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1.
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   

2.
The basic multiple regression model for the analysis of selected twin data (DeFries and Fulker 1985, 1988) was fitted to spelling data from 100 pairs of MZ twins and 71 pairs of same-sex DZ twins tested in the Colorado Reading Project (DeFries, Olson, Pennington and Smith 1991), and to data from 12 pairs of MZ twins and 15 pairs of same-sex DZ twins tested in the London twin study of reading disability (Stevenson, Graham, Fredman and McLoughlin 1984, 1987). Estimates of h g 2 obtained from analyses of these data suggest that about 60% of the deficit of probands is due to heritable influences in both samples. When a regression model was fitted separately to data from males and females in the combined Colorado and London samples, resulting estimates of h g 2 were 0.66±0.18 and 0.56±0.19, respectively, a nonsignificant difference. Collaborative analyses of data from additional twin studies of reading disability would facilitate more rigorous tests of hypotheses of differential genetic etiology as a function of group membership.  相似文献   

3.
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   

4.
The present study examined the etiology of highreading ability in an overall sample of 350twin pairs in which at least one member of 100pairs (54 MZ, 46 DZ) had a reading compositescore one standard deviation above the sample mean. These highreaders also had significantly higher scoresthan the rest of the sample on Full Scale,Verbal and Performance IQ scores, as well as onmeasures of phoneme awareness, orthographiccoding, phonological decoding, and verbalshort-term memory. The MZ proband-wiseconcordance rate for high group membership wassignificantly higher than the DZ proband-wiseconcordance rate and further behavioralgenetic analyses corroborated that high readingability is partly due to genetic influence(h2 g = 0.55 ± 0.22). Bivariatemultiple regression analyses demonstrated thathigh phonological awareness, orthographiccoding, phonological decoding, and short-termverbal memory skills all share significantcommon genetic influence with high readingability. These results suggest that readingability and its cognitive correlates are on acontinuous distribution, with both extremes ofthe distribution being similarly heritable. They also support the hypothesis that the samecognitive processes that are associated withdyslexia are important for the development ofhigh reading ability.  相似文献   

5.
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.
D C Rowe 《Child development》1983,54(2):416-423
Biometrical genetic analysis was applied to sibling and twin kinship data on 2 dimensions of perceived home environment. Correlations on 1 dimension, Restrictiveness-Permissiveness, were equal and significant for all kinships: MZ twins, DZ twins, same-sex siblings, and opposite-sex siblings significant for all 4 kinships: MZ twins, DZ twins, same-sex siblings, and opposite-sex siblings (r greater than .40). An E2-E1 biometrical model fitted Restrictiveness-Permissiveness, implying that treatments common to siblings create agreement about perceived environment. As intrapair differences were the same for all 4 kinships under this model, the equal environments assumption of the twin method was supported. In contrast, the Acceptance-Rejection dimension fitted a G-E1 model that makes the assumption that sibling similarity is the result of genetic factors and postulates an absence of shared environmental influences. This finding suggests that this aspect of home environment may depend as much on the child's inherited traits as on actual treatments and is in accord with the genetic analysis of individual traits in that developmentally effective environmental factors do not appear to be common to siblings.  相似文献   

7.
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   

8.
Differential genetic etiology of reading disability as a function of IQ   总被引：5，自引：0，他引：5  
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   

9.
This report presents data on 9-month-old twin pairs (n(MZ)=172; n(DZ)=333) from the Early Childhood Longitudinal Study, demonstrating that the role of genetic variation among infants is trivial and the shared and nonshared environment is substantial in accounting for the observed quality of infant-caregiver relationships. In contrast, maternal reports of temperament were best accounted for by genetic variation and nonshared environmental influences. Interestingly, however, shared environmental effects were documented for observations of temperament. Consistent with a growing database, the current study calls into question the ubiquity of heritability effects in all domains of psychological inquiry. It also bolsters consensus in the field of developmental psychology that shared environmental effects are not as elusive as had once been thought.  相似文献   

10.
Generalist Genes: Genetic Links Between Brain, Mind, and Education   总被引：1，自引：0，他引：1  
ABSTRACT— Genetics contributes importantly to learning abilities and disabilities—not just to reading, the target of most genetic research, but also to mathematics and other academic areas as well. One of the most important recent findings from quantitative genetic research such as twin studies is that the same set of genes is largely responsible for genetic influence across these domains. We call these "generalist genes" to highlight their pervasive influence. In other words, most genes found to be associated with a particular learning ability or disability (such as reading) will also be associated with other learning abilities and disabilities (such as mathematics). Moreover, some generalist genes for learning abilities and disabilities are even more general in their effect, encompassing other cognitive abilities such as memory and spatial ability. When these generalist genes are identified, they will greatly accelerate research on general mechanisms at all levels of analysis from genes to brain to behavior.  相似文献   

11.
The genetic and environmental contributions to children's maladaptive behavior are assessed in a sample of 154 twin pairs (77 MZ twin pairs and 77 DZ twin pairs), who range in age from 6 to 11 years. To bridge the strengths of behavioral genetic methods and environmental assessment techniques, we use a multimethod, multimeasure approach to data collection, and analyze the data using behavioral genetic modeling techniques. Results indicate that genetic variation accounts for a majority of the variance in parent-reported child maladaptive behavior (average = 62%). One parent-report measure also suggests a smaller, significant contribution of shared environmental variance. In contrast to the parental ratings, the observational coding and global impressions of parent-twin interactive behavior suggest that shared environment is the primary source of variance accounting for parent and child maladaptive behavior. This is due, in part, to the direct influence one's interactive partner has on the expression of maladaptive behavior in an interactive setting. When controlling for the co-participant's behavior, genetic variation increases and shared environmental variation decreases.  相似文献   

12.
Federal policy on alternate assessment based on modified academic achievement standards (AA-MAS) inspired this research. Specifically, an experimental study was conducted to determine whether tests composed of modified items would have the same level of reliability as tests composed of original items, and whether these modified items helped reduce the performance gap between AA-MAS eligible and ineligible students. Three groups of eighth-grade students (N?=?755) defined by eligibility and disability status took original and modified versions of reading and mathematics tests. In a third condition, the students were provided limited reading support along with the modified items. Changes in reliability across groups and conditions for both the reading and mathematics tests were determined to be minimal. Mean item difficulties within the Rasch model were shown to decrease more for students who would be eligible for the AA-MAS than for non-eligible groups, revealing evidence of differential boost. Exploratory analyses indicated that shortening the question stem may be a highly effective modification, and that adding graphics to reading items may be a poor modification.  相似文献   

13.
Previous twin studies of reading disability employed a comparison of concordance rates in identical and fraternal twin pairs as a test for genetic etiology. Recently, a statistically more powerful multiple regression analysis of twin data has been formulated to assess the importance of genetic factors in the development of reading difficulties. Application of this analysis to twin data from the Colorado Reading Project yields definitive evidence for a genetic etiology. Results from this study suggest that approximately 40 percent of the deficit observed in the disabled readers is due to genetic factors, 35 percent is due to environmental influences shared by members of twin pairs, and about 25 percent is the result of environmental factors unique to the individual and/or error variance. This work was supported in part by a program project grant from the NICHD (HD-11681).  相似文献   

14.
Neonatal Temperament in Monozygotic and Dizygotic Twin Pairs   总被引：1，自引：0，他引：1  
To determine if neonatal temperament was influenced by genetic factors, temperament was assessed in 316 newborn twins from 47 pairs of monozygotic (MZ) twins, 39 pairs of same-sex dizygotic (DZ) twins, and 72 pairs of opposite-sex dizygotic twins. The neonatal assessment focused on irritability, resistance to soothing, activity level, reactivity, and reinforcement value. Examination of intraclass correlations for MZ and DZ twins and the results of model-fitting analyses indicated that heritability estimates for neonatal temperament were not significantly different from zero, and that there was substantial environmental influence on neonatal temperament. Specific perinatal indicators of risk were found to account for some of the intrapair differences observed for the behavioral variables. It was concluded that there is no clear pattern of genetic influence on temperament in the neonatal period.  相似文献   

15.
We explored the genetic background of individual differences in dynamic measures of verbal learning ability in children, using a Dutch version of the Auditory Verbal Learning Test (AVLT). Nine-year-old twin pairs (N = 112 pairs) were recruited from the Netherlands Twin Register. When possible, an older sibling between 10 and 14 years old participated as well (N = 99). To assess verbal learning, non-linear curves were fitted for each child individually. Two parameters were estimated: Learning Speed (LS) and Forgetting Speed (FS). Larger twin correlations in monozygotic (MZ) than in dizygotic (DZ) and sibling pairs for LS and FS indicated the importance of genetic factors in explaining variation in these traits. The heritability estimate (percentage of variance explained by genetic factors) for LS was 43% for both twins and siblings. For FS heritability was estimated at 20% in twins and was slightly higher (30%) in their older siblings.  相似文献   

16.
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   

17.
In Italy, from the 2003 reports to the present, the National Institute for the Educational Evaluation of Instruction and Training (INVALSI) has conducted research on Programme for International Student Assessment (PISA) results in order to understand Italian students’ low achievement in mathematics. In the present paper, data from a representative sample of 15-year-old Italian students who participated in PISA 2012 were analysed. This study’s primary aim is to verify how students’ linguistic competences are associated with their performance in mathematics. For the evaluation of the impact of item reading demand on students’ performance, we selected 24 mathematics items with a high reading demand and 31 mathematics items with a low reading demand, as classified by Italian language and methodology experts. Repeated measure variance analyses were conducted. The results showed differences in function of gender: females are advantaged in mathematics items with a high reading demand, independent of their level of reading literacy. In contrast, males are advantaged in mathematics items with a low reading demand, independent of their level of reading literacy. Possible policy implications are discussed.  相似文献   

18.
Limited research has examined the skills of children with a reading disability (RD) and children with RD and a mathematics disability (MD). Even less research has examined the phonological awareness (PA) and rapid automatized naming (RAN) skills in these two groups of children and how these skills relate to reading and math achievement. Additionally, various classification criteria are frequently implemented to classify children with MD. The purpose of this study, therefore, was to examine the PA and RAN skills in children who met different criteria for RD only and children with RD who are at risk for mathematics difficulties (MDR). Participants were 114 second‐ or third‐grade students with RD from public elementary schools in three large metropolitan areas. Students were classified as at risk for mathematics difficulties utilizing a 25th‐percentile cutoff and a 15th‐percentile cutoff as assessed by the KeyMath‐Revised Test ( Connolly, 1988 ). A series of PA and RAN measures were administered along with a range of reading and mathematics measures. Hierarchical regression analyses indicated that children with RD only evidenced a different pattern of results compared to children with RD + MDR. Additionally, using a more stringent criterion to classify children at risk for mathematics difficulties resulted in a differential pattern of results when compared to a less stringent classification criterion.  相似文献   

19.
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20.
Although assessments of mathematics, reading, and writing are assumed to measure distinct academic skills, this may be difficult owing to the pervasive influence of general ability on performance. Factor analyses of school-level data from 14 large-scale assessment programs revealed that 80% of the variance in mathematics, reading, and writing scores was due to a common, underlying factor. Multiple regression analyses confirmed that scores contribute little information that is unique to a particular subject (6% or less). Although different assessments may create the illusion of providing unique information, they may be tapping into generic cognitive abilities that cut across content areas. These results raise suspicions about the value and validity of interpretations based on school-level subject area scores.  相似文献   

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