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Using Cholesky Decomposition to Explore Individual Differences in Longitudinal Relations between Reading Skills
Published on: September 17, 2019
Colorado longitudinal twin study of reading disability
Sally J Wadsworth1, John C DeFries, Richard K Olson
1Institute for Behavioral Genetics, University of Colorado, 447 UCB, Boulder, CO 80309, USA. Sally.Wadsworth@Colorado.edu
Annals of Dyslexia
|December 7, 2007
Summary
This study of twins with reading disabilities found that cognitive and reading performance are highly stable over time. Genetic factors significantly influence reading difficulties, with the same genetic influences present at both assessment points.
Area of Science:
- Behavioral Genetics
- Developmental Psychology
- Neuroscience
Background:
- Reading disability is a complex condition with significant implications for academic and personal development.
- Understanding the stability and genetic underpinnings of reading difficulties is crucial for early intervention and support.
- Longitudinal twin studies provide a powerful design to disentangle genetic and environmental influences on developmental trajectories.
Purpose of the Study:
- Introduce the Colorado Longitudinal Twin Study of Reading Disability (CLTSRD), a novel cohort specifically selected for reading difficulties.
- Assess the stability of reading performance and cognitive abilities in twins with and without a history of reading difficulties over a 5- to 6-year interval.
- Conduct preliminary behavior genetic analyses to explore the role of genetic and environmental factors in the stability of reading performance.
Main Methods:
- Longitudinal assessment of 124 twins with reading difficulties and 154 control twins over a 5- to 6-year period.
- Administration of cognitive and reading performance tests at two time points.
- Behavior genetic analyses, including estimation of genetic and phenotypic correlations, to examine stability and shared influences.
Main Results:
- Cognitive and reading performance demonstrated high stability across the 5- to 6-year assessment interval for both groups.
- Twins with reading difficulties exhibited substantial and persistent deficits compared to control subjects.
- A composite measure of reading showed the highest stability (correlation of 0.80).
- Preliminary analyses indicated that shared genetic influences accounted for a significant portion of the phenotypic correlations (86% and 49%) for twin pairs with and without reading difficulties, respectively.
- Genetic correlations reaching unity suggest that the same genetic factors influence reading performance at both time points.
Conclusions:
- Reading performance and associated cognitive abilities are highly stable in individuals with a history of reading difficulties.
- Genetic factors play a substantial role in the stability of reading difficulties, with consistent genetic influences over time.
- The CLTSRD provides a valuable resource for future research into the etiology and developmental course of reading disabilities.
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