The author presents a rough chronology of emerging ego functions in human maturation which distinguishes between primitive 'precorticate' adaptations and true ego processes. Evidences from writings by authorities in neuroanatomy and neurophysiology support inferences previously based on direct infant observation. Only mechanisms capable of binding instinctual energies can be accepted as having true ego functions.

The neocortex of the newborn possesses cells of such immaturity as to lead to the conclusion that the neonate is essentially a precorticate organism. As the cortical cells mature, a correlation appears with early signs of ego development, and the emerging ego assumes control over more primitive processes.