Summary: Study reveals chimpanzees are able to learn the circular relationship between hand patterns in the game ‘rock-paper-scissors’ as well as a four year old child.
New study shows that chimps’ ability to learn simple circular relationships is on a par with that of four-year-old children.
Chimpanzees of all ages and all sexes can learn the simple circular relationship between the three different hand signals used in the well-known game rock-paper-scissors. Even though it might take them longer, they are indeed able to learn the game as well as a young child. Jie Gao of Kyoto University in Japan and Peking University in China is lead author of a study in the journal Primates, which is the official journal of the Japan Monkey Centre, and is published by Springer. The research compares the ability of chimpanzees and children to learn the rock-paper-scissors game.
Gao’s research team wanted to find out whether chimpanzees (Pan troglodytes) can grasp extended patterns. They used the rock-paper-scissors game, a popular children’s game in which the hand signal for “paper” always beats “rock”, while “rock” trumps “scissors”, and “scissors” defeats “paper”. The relationship between the signals are non-linear and must be understood within the context of how the pairs are grouped. Learning such transverse patterns requires enhanced mental capacity and it is useful when forming complex relationship networks, solving problems, or updating what you already know about a subject.
Seven chimpanzees of different ages and sexes living in the Primate Research Institute at Kyoto University were part of the experiment. They sat in a booth housing a computer-based touchscreen and were trained to choose the stronger of two options (based on the rules of the game) they saw on screen. They first learnt the paper-rock sequence, then the rock-scissors one and finally the scissors-paper combination. Once they knew how the pairs fitted together, all the different pairs were randomly presented to them on screen. Five of the seven chimpanzees completed the training after an average of 307 sessions.
The findings show that chimpanzees can learn the circular pattern at the heart of the game. However, it took them significantly longer to learn the third scissors-paper pair than it did to grasp the others, which indicates that they had difficulty finalizing the circular nature of the pattern.
The research team then also taught the game to 38 preschool children to compare the learning process of chimpanzees with that of humans aged three to six. The children had little difficulty grasping the game, and on average did so within five sessions. Their performance was, however, subject to age. The older the children were, the more accurate they became when all three pairs were randomly presented to them. Participants older than 50 months (about four years) played the game with more skill rather than luck.
“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,” says Gao. “The chimpanzees’ performance during the mixed-pair sessions was similar to that of four-year-old children,” adds Gao, who hopes the findings will inspire future studies into how age and sex influence the ability of members of various species to learn circular relationships.
Image Source: NeuroscienceNews.com image is credited to Primate Research Institute, Kyoto University.
Original Research: Full open access research for “Learning the rules of the rock–paper–scissors game: chimpanzees versus children” by Jie Gao, Yanjie Su, Masaki Tomonaga, and Tetsuro Matsuzawa in Primates. Published online August 10 2017 doi:10.1007/s10329-017-0620-0
Learning the rules of the rock–paper–scissors game: chimpanzees versus children
The present study aimed to investigate whether chimpanzees (Pan troglodytes) could learn a transverse pattern by being trained in the rules of the rock–paper–scissors game in which “paper” beats “rock,” “rock” beats “scissors,” and “scissors” beats “paper.” Additionally, this study compared the learning processes between chimpanzees and children. Seven chimpanzees were tested using a computer-controlled task. They were trained to choose the stronger of two options according to the game rules. The chimpanzees first engaged in the paper–rock sessions until they reached the learning criterion. Subsequently, they engaged in the rock–scissors and scissors–paper sessions, before progressing to sessions with all three pairs mixed. Five of the seven chimpanzees completed training after a mean of 307 sessions, which indicates that they learned the circular pattern. The chimpanzees required more scissors–paper sessions (14.29 ± 6.89), the third learnt pair, than paper–rock (1.71 ± 0.18) and rock–scissors (3.14 ± 0.70) sessions, suggesting they had difficulty finalizing the circularity. The chimpanzees then received generalization tests using new stimuli, which they learned quickly. A similar procedure was performed with children (35–71 months, n = 38) who needed the same number of trials for all three pairs during single-paired sessions. Their accuracy during the mixed-pair sessions improved with age and was better than chance from 50 months of age, which indicates that the ability to solve the transverse patterning problem might develop at around 4 years of age. The present findings show that chimpanzees were able to learn the task but had difficulties with circularity, whereas children learned the task more easily and developed the relevant ability at approximately 4 years of age. Furthermore, the chimpanzees’ performance during the mixed-pair sessions was similar to that of 4-year-old children during the corresponding stage of training.
“Learning the rules of the rock–paper–scissors game: chimpanzees versus children” by Jie Gao, Yanjie Su, Masaki Tomonaga, and Tetsuro Matsuzawa in Primates. Published online August 10 2017 doi:10.1007/s10329-017-0620-0