Growth of the human brain and skull slows down at about 2.5 years old

Brain and skull changes in postnatal growth were studied on a sample of 199 children and teenagers from 2 months to 21 years (42% under 3). Four measurements were taken on the para-median sagittal section of MRI brain scans: the glabella–opisthocranion and basion–vertex distances, and the ‘cerebral hemisphere’ and ‘infratentorial’ surfaces. Data were fitted by the cubic-spline method. Results have shown a slowing down for both brain and skull measurements between 2 and 3 years, earlier in boys. The tight relationship in growth timing between brain and skull is of great interest in palaeoanthropology, allowing inferences on brain changes from hominid skulls.