ABSTRACT
This chapter aims to answer the question: At what age would human infants be weaned if the process were based only on physiological considerations; When would a quadrupling of birth weight typically occur in modern human populations. It evaluates two widespread pediatric "rules of thumb" for determining appropriate weaning age based on biological parameters: tripling of birth weight and equivalence to length of gestation. The chapter also attempts to establish the biological "hominid blueprint" for weaning in an attempt to illuminate the mismatch between evolutionary heritage as primates and pediatric advice and practice in the United States. It examines the comparative primate data with reference to the relationship between natural Age at weaning and tripling or quadrupling of birth weight, attainment of one-third adult weight, adult female body weight, length of gestation, and age at eruption of the first permanent molar. The term weaning refers to time when the infant is no longer allowed to nurse from its mother's breast.
