognition.
“Ai was highly curious and actively participated in these studies,” the Center said, “revealing various aspects of the chimpanzee mind for the first time.”