Societal perceptions and lived experience: Infant feeding practices in premodern Japan.

The age at the end of weaning became younger after the transition of societal perception toward subadults, and this younger weaning age is inconsistent with written recommendations for the duration of weaning in premodern Japan. It is possible that an increased need for inheritors under the inheritance-based family system led to earlier weaning and shorter inter-birth intervals, but authorities recommended an ideal practice of a longer breastfeeding period.