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- Byrne, Brian, et al.
(författare)
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Genetic and environmental influences on aspects of literacy and language in early childhood : Continuity and change from preschool to Grade 2
- 2009
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Ingår i: JOURNAL OF NEUROLINGUISTICS. - : Elsevier BV. - 0911-6044. ; 22:3, s. 219-236
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Tidskriftsartikel (refereegranskat)abstract
- Early literacy and language skills of twin children in the USA, Australia, and Scandinavia were explored in a genetically sensitive design (maximum N = 615 pairs). For this article, we report aspects of preschool and Grade 2 data. In Grade 2, there were strong genetic influences on word reading, reading comprehension, and spelling. Vocabulary was about equally affected by genes and shared environment. Multivariate analyses indicated substantial genetic overlap among the Grade 2 literacy variables. Longitudinal analyses showed that genetic factors evident at the preschool stage continued to affect literacy and vocabulary three years later in Grade 2, but there was also evidence of new genetic factors coming into play over the time interval, at least for literacy. Suggestions are made about the search for underlying biological and cognitive processes, and educational implications are explored.
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| 2. |
- Byrne, Brian, et al.
(författare)
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Genetic and environmental influences on early literacy
- 2006
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Ingår i: Journal of research in reading (Print). - : Wiley. - 0141-0423 .- 1467-9817. ; 29:1, s. 33-49
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Tidskriftsartikel (refereegranskat)abstract
- Prereading and early reading skills of preschool twin children in Australia, Scandinavia and the United States were explored in a genetically sensitive design (max. N = 627 preschool pairs and 422 kindergarten pairs). Analyses indicated a strong genetic influence on preschool phonological awareness, rapid naming and verbal memory. Print awareness, vocabulary and grammar/morphology were subject primarily to shared environment effects. There were significant genetic and shared environment correlations among the preschool traits. Kindergarten reading, phonological awareness and rapid naming were primarily affected by genes, and spelling was equally affected by genes and shared environment. Multivariate analyses revealed genetic and environmental overlap and independence among kindergarten variables. Longitudinal analyses showed genetic continuity as well as change in phonological awareness and rapid naming across the 2 years. Relations among the preschool variables of print awareness, phonological awareness and rapid naming and kindergarten reading were also explored in longitudinal analyses. Educational implications are discussed. © United Kingdom Literacy Association 2006.
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| 4. |
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| 5. |
- Christopher, Micaela E., et al.
(författare)
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Predicting Word Reading and Comprehension With Executive Function and Speed Measures Across Development: A Latent Variable Analysis
- 2012
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Ingår i: Journal of experimental psychology. General. - : American Psychological Association. - 0096-3445 .- 1939-2222. ; 141:3, s. 470-488
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Tidskriftsartikel (refereegranskat)abstract
- The present study explored whether different executive control and speed measures (working memory, inhibition, processing speed, and naming speed) independently predict individual differences in word reading and reading comprehension. Although previous studies suggest these cognitive constructs are important for reading, the authors analyze the constructs simultaneously to test whether each is a unique predictor. Latent variables from 483 participants (ages 8-16 years) were used to portion each cognitive and reading construct into its unique and shared variance. In these models 2 specific issues are addressed: (a) Given that the wide age range may span the theoretical transition from "learning to read" to "reading to learn," the authors first test whether the relation between word reading and reading comprehension is stable across 2 age groups (ages 8-10 and 11-16); and (b) the main theoretical question of interest: whether what is shared and what is separable for word reading and reading comprehension are associated with individual differences in working memory, inhibition, and measures of processing and naming speed. The results indicated that (a) the relation between word reading and reading comprehension is largely invariant across the age groups, and (b) working memory and general processing speed, but not inhibition or the speeded naming of nonalphanumeric stimuli, are unique predictors of both word reading and comprehension, with working memory equally important for both reading abilities and processing speed more important for word reading. These results have implications for understanding why reading comprehension and word reading are highly correlated yet separable.
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| 7. |
- Fujisawa, Keiko K., et al.
(författare)
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A multivariate twin study of early literacy in Japanese kana
- 2013
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Ingår i: Learning and individual differences. - : Elsevier. - 1041-6080 .- 1873-3425. ; 24, s. 160-167
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Tidskriftsartikel (refereegranskat)abstract
- This first Japanese twin study of early literacy development investigated the extent to which genetic and environmental factors influence individual differences in prereading skills in 238 pairs of twins at 42 months of age. Twin pairs were individually tested on measures of phonological awareness, kana letter name/sound knowledge, receptive vocabulary, visual perception, nonword repetition, and digit span. Results obtained from univariate behavioral-genetic analyses yielded little evidence for genetic influences, but substantial shared-environmental influences, for all measures. Phenotypic confirmatory factor analysis suggested three correlated factors: phonological awareness, letter name/sound knowledge, and general prereading skills. Multivariate behavioral genetic analyses confirmed relatively small genetic and substantial shared environmental influences on the factors. The correlations among the three factors were mostly attributable to shared environment. Thus, shared environmental influences play an important role in the early reading development of Japanese children.
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| 8. |
- Olson, Richard, et al.
(författare)
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Genetic and Environmental Influences on Vocabulary and Reading Development
- 2011
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Ingår i: SCIENTIFIC STUDIES OF READING. - : Taylor and Francis. - 1088-8438 .- 1532-799X. ; 15:1, s. 26-46
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Tidskriftsartikel (refereegranskat)abstract
- Genetic and environmental relations between vocabulary and reading skills were explored longitudinally from preschool through Grades 2 and 4. At preschool there were strong shared-environment and weak genetic influences on both vocabulary and print knowledge but substantial differences in their source. Separation of etiology for vocabulary and reading continued for word recognition and decoding through Grade 4, but genetic and environmental correlations between vocabulary and reading comprehension approached unity by Grade 4, when vocabulary and word recognition accounted for all of the genetic and shared environment influences on reading comprehension.
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| 9. |
- Samuelsson, Stefan, 1964-, et al.
(författare)
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Environmental and genetic influences on prereading skills in Australia, Scandinavia, and the United States
- 2005
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Ingår i: Journal of Educational Psychology. - : American Psychological Association (APA). - 0022-0663 .- 1939-2176. ; 97:4, s. 705-722
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Tidskriftsartikel (refereegranskat)abstract
- Individual differences in measures of prereading skills and in questionnaire measures of 4-5-year-old twins' print environments in Australia, Scandinavia, and the United States were explored with a behavioral-genetic design. Modest phenotypic correlations were found between environmental measures and the twins' print knowledge, general verbal ability, and phoneme awareness. Lower print knowledge in Scandinavian twins was related to country differences in preschool print environment. Latent-trait behavioral-genetic analyses indicated very strong shared-environment influences on individual differences in Print Knowledge. Genetic influence was also significant. Several other prereading skills varied in their environmental and genetic influence, including a significant contrast between Phonological Awareness and Print Knowledge. Rapid Naming also revealed very strong genetic influence, as did Verbal Memory. Stronger shared-environment influences were found for Vocabulary and Grammar/Morphology. Genetic and environmental correlations among latent traits for General Verbal Ability, Phonological Awareness, and Print Knowledge were high, but there were also significant independent genetic and environmental contributions to each skill. Practical implications include the need for substantial and sustained instructional support for children hampered by genetic constraints on early literacy development. Copyright 2005 by the American Psychological Association.
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| 10. |
- Samuelsson, Stefan, et al.
(författare)
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Response to early literacy instruction in the United States, Australia, and Scandinavia : A behavioral-genetic analysis
- 2008
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Ingår i: Learning and individual differences. - : Elsevier BV. - 1041-6080 .- 1873-3425. ; 18:3, s. 289-295
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Tidskriftsartikel (refereegranskat)abstract
- Genetic and environmental influences on early reading and spelling at the end of kindergarten and Grade 1 were compared across three twin samples tested in the United States, Australia, and Scandinavia. Proportions of variance due to genetic influences on kindergarten reading were estimated at .84 in Australia, .68 in the U.S., and .33 in Scandinavia. The effects of shared environment on kindergarten reading were estimated at .09 in Australia, .25 in the U.S., and .52 in Scandinavia. A similar pattern of genetic and environmental influences was obtained for kindergarten spelling. One year later when twins in all three samples had received formal literacy instruction for at least one full school year, heritability was similarly high across country, with estimated genetic influences varying between .79 and .83 for reading and between .62 and .79 for spelling. These findings indicate that the pattern of genetic and environmental influences on early reading and spelling development varies according to educational context, with genetic influence increasing as a function of increasing intensity of early instruction. Longitudinal analyses revealed genetic continuity for both reading and spelling between kindergarten and Grade 1 across country. However, a new genetic factor comes into play accounting for independent variance in reading at Grade 1 in the U.S. and Scandinavia, suggesting a change in genetic influences on reading. Implications for response-to-instruction are discussed.
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