Host: Primate Society of Japan
To make clear the evolutionally background of human language, we focused on the concept of number in chimpanzees. Some previous studies picked up cardinal and ordinal number in non-human primates, but there is no research about the positional notation system in them. The process of learning the notation system contains the rule learning, and human’s language also require the rule learning. Therefore, we conducted the computer-based experiment which enables us to investigate the learning of notation system in chimpanzees. Chimpanzees in Primate Research Institute, Kyoto University, have already learned the order of Arabic numerals from 1to 9, and one of them (Ai) has an experience of participating to the cardinal task and using zero. From the ordinal aspect, we extended their knowledge of numerical order “over 10.” After chimpanzees learning the sequence from 1 to 19, we added “0” to it. From the cardinal aspect, we conducted Dot-to-Dot matching-to-sample task at first, since some chimpanzees have no experience of using dots in computer-based tasks. After them reaching the criteria, the cardinal number task, Dot-to-Number/Number-to-Dot task, was started. We show you the progress of study with some results of our number concepts study.
