The purpose of this study was to compare performances by Japanese and American children on the Matching Familiar Figures Test, the primary measure of cognitive tempo. Data on more than 3400 Japanese and American children (approximately half male, half female) were used. Factorial analyses of variance revealed significant age x nationality interaction for both errors and latency. Japanese children made fewer errors at a younger age than did their American counterparts, and continued to do so until their level of accuracy approached that of 11- and 12-year-old American children. The interaction for errors indicates a decreasing difference in accuracy as age increases. The age x nationality interaction for latency showed an increase for Japanese children towards a stabilized level, while the latency for American children continued to increase, eventually becoming slower than for the Japanese children. Developmental trends for both errors and latency in both groups of children are highly similar. There appears to be a typical "developmental shift" present, where these identical patterns are present; yet in Japanese children they occur from one to two years earlier than in American children. These results may be related to environmental and cultural differences such as the instruction Japanese children receive in the traditional symbolic character language, the traditional Eastern emphasis on patience, and other educational and cultural influences. (Author/BF)