AbstractThis study investigated two hypotheses: (a) Japanese mother‐toddler dyads will work together more interdependently than American mother‐toddler dyads; (b) American toddlers will act more autonomously than Japanese toddlers. The hypotheses were investigated using videotapes of 10‐minute shape‐fitting interactions of 12 Caucasian American and 12 Japanese national mothers visiting the United States and their 24‐ to 31‐month‐olds (matched by mean age, gender and birth order). A significant MANOVA and subsequent stepdown analyses revealed: (a) that Japanese mothers more frequently assisted their toddlers in fitting a shape before the toddlers had tried to fit the shape on their own (interdependence); (b) that American toddlers did not attempt to fit more shapes on their own (autonomy); and (c) that more American toddlers left the task than did Japanese toddlers (autonomy). The results indicate greater interdependent task‐engagement among Japanese mother‐toddler dyads. Greater autonomy on the part of American dyads was evident not in how they did the task, but rather in toddlers choosing to leave the assigned task. Discussion focuses on the implications of these nationality differences for understanding possible differences in ea