共查询到20条相似文献，搜索用时 31 毫秒
1.
Erik G. Willcutt Rebecca S. Betjemann Sally J. Wadsworth Stefan Samuelsson Robin Corley John C. DeFries Brian Byrne Bruce F. Pennington Richard K. Olson 《Reading and writing》2007,20(1-2):103-125
Numerous studies have examined the etiology of the association between reading difficulties and attention-deficit hyperactivity
disorder (ADHD) in school-age children, but little is known about the relation between prereading skills and ADHD behaviors
prior to the beginning of formal reading instruction. A population-based sample of 809 pairs of preschool twins completed
an extensive battery of prereading measures, and the parent of each twin completed an ADHD rating scale. Phenotypic analyses
revealed small but significant correlations between DSM-IV inattention ratings and six prereading composite measures, whereas
hyperactivity–impulsivity symptoms were not independently associated with any of the prereading scores. Multivariate twin
analyses indicated that virtually all of the phenotypic correlation between inattention and prereading performance is attributable
to common genetic influences, consistent with results obtained in studies of older twins. Although additional research is
needed to test alternative causal models in children younger than five years old, these results are most consistent with the
hypothesis that reading difficulties and inattention symptoms are attributable to common genetic influences. 相似文献
2.
In order to compare the pattern of gender differences for cognitive measures in opposite-sex twin pairs to that in independent
samples of twins from same-sex pairs, psychometric test data were obtained from four research-identified samples of children:
(1) 96 pairs of opposite-sex fraternal twins in which at least one member of each pair is reading disabled; (2) 62 pairs of
opposite-sex fraternal twins with no history of reading problems; (3) 167 males and 155 females from same-sex identical and
same-sex fraternal twin pairs in which at least one member of each pair is reading disabled; and (4) a comparison sample of
126 males and 132 females from same-sex twin pairs with no history of reading problems. Results of multivariate analyses indicate
that gender differences for cognitive measures are similar in twin pairs with and without reading disabilities. Moreover,
a highly similar pattern of gender differences occurs for opposite-sex twin pairs who shared both prenatal and early postnatal
influences and for independent samples of children from different families. 相似文献
3.
Rebecca S. Betjemann Erik G. Willcutt Richard K. Olson Janice M. Keenan John C. DeFries Sally J. Wadsworth 《Reading and writing》2008,21(5):539-558
Longitudinal twin data were analyzed to investigate the etiology of the stability of genetic and environmental influences
on word reading and reading comprehension, as well as the stability of those influences on their relationship. Participating
twin pairs were initially tested at a mean age of 10.3 years, and retested approximately five years later. Both word reading
and comprehension were found to be highly stable, and genetic influences were primarily responsible for that stability. In
contrast to studies with younger participants, no unique genetic influences were observed at follow-up testing in this older
sample. High genetic correlations were obtained between word reading and reading comprehension at both ages, indicating common
genetic influences. However, significant genetic influence on comprehension was also observed, independent of that on word
reading. Although the phenotypic relation between the two measures appeared to decline across time, the genetic etiology of
this relation was highly stable. 相似文献
4.
In order to assess familial resemblance for measures of reading performance, data from 314 pairs of twins in which at least one member of each pair is reading-disabled [142 monozygotic (MZ) and 172 dizygotic (DZ) twin pairs], 273 matched control pairs (131 MZ and 142 DZ pairs), and their parents were subjected to both correlation and regression analyses. Results indicate that parent-offspring resemblance in families of reading-disabled probands does not differ substantially from that in families of controls. In general, the correlations and regressions for MZ twin pairs are greater than those for DZ twins; thus, individual differences in reading performance are due at least in part to heritable influences. As expected, regression coefficients are consistently larger than correlation coefficients for both parent-offspring and proband-cotwin comparisons in the reading-disabled sample, illustrating that regression analyses are more appropriate than correlations for assessing familial resemblance in selected samples. 相似文献
5.
Astrom RL Wadsworth SJ Olson RK Willcutt EG Defries JC 《Learning and individual differences》2012,22(3):365-369
Reading performance data from 254 pairs of identical (MZ) and 420 pairs of fraternal (DZ) twins, 8.0 to 20.0 years of age, were subjected to multiple regression analyses. An extension of the DeFries-Fulker (DF) analysis (DeFries & Fulker, 1985, 1988) that facilitated inclusion of data from 303 of their nontwin siblings was employed. In addition to providing estimates of heritability, this analysis yields a test of the difference between shared environmental influences for twins versus siblings (Astrom et al., 2011). Results suggest that proband reading deficits are due substantially to genetic factors (.67 ± .07, p < .001), and that shared environmental influences are significantly higher for members of twin pairs than for those of twins and their nontwin siblings (viz., .25 versus .17, p = .02). 相似文献
6.
To test the hypothesis that the genetic etiology of reading disability differs as a function of IQ, composite reading performance data from 223 pairs of identical twins and 169 pairs of same-gender fraternal twins in which at least one member of each pair was classified with reading disability were subjected to multiple regression analysis (DeFries & Fulker, 1985, 1988). In the total sample, heritability of the group deficit in reading performance (h(g)2) was .58 (+/- .08). However, when the basic regression model was fitted separately to data from twin pairs with average Wechsler (1974, 1981) full scale IQ scores below 100 or 100 and above, resulting estimates of h(g)2 were .43 and .72, respectively, a significant difference (p < or = .03, one-tailed). The results of fitting extended regression models to reading performance and continuous IQ data provide evidence that the genetic etiology of reading disability differs as a linear function of IQ (p < or = .007, one-tailed). These results suggest that IQ is relevant for the diagnosis of reading disability and that environmental influences may be more salient as a cause of reading difficulties in children with lower IQ scores. 相似文献
7.
Micaela E. Christopher Jacqueline Hulslander Brian Byrne Stefan Samuelsson Janice M. Keenan Bruce Pennington 《Scientific Studies of Reading》2013,17(5):350-368
We explored the etiology of individual differences in reading development from post-kindergarten to post–4th grade by analyzing data from 487 twin pairs tested in Colorado. Data from three reading measures and one spelling measure were fit to biometric latent growth curve models, allowing us to extend previous behavioral genetic studies of the etiology of early reading development at specific time points. We found primarily genetic influences on individual differences at post–1st grade for all measures. Genetic influences on variance in growth rates were also found, with evidence of small, nonsignificant, shared environmental influences for two measures. We discuss our results, including their implications for educational policy. 相似文献
8.
Previous twin studies have provided evidence for genetic influences on reading disability (RD) or normal reading ability. The existence of subtypes of RD — each with its characteristic cognitive profile — has been suggested. Whether the etiology of the particular subtypes is genetic is uncertain. The present study examined within-pair comparisons of cognitive profiles (with respect to composites of general reading, symbol processing speed and sequential memory) in RD and control twins. Twin profile analysis were applied to these cognitive composites on 120 pairs of RD and control twins. Results showed a greater monozygotic (MZ) than dizygotic (DZ) resemblance in profiles indicating that individual differences in the patterning of cognitive abilities related to reading are genetically influenced. 相似文献
9.
Richard K. Olson Jacqueline Hulslander Micaela Christopher Janice M. Keenan Sally J. Wadsworth Erik G. Willcutt Bruce F. Pennington John C. DeFries 《Annals of dyslexia》2013,63(1):25-43
Identical and fraternal twins (N?=?540, age 8 to 18 years) were tested on three different measures of writing (Woodcock-Johnson III Tests of Achievement—Writing Samples and Writing Fluency; Handwriting Copy from the Group Diagnostic Reading and Aptitude Achievement Tests), three different language skills (phonological awareness, rapid naming, and vocabulary), and three different reading skills (word recognition, spelling, and reading comprehension). Substantial genetic influence was found on two of the writing measures, writing samples and handwriting copy, and all of the language and reading measures. Shared environment influences were generally not significant, except for Vocabulary. Non-shared environment estimates, including measurement error, were significant for all variables. Genetic influences among the writing measures were significantly correlated (highest between the speeded measures writing fluency and handwriting copy), but there were also significant independent genetic influences between copy and samples and between fluency and samples. Genetic influences on writing were significantly correlated with genetic influences on all of the language and reading skills, but significant independent genetic influences were also found for copy and samples, whose genetic correlations were significantly less than 1.0 with the reading and language skills. The genetic correlations varied significantly in strength depending on the overlap between the writing, language, and reading task demands. We discuss implications of our results for education, limitations of the study, and new directions for research on writing and its relations to language and reading. 相似文献
10.
Chayna J. Davis Valerie S. Knopik Richard K. Olson Sally J. Wadsworth John C. DeFries 《Annals of dyslexia》2001,51(1):231-247
The present study assesses the genetic and environmental etiologies of reading, rapid naming (RN), and their covariation by
fitting multivariate structural equation models to data from 587 twin pairs in which at least one member of the pair exhibited
reading difficulties (low-range) and from 360 control (normal-range) twin pairs who were tested in the Colorado Learning Disabilities
Research Center. Results from a bivariate phenotypic analysis with two hypothesized latent factors, READ and RN, indicated
that the correlation between reading and rapid naming performance for the low-range sample was significantly higher than that
of the normal-range sample. When this model was partitioned to include estimates of genetic, shared environmental, and nonshared
environmental influences, resulting heritability estimates did not differ significantly for the low-range and normal-range
samples for either READ or RN. However, similar to the phenotypic correlation, the genetic correlation between the READ and
RN latent factors could not be equated for the two groups. Thus, the etiology of the relationship between reading performance
and rapid naming may differ for children with reading difficulties and normally-achieving readers. Moreover, these results
support previous findings that the best predictors of reading skills may differ for samples of children with normal reading
levels and those with reading difficulties. 相似文献
11.
Stefan Samuelsson Richard Olson Sally Wadsworth Robin Corley John C. DeFries Erik Willcutt Jacqueline Hulslander Brian Byrne 《Reading and writing》2007,20(1-2):51-75
Genetic and environmental influences on prereading skills in preschool and on early reading and spelling development at the
end of kindergarten were compared among samples of identical and fraternal twins from the U.S. (Colorado), Australia, and
Scandinavia. Mean comparisons revealed significantly lower preschool print knowledge in Scandinavia, consistent with the relatively
lower amount of shared book reading and letter-based activities with parents, and lack of emphasis on print knowledge in Scandinavian
preschools. The patterns of correlations between all preschool environment measures and prereading skills within the samples
were remarkably similar, as were the patterns of genetic, shared environment, and non-shared environment estimates: in all
samples, genetic influence was substantial and shared environment influence was relatively weak for phonological awareness,
rapid naming, and verbal memory; genetic influence was weak, and shared environment influence was relatively strong for vocabulary
and print knowledge. In contrast, for reading and spelling assessed at the end of kindergarten in the Australian and U.S.
samples, there was some preliminary evidence for country differences in the magnitude of genetic and environmental influences.
We argue that the apparently higher genetic and lower shared environment influence in the Australian sample was related to
a greater emphasis on formal reading instruction, resulting in more advanced reading and spelling skills at the end of kindergarten,
and thus there was greater opportunity to observe genetic influences on response to systematic reading instruction among the
Australian twins. 相似文献
12.
The genetic and environmental origins of learning abilities and disabilities in the early school years 总被引：3，自引：0，他引：3
Kovas Y Haworth CM Dale PS Plomin R 《Monographs of the Society for Research in Child Development》2007,72(3):vii, 1-vii144
Despite the importance of learning abilities and disabilities 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 that 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. 相似文献
13.
Olson RK 《Annals of dyslexia》2006,56(2):205-238
This article presents an overview of some methods and results from our continuing studies of genetic and environmental influences
on dyslexia, and on individual differences across the normal range that have been conducted over the past 25 years in the
Colorado Learning Disabilities Research Center (CLDRC) and in related projects. CLDRC investigators compare the similarities
of identical twin pairs who share all their genes and fraternal twins who share half their segregating genes to assess the
balance of genetic, shared family environment, and nonshared environment influences on dyslexia and on individual differences
across the normal range. We have learned that among the children we have studied in Colorado, group deficits in reading (dyslexia)
and individual differences in reading across the normal range are primarily due to genetic influences, and these genetic influences
are often shared with some of the same genetic influences on deficits and individual differences in language and ADHD. We
have also learned from our molecular-genetic linkage studies that there are regions on several chromosomes likely to contain
genes that influence dyslexia. Several specific genes within these regions have been tentatively identified through molecular-genetic
association analyses, but much more research is needed to understand the pathways among specific genes, regions of noncoding
DNA that regulate the activity of those genes, the brain, and dyslexia. I conclude with a discussion of our research on individual
differences in early reading development, on the role of early learning constraints in dyslexia, and on how genetic influences
are expressed through their interaction and correlation with the environment. 相似文献
14.
Petrill SA Deater-Deckard K Thompson LA Dethorne LS Schatschneider C 《Journal of learning disabilities》2006,39(1):48-55
The present study combined parallel data from the Northeast-Northwest Collaborative Adoption Projects (N2CAP) and the Western Reserve Reading Project (WRRP) to examine sibling similarity and quantitative genetic model estimates for measures of reading skills in 272 school-age sibling pairs from three family types (monozygotic twins, dizygotic twins, and unrelated adoptive siblings). The study included measures of letter and word identification, phonological awareness, phonological decoding, rapid automatized naming, and general cognitive ability. Estimates of additive genetic effects and shared environmental effects were moderate and significant. Furthermore, shared environmental effects estimated in twins were generally similar in magnitude to adoptive sibling correlations, suggesting highly replicable estimates across different study designs. 相似文献
15.
Stephen A. Petrill Kirby Deater-Deckard Lee Anne Thompson Chris Schatschneider Laura S. DeThorne David J. Vandenbergh 《Reading and writing》2007,20(1-2):127-146
We examined the genetic and environmental contribution to the stability and instability of reading outcomes in early elementary
school using a sample of 283 twin pairs drawn from the Western Reserve Reading Project. Twins were assessed across two measurement
occasions. In Wave 1, children were either in kindergarten or first grade. Wave 2 assessments were conducted one year later.
Results suggested substantial genetic stability across measurement occasions. Additionally, shared environmental influences
also accounted for stability, particularly for variables more closely tied to direct instruction such as phonological awareness,
letter knowledge, and word knowledge. There was also evidence for independent genetic and shared environmental effects, suggesting
that new sources of variance may emerge as the demands of school change and children begin to acquire early reading skills. 相似文献
16.
In order to assess the etiology of reading disability as a function of mathematics performance, data from 168 monozygotic (MZ) and 127 same-sex dizygotic (DZ) twin pairs in which at least one member of each pair was reading-disabled were subjected to quantitative genetic analyses. MZ and DZ concordance rates for reading disability were computed for different levels of mathematics performance, and reading performance data were fitted to an extension of the basic multiple regression model for the analysis of selected twin data. Results of these analyses suggest that genetic factors may be especially salient as a cause of reading disability in children with borderline deficits in mathematics performance: thus, mathematics performance may be a valid dimension for diagnosing subtypes of reading disability. 相似文献
17.
Brian Byrne Cara Delaland Ruth Fielding-Barnsley Peter Quain Stefan Samuelsson Torleiv Høien Robin Corley John C. DeFries Sally Wadsworth Erik Willcutt Richard K. Olson 《Annals of dyslexia》2002,52(1):47-73
We have initiated parallel longitudinal studies in Australia (Byrne, PI), the United States (Olson, PI), and Norway (Samuelsson,
PI) of identical and fraternal twins who are being tested in preschool for prereading skills, and in kindergarten, first grade,
and second grade for the development of early reading, spelling, and related cognitive skills. Comparisons of the similarities
of identical and fraternal twins will reveal the relative influence of genetic, shared family environment, and nonshared environment
on individual differences at and across different stages of development. Family and twin-specific environmental information
is also being directly assessed through parent questionnaires and observations by testers. Most of the data collected so far
have been from preschool twins (146 in Australia, 284 in the United States, and 70 in Norway). Preliminary analyses for the
preschool cognitive measures showed reliable genetic influences on phonological awareness and several measures of memory and
learning. In contrast, vocabulary, grammar, and morphology showed significant shared environment and negligible genetic effects.
A print knowledge composite showed both genetic and shared environment influence. 相似文献
18.
Sara A. Hart Stephen A. Petrill Lee A. Thompson 《Learning and individual differences》2010,20(2):63-69
The present study examined the phenotypic and genetic relationship between fluency and non-fluency-based measures of reading and mathematics performance. Participants were drawn from the Western Reserve Reading and Math Project, an ongoing longitudinal twin project of same-sex MZ and DZ twins from Ohio. The present analyses are based on tester-administered measures available from 228 twin pairs (age M = 9.86 years). Measurement models suggested that four factors represent the data, namely Decoding, Fluency, Comprehension, and Math. Subsequent quantitative genetic analyses of these latent factors suggested that a single genetic factor accounted for the covariance among these four latent factors. However, there were also unique genetic effects on Fluency and Math, independent from the common genetic factor. Thus, although there is a significant genetic overlap among different reading and math skills, there may be independent genetic sources of variation related to measures of decoding fluency and mathematics. 相似文献
19.
K. Gross-Glenn Bonnie Jallad Loriana Novoa Valerie Helgren-Lempesis H. A. Lubs 《Reading and writing》1990,2(2):161-173
We examined Nonsense-Passage oral reading in adults, using data derived from new and previously published studies (Finucci et al 1976, Gross-Glenn et al 1985). Time-scores and error-frequency data are presented for five samples of non-dyslexic readers with a minimum of a high-school education and no childhood history of dyslexia (N=127). Considerable uniformity is demonstrated across these samples, and reading performance of non-dyslexic individuals contrasts sharply with that observed in four samples of adult familial dyslexics. Both affected and compensated-affected dyslexic subjects read the passages significantly more slowly and with more errors than did nondyslexic readers. Results are discussed in relation to the cognitive and neural processes that may underlie this specific reading difficulty in dyslexics. We have found Nonsense-Passage reading to be especially useful in family studies of inherited dyslexia as a means of quantifying oral reading deficits in adults who have learned to compensate for their children reading difficulties. 相似文献
20.
Jesse L. Hawke Sally J. Wadsworth Richard K. Olson John C. DeFries 《Reading and writing》2007,20(1-2):13-25
To test the hypothesis that the etiology of reading difficulties may differ for males and females in more severely impaired
samples, reading performance data from monozygotic (MZ), same-sex dizygotic (DZss), and opposite-sex dizygotic (DZos) twin pairs were analyzed using a model-fitting implementation of the DeFries-Fulker (DF) model (Purcell & Sham, 2003, Behavior genetics, 33, 271–278). Five non-independent samples were selected using cut-offs of −1 (N = 737 pairs), −1.5 (N = 654), −2 (N = 468), −2.5 (N = 335), and −3 (N = 198) standard deviations (s) below the mean composite reading score of control twins. Male/female gender ratios for children
with reading difficulties were significantly higher than 1.0 for all five samples and increased as a function of severity
(viz., 1.15, 1.17, 1.40, 1.61, and 1.88, respectively). When the DF model was fit to the data, estimates of heritability (h
g2) and shared environmental influences (c
g2) were not significantly different for males and females in any of the groups. Consequently, the most parsimonious model that
provided a good fit to the data at all five levels of severity equated the heritabilities and shared environmental influences
for males and females, and fixed the DZos coefficient of genetic relatedness at 0.5. Thus, these results provide no evidence for a differential etiology of reading
difficulties as a function of gender in more severely impaired samples, and suggest that the same genetic and environmental
influences contribute to reading difficulties in males and females, irrespective of severity. 相似文献