85. Emde, R.N., & Hewitt, J.K. (2001). Infancy to early childhood: Genetic and environmental influences on developmental change. Oxford: Oxford University Press.

This is the first published volume resulting from the MacArthur Longitudinal Twin Study, a unique collaboration of developmental scientists and behavioral geneticists. It focuses upon the transition from infancy to early childhood, such as the acquisitions of speech and empathy asa well as new aspects of emotion regulation, temperament, cognition and self-awareness. Among the findings are that development is mutlifaceted with a high degree of phenotypic differentiation between and within the domains of temperament, emotion and cognition; that genetic and environmental influences vary in magnitude and type depending on the behavior; and that genetic factors largely account for continuity, while non-shared environmental factors account for change.