О половых различиях на ранних стадиях развития поведения см. Daniel G. Freedman, Human Infancy; A. F. Korner, Neonatal Startles, Smiles, Erections and Reflex Sucks as Related to State, Sex and Individuality, Child Development 40: 1039— 1053 (1969); Jerome Kagan, Change and Continuity in Infancy (Wiley, New York, 1971).
