Provides a foundation for future experimental research on the origins in mother-infant interaction of sex differences in the development of a separate sense of self. Suggests that sex differences in the experience of a separate sense of self begin to emerge in early infancy and that mothers engage in different types of contact with sons and…

To test the inversion of intensity interpretation based on negative relations between newborn and pre-school intensity behaviors, 106 normal children were examined at the neonatal and pre-school periods. Interpretations of intensity behaviors at both periods and their longitudinal relations are discussed. (Author/SB)