Kagan J
Pediatrics. 1982 Sep;70(3):474-83.
Recent research on the infant and young child suggests that the maturation of cognitive abilities and biologicaly based temperamental dispositions plays an important role in early psychological development. The enhancement of the cognitive competence of retrieval memory displayed during the end of the first year is a prerequisite for the universal fears of infancy, and the capacities for empathy and inference appear to be necessary for the development of standards on aggression. The temperamental disposition to display inhibition and distress to the unfamiliar appears to be a stable and significant characteristic of children in the second year of life.
