Describes growth in the number of studies of behavior development conducted in Japan during the last 20 years and identifies areas of development receiving attention by Japanese researchers. (RH)

The study sought to examine developmental processes of substitution in the pretend play of Down's syndrome children and to clarify the onset mechanism of subskills in decontextualization, which refers to the progress from imitation to substitution and then to invention. Eighteen Japanese children, aged 29-55 months, with Down's syndrome were given…