Early spontaneous categorization in primate infants-chimpanzees, humans, and Japanese macaques-with the familiarization-novelty preference task

Abstract

In this chapter, I introduce a series of comparative studies for categorization in infancy of Japanese monkeys (Macaca fuscata), chimpanzees (Pan troglodytes), and humans (Homo sapiens). Categorization is the cognitive activity of sorting objects (or events), that is, grouping objects possessing similar attributes and distinguishing those objects from others possessing dissimilar attributes. This is one of the most important activities for processing objects in the world to flexibly adapt to one's environment.How infant monkeys, infant chimpanzees, and human infants categorize objects was compared using similar experimental methods. Also, the differences and the similarities found between their early categorization were explored. In a series of experiments, the familiarization-novelty preference task, which is generally used for human infant study, was applied for all the species. None of the species received any special training involving reinforcements during the experiments. By this means, I attempted to examine spontaneous categorization by primate infants.