Despite an increasing number of studies demonstrating that young children selectively learn from others, and a few studies of children's selective teaching, the evidence almost exclusively comes from Western cultures, and cross-cultural comparison in this line of work is very rare. In the present research, we investigated Japanese and German children's selective learning and teaching abilities. We found clear cultural differences. Japanese children were better at selectively teaching an ignorant person over a knowledgeable person than at selectively learning from knowledgeable others. By contrast, German children were better at choosing to learn from a knowledgeable rather than from an ignorant person than at selectively teaching ignorant others. The present findings suggest that the development of human learning and teaching, especially the tendency to take into account others' knowledge status, is strongly affected by cultural background.