Jiji Press KYOTO (Jiji Press) — A Japanese research group said Thursday it has found that chimpanzees have the ability to learn the rules of the rock-paper-scissors game.
“The study shows that a chimpanzee has a cognitive capacity roughly equivalent to that of a four-year-old child,” said Tetsuro Matsuzawa, a professor at Kyoto University.
The findings by the group led by Matsuzawa were published online in the primatology journal Primates.
The group edited photographs of chimpanzee hands and displayed one of three pairs—rock-scissors, scissors-paper and paper-rock—on a computer screen.
When a chimpanzee chose the stronger of two options, it was given either an apple or dried grapes and a chime was sounded.
The group trained seven chimpanzees aged between 14 and 38 years, playing the game 144 times a day.
Five of the seven chimpanzees fully mastered the rock-paper-scissors game in about 100 days on average.
The other two chimpanzees demonstrated 70 to 80 percent proficiency.
The researchers conducted a similar study on 38 children aged 35 months through 71 months using photographs of human hands. They found that children can master the rock-paper-scissors game at the age of around 4 years old.