Book contents
- Frontmatter
- Contents
- Preface
- Acknowledgments
- 1 Introduction
- 2 Individual differences and group differences
- 3 Quantitative genetics as the basis for a general theory of individual differences
- 4 The Colorado Adoption Project
- 5 Transitions and changes: description and prediction
- 6 Transitions and changes: genetic and environmental etiologies
- 7 Introduction to model fitting
- 8 Fitting sibling and parent–offspring models in the Colorado Adoption Project
- 9 Interactions
- 10 Genotype–environment correlation
- 11 Genetics and measures of the family environment: the nature of nurture
- 12 Conclusions
- References
- Author index
- Subject index
6 - Transitions and changes: genetic and environmental etiologies
Published online by Cambridge University Press: 15 October 2009
- Frontmatter
- Contents
- Preface
- Acknowledgments
- 1 Introduction
- 2 Individual differences and group differences
- 3 Quantitative genetics as the basis for a general theory of individual differences
- 4 The Colorado Adoption Project
- 5 Transitions and changes: description and prediction
- 6 Transitions and changes: genetic and environmental etiologies
- 7 Introduction to model fitting
- 8 Fitting sibling and parent–offspring models in the Colorado Adoption Project
- 9 Interactions
- 10 Genotype–environment correlation
- 11 Genetics and measures of the family environment: the nature of nurture
- 12 Conclusions
- References
- Author index
- Subject index
Summary
It must be borne in mind that the divergence of development, when it occurs, need not be ascribed to the effect of different nurtures, but it is quite possible that it may be due to the appearance of qualities inherited at birth, though dormant.
Francis Galton (1875)In addition to the descriptive and predictive changes discussed in the preceding chapter, developmental change can be seen in terms of etiology – changes in genetic as well as environmental influences. Changes in environmental influences can be explored without behavioral genetics; for example, the effects of prematurity on individual differences in social and mental development tend to diminish during infancy (Kopp, 1983). Behavioral genetics, however, provides a particularly powerful and general approach to the study of developmental changes in etiologies of individual differences.
From a behavioral genetics perspective, three kinds of etiological change can be considered; these mirror the phenotypic changes described in Chapter 5. The most basic phenotypic change that can occur is a change in variance, although changes in the magnitude of phenotypic variance are difficult to interpret because measures are not comparable across ages. The analogous genetic concept – change in heritability – is easier to interpret because it refers to a proportion of phenotypic variance due to genetic differences among individuals rather than to the absolute magnitude of variance.
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- Chapter
- Information
- Nature and Nurture during Infancy and Early Childhood , pp. 111 - 156Publisher: Cambridge University PressPrint publication year: 1988