Fetal brain development in chimpanzees versus humans

chimpanzee, 34–35 weeks) [4], human neonates do have larger brains than chimpanzee neonates [2]. It has been suggested that the extraordinary brain enlargement in humans is due to unique features in the human pattern of brain development during both the prenatal and postnatal periods [1,2]. It has been argued that all primates conform to a 12% ratio of brain mass to body mass from the fetal period to birth [5,6], though a recent study [7] suggested that the brain of a chimpanzee neonate accounts for 10% of its body weight, whereas that of a human neonate, on average, accounts for 12.3%, an increase due Fetal brain development in chimpanzees versus humans