This study investigates whether cultural differences affect childrens’ performances on the Design Copying (DC) and Motor Accuracy-Revised (MAC-R) Tests of the Southern California Sensory Integration Tests. The DC and the MAC-R were administered to 98 children who were born in Japan and lived there at least during the first year of life and to 82 children who were of Japanese descent but who were born in America. Average test scores of the Japanese and Japanese-American children were compared with those of the American children, on whom the tests were standardized. Results of the tests requiring right-hand performance revealed that both groups of Japanese-descent children performed better than the standardization group of American children; the Japan-born children performed the best. We base these findings on the influence that culture has on the development of a child.