KYOTO, Japan — Can’t find anyone to play rock-paper-scissors with? Take a trip to your local zoo. You may find a chimpanzee that will not only take you on, but just might beat you.
Scientists studying chimps found that they can learn how to play rock-paper-scissors at about the same level of comprehension and skill as a young human child. The researchers tracked how well the chimps can learn simple circular relationships, and used the simple hand gesture game as a way to test them.
Lead author Jie Gao, of Kyoto University in Japan and Peking University in China, concluded that while chimps may take longer than humans to understand and play the game, once learned, their skill level is about on par with that of a 4-year-old human.
Gao and his team wanted to find out if chimps can grasp complex patterns like humans can. The nonlinear relationships between the three different hand signals were a perfect way to measure this. Learning that paper always beats rock, rock always beats scissors, and scissors always beats paper requires enhanced mental capacity needed to form complex relationship networks, problem-solving, and to add to knowledge about a subject.
The authors were able to teach the chimps the circular pattern at the heart of the game with computer-based touchscreen technology. Once they understood the pairs that fit together, they were shown various pairs at random on the screen and had to pick the correct choice. Five of seven chimps tested were able to complete the training after 307 sessions.
Gao’s team compared the chimps’ performance with that of 38 preschool children, and found that in humans, the older they are, the better they become. The children only needed about five sessions on average to get the hang of the game.
“This suggests that children acquire the ability to learn a circular relationship and to solve a transverse patterning problem around the age of four years,” explains Gao in a media release. “The chimpanzees’ performance during the mixed-pair sessions was similar to that of four-year-old children.”
The full study was published in the January 2018 edition of the journal Primates.