American kindergarten children lag behind Japanese children in their understanding of mathematics; by fifth grade they are surpassed by both Japanese and Chinese children. Efforts to isolate bases for these differences involved testing children on other achievement and cognitive tasks, interviewing mothers and teachers, and observing children in their classrooms. Cognitive abilities of children in the three countries are similar, but large differences exist in the children's life in school, the attitudes and beliefs of their mothers, and the involvement of both parents and children in schoolwork.