in education and child development, little is known
about their genetic and environmental origins in the
early school years. We report results for English (which
includes reading, writing, and speaking), mathematics,
and science as well as general cognitive ability in a large
and representative sample of U.K. twins studied at 7, 9,
and 10 years of age. Although preliminary reports of
some of these data have been published, the purpose of
this monograph is to present new univariate, multivariate,
and longitudinal analyses that systematically examine
genetic and environmental influences for the entire sample
at all ages for all measures for both the low extremes
(disabilities) and the entire sample (abilities).
English, mathematics, and science yielded similarly
high heritabilities and modest shared environmental
influences at 7, 9, and 10 years despite major changes
in content across these years. We draw three conclusions
that go beyond estimating heritability. First, the abnormal
is normal: low performance is the quantitative extreme
of the same genetic and environmental influences
operate throughout the normal distribution. Second, continuity
is genetic and change is environmental: longitudinal
analyses suggest that age–to–age stability is primarily
mediated genetically whereas the environment contributes
to change from age to age. Third, genes are generalists
and environments are specialists: multivariate analyses
indicate that genes largely contribute to similarity
in performance within and between the three domains
and with general cognitive ability whereas the environment
contributes to differences in performance.
These conclusions have far–reaching implications for
education and child development as well as for molecular
genetics and neuroscience.
I. INTRODUCTION 1.
II. METHODS 14.
III. NATURE AND NURTURE 49.
IV. THE ABNORMAL IS NORMAL 60.
V. GENETIC STABILITY, ENVIRONMENTAL CHANGE 67.
VI. GENERALIST GENES, SPECIALIST ENVIRONMENTS 82.
VII. CONCLUSIONS AND IMPLICATIONS 105.
BEYOND NATURE NURTURE.
Richard A. Weinberg 145.
DYNAMIC DEVELOPMENT AND DYNAMIC EDUCATION.
Jennifer M. Thomson and Kurt W. Fischer 150.
STATEMENT OF EDITORIAL POLICY 159
Claire M. A. Haworth is a Ph.D. Student at the Social, Genetic and Developmental Psychiatry Centre at the Institute of Psychiatry. In 2004 she graduated from Oxford University with a B.A. in Experimental Psychology, and in 2006 was awarded an M.Sc. in Social, Genetic and Developmental Psychiatry. Her research interests include the use of quantitative and molecular genetic techniques to unravel the genetic and environmental influences on quantitative traits. Her traits of interest include academic and cognitive abilities and disabilities. Claire is particularly interested in science performance in schools, and how science is related to other cognitive and academic abilities.
Philip S. Dale is Professor and Chair of Speech and Hearing Sciences at the University of New Mexico. He received his Ph.D. in communication sciences from the University of Michigan in 1968. His current research interests center on issues of assessment, sources, and consequences of individual differences in early language development and the emergence of literacy, cross–linguistic and cross–cultural comparisons, and outcomes of parent– and classroom–based intervention for developmental disabilities.
Robert Plomin is MRC Research Professor and Deputy Director of the SGDP Centre at the Institute of Psychiatry in London. He received his Ph.D. in psychology from the University of Texas at Austin in 1974. He was then at the Institute for Behavioral Genetics in Boulder, Colorado (1974 1986) and at Pennsylvania State University (1986 1994) until he moved to London and launched the Twins Early Development Study (TEDS). His current research combines quantitative genetic and molecular genetic analyses of learning abilities and disabilities in childhood. Richard A. Weinberg (Ph.D., 1968, University of Minnesota) is Distinguished University Teaching Professor of Child Psychology at the Institute of Child Development, University of Minnesota, where he is also Director of the Center for Early Education and Development and Adjunct Professor of Psychology and Educational Psychology. He has collaborated with Sandra W. Scarr for over 35 years pursuing research in developmental behavior genetics.
Jennifer Thomson is an Assistant Professor at the Harvard Graduate School of Education, having moved from the Centre for Neuroscience in Education, University of Cambridge, U.K. Her current research focuses upon the links between language and literacy development, specifically, the role of linguistic rhythm sensitivity in dyslexia. She is also particularly interested in how neuroscience can be usefully applied to the fields of learning and remediation.
Kurt Fischer analyzes cognition, emotion, and learning and their relation to biological development and educational assessment. In his research, he has discovered a scale that seems to assess learning and development in all domains, even when the skills created in each domain are independent. As head of the Mind, Brain, and Education program and Charles Bigelow Professor of Education and Human Development at the Harvard Graduate School of Education, he leads an international movement to connect biology and cognitive science to education. His most recent book is Mind, Brain, and Education in Reading Disorders (Cambridge University Press, 2006). He is founding president of the International Mind, Brain, and Education Society and founding editor of the journal Mind, Brain, and Education (Blackwell).