Nature and Nurture During Middle Childhood
About this book
What are the origins of individual differences? Virtually no one studying human development today sees the nature/nurture question as an either-or one. However, very few developmental researchers as yet appreciate the extent to which it is now possible to map genetic influences in a range of domains from cognitive functioning to temperament all through the childhood years. (For example, although there is substantial genetic continuity for measures of general cognitive ability from infancy to early childhood, new genetic influences emerge to affect IQ in middle childhood, when specific cognitive abilities also begin to differentiate.) Even fewer developmental researchers appreciate the startling way in which expressions of the child's genetic endowment appear to affect what we have been accustomed to thinking of as stable environmental forces. In this book, three leading international authorities on behavior genetics and their collaborators present the most recent findings from the landmark Colorado Adoption Project. This first large-scale, longitudinal adoption study, launched in 1975, tracked the children, biological and adoptive parents, and home environments of 245 adoptive families and 245 matched non-adoptive families. Its design facilitated analyses of genetic and environmental influences on development of unparalleled scope and diversity - via both parent-offspring and sibling comparisons, and longitudinal and multivariate assessments. Following two introductory chapters, the authors focus successively on general and specific cognitive abilities, school achievement, language disorders, personality, stress, body size and obesity, motoric development, sex differences, competence, and family relationships. Before summarizing and concluding, they then turn to issues like the meaning of "shared" environment, the correlations and interactions between "nature" and "nurture," and the practical implications of the findings for adoption policy. Nature and Nurture