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Robert Plomin - One of the best experts on this subject based on the ideXlab platform.
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math fluency is etiologically distinct from untimed math performance decoding fluency and untimed reading performance evidence from a twin study
Journal of Learning Disabilities, 2012Co-Authors: Stephen A Petrill, Lee A Thompson, Yulia Kovas, Jessica A R Logan, Sara A Hart, Pamela Vincent, Robert PlominAbstract:The authors examined whether math fluency was independent from untimed math and from reading using 314 pairs of school-aged twins drawn from the Western Reserve Reading and Math Projects. Twins were assessed through a 90-min home visit at approximately age 10 and were reassessed in their homes approximately 1 year later. Results suggested that the Shared Environment and genetics influenced the covariance among math fluency, untimed math measures, and reading measures. However, roughly two thirds of the variance in math fluency was independent from untimed math measures and reading, including reading fluency. The majority of this independent variance was the result of genetic factors that were longitudinally stable across two measurement occasions. These results suggest that math fluency, although related to other math measures, may also be a genetically distinct dimension of mathematics performance.
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the etiology of mathematical self evaluation and mathematics achievement understanding the relationship using a cross lagged twin study from ages 9 to 12
Learning and Individual Differences, 2011Co-Authors: Yu L L Luo, Yulia Kovas, Claire M A Haworth, Robert PlominAbstract:The genetic and Environmental origins of individual differences in mathematical self-evaluation over time and its association with later mathematics achievement were investigated in a UK sample of 2138 twin pairs at ages 9 and 12. Self-evaluation indexed how good children think they are at mathematical activities and how much they like those activities. Mathematics achievement was assessed by teachers based on UK National Curriculum standards. At both ages self-evaluation was approximately 40% heritable, with the rest of the variance explained by non-Shared Environment. The results also suggested moderate reciprocal associations between self-evaluation and mathematics achievement across time, with earlier self-evaluation predicting later performance and earlier performance predicting later self-evaluation. These cross-lagged relationships were genetically rather than Environmentally mediated.
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commentary why are children in the same family so different non Shared Environment three decades later
International Journal of Epidemiology, 2011Co-Authors: Robert PlominAbstract:The importance of non-Shared Environment lay hidden within quantitative genetic studies since they began nearly a century ago. Quantitative genetic methods, such as twin and adoption methods, were designed to tease apart nature and nurture in order to explain family resemblance. For nearly all complex phenotypes, it has emerged that the answer to the question of the origins of family resemblance is nature—things run in families primarily for genetic reasons. However, the best available evidence for the importance of Environmental influence comes from this same quantitative genetic research because genetic influence never explains all of the variance for complex phenotypes, and the remaining variance must be ascribed to Environmental influences. Yet it took many decades for the full meaning of these findings to emerge. If genetics explains why siblings growing up in the same family are similar, but the Environment is important, then it must be the case that the salient Environmental effects do not make siblings similar. That is, they are not Shared by children growing up in the same family—they must be ‘non-Shared’. This implication about non-Shared Environmental import lay fallow in the field of quantitative genetics because the field’s attention was then firmly on the nature–nurture debate. ‘Nurture’ in the nature–nurture debate was implicitly taken to mean Shared Environment because from Freud onwards, theories of socialization had assumed that children’s Environments are doled out on a family-by-family basis. In contrast, the point of non-Shared Environment is that Environments are doled out on a child-by-child basis. Note that the phrase ‘non-Shared Environment’ is shorthand for a component of phenotypic variance—it refers to ‘effects’ rather than ‘events’, as discussed later. The 1987 paper reprinted in this issue of the International Journal of Epidemiology1 brought together evidence for the importance of non-Shared Environment in the development of personality, psychopathology and cognitive abilities, expanding on a previous paper.2 The purpose of the present commentary is to reflect on non-Shared Environment three decades after the topic emerged. Progress and problems in studying non-Shared Environment were reviewed in 2001;3 rather than providing a systematic update of this burgeoning field, my current goal is to suggest some new directions for research in this area. The 1987 paper was published with 32 commentaries and our response,4 which I recommend. These commentaries and the response to them raised many of the issues that resurfaced during the following decades, such as the following: Non-Shared Environmental effects need to be distinguished from error of measurement (yes). Non-additive genetic variance can account for non-Shared Environmental effects (no). Genotype–Environment interaction and correlation can account for non-Shared Environmental effects (no). Prenatal factors can contribute to non-Shared Environmental effects (yes). Non-Shared Environmental effects may be more influential in extreme situations such as abusive families (yes). Perceptions of Environment can be an important source of non-Shared experience (yes). Non-Shared Environment can involve chance in the sense of idiosyncratic experiences (yes).
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chaos in the home and socioeconomic status are associated with cognitive development in early childhood Environmental mediators identified in a genetic design
Intelligence, 2004Co-Authors: Stephen A Petrill, Alison Pike, Thomas S Price, Robert PlominAbstract:The current study examined whether socioeconomic status (SES) and chaos in the home mediate the Shared Environmental variance associated with cognitive functioning simultaneously estimating genetic influences in a twin design. Verbal and nonverbal cognitive development were assessed at 3 and 4 years for identical and same-sex fraternal twin pairs participating in the Twins Early Development Study (TEDS). Verbal and nonverbal skills were measured using the McArthur Scales of Language Development (VERBAL) and the Parent Report of Children's Abilities (PARCA), respectively. SES and chaos were assessed via questionnaire. Results suggest that SES and CHAOS mediate an independent and significant, but modest, portion of the Shared Environment for VERBAL and PARCA at Ages 3 and 4.
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genetic influence on language delay in two year old children
Nature Neuroscience, 1998Co-Authors: Philip S. Dale, Thomas S Price, Thalia C Eley, Jim Stevenson, Emily Simonoff, Dorothy V M Bishop, Bonny Oliver, Shaun Purcell, Robert PlominAbstract:Previous work suggests that most clinically significant language difficulties in children do not result from acquired brain lesions or adverse Environmental experiences but from genetic factors that presumably influence early brain development. We conducted the first twin study of language delay to evaluate whether genetic and Environmental factors at the lower extreme of delayed language are different from those operating in the normal range. Vocabulary at age two was assessed for more than 3000 pairs of twins. Group differences heritability for the lowest 5% of subjects was estimated as 73% in model-fitting analyses, significantly greater than the individual differences heritability for the entire sample (25%). This supports the view of early language delay as a distinct disorder. Shared Environment was only a quarter as important for the language-delayed sample (18%) as for the entire sample (69%).
Paulo H Ferreira - One of the best experts on this subject based on the ideXlab platform.
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does educational attainment increase the risk of low back pain when genetics are considered a population based study of spanish twins
The Spine Journal, 2017Co-Authors: Joshua R Zadro, Debra Shirley, Marina B Pinheiro, Juan F Sanchezromera, Francisco Perezriquelme, Juan R Ordonana, Paulo H FerreiraAbstract:Abstract Background Context There is limited research investigating educational attainment as a risk factor for low back pain (LBP), with the influence of gender commonly being neglected. Furthermore, genetics and early Shared Environment explain a substantial proportion of LBP cases and need to be controlled for when investigating risk factors for LBP. Purpose To investigate whether educational attainment affects the prevalence and risk of LBP differently in men and women while controlling for the influence of genetics and early Shared Environment. Study Design This is a cross-sectional and prospective twin case-control study. Patient Sample Adult monozygotic (MZ) and dizygotic (DZ) twins from the Murcia Twin Registry, with available data on educational attainment, formed the base sample for this study. The prevalence analysis considered twins with available data on LBP in 2013 (n=1,580). The longitudinal analysis considered twins free of LBP at baseline (2009–2011), with available data on LBP at follow-up (2013) (n=1,077). Outcome Measures Data on the lifetime prevalence of activity limiting LBP (outcome) and educational attainment (risk factor) were self-reported. Methods The prevalence analysis investigated the cross-sectional association between educational attainment and LBP, whereas the longitudinal analysis investigated whether educational attainment increased the risk of developing LBP. Both analyses were performed in the following sequence. First, a total sample analysis was performed on all twins (considering them as individuals), adjusting for confounding variables selected by the data. Second, to control for the influence of genetics and early Shared Environment, a within-pair case-control analysis (stratified by zygosity) was performed on complete twin pairs discordant for LBP (ie, one twin had LBP, whereas the co-twin did not). All analyses were stratified for gender where possible, with an interaction term determining whether gender was a significant moderator of the association between educational attainment and LBP. Results Women with either general secondary or university education were less likely to experience (prevalence analysis) or to develop LBP (longitudinal analysis). Educational attainment did not affect the risk of LBP in men. When controlling for the effects of genetics and early Shared Environment, the relationship between educational status and LBP in women was no longer statistically significant. Conclusions Educational attainment affects LBP differently in men and women, with higher levels of education only decreasing the risk of developing LBP in women. After adjusting for genetics and early Shared Environment, the relationship between educational attainment and LBP in women disappears. This suggests that genetics and early Shared Environment are confounding the relationship between educational attainment and LBP in women.
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are obesity and body fat distribution associated with low back pain in women a population based study of 1128 spanish twins
European Spine Journal, 2016Co-Authors: Amabile B Dario, Juan F Sanchezromera, Juan R Ordonana, Manuela L Ferreira, Kathryn M Refshauge, Alejandro Luquesuarez, John L Hopper, Paulo H FerreiraAbstract:Purpose To investigate the relationship between different measures of obesity and chronic low back pain (LBP) using a within-pair twin case–control design that adjusts for genetics and early Shared Environment. Methods A cross-sectional association between lifetime prevalence of chronic LBP and different measures of obesity (body mass index-BMI; percent body fat; waist circumference; waist–hip ratio) was investigated in 1128 female twins in three stages: (i) total sample analysis; (ii) within-pair case–control analysis for monozygotic (MZ) and dizygotic (DZ) twins together; (iii) within-pair case– control analysis separated by DZ and MZ. Odds ratios (OR) and 95 % confidence intervals (CI) were calculated. Results BMI (OR 1.12; 95 % CI 1.02–1.26) and percent body fat (OR 1.15; 95 % CI 1.01–1.32) were weakly associated with lifetime prevalence of chronic LBP in the total sample analysis but were absent when Shared Environment and genetic factors were adjusted for using the within-pair case–control analysis. Greater waist–hip ratios were associated with smaller prevalence estimates of chronic LBP in the within-pair case–control analysis with both MZ and DZ twins (OR 0.67; 95 % CI 0.47–0.94). However, this association did not remain after the full adjustment for genetic factors in the MZ within-pair case– control analysis. Conclusions BMI, percent of fat mass and greater depositions of fat and mass around the hips are associated with increases in chronic LBP prevalence in women but these associations are small and appear to be confounded by the effects of genetics and early Shared Environment. Therefore, our results do not support a causal direct relationship between obesity and chronic LBP.
Henrik Larsson - One of the best experts on this subject based on the ideXlab platform.
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genetic and Environmental sources of familial coaggregation of obsessive compulsive disorder and suicidal behavior a population based birth cohort and family study
Molecular Psychiatry, 2019Co-Authors: Anna Sidorchuk, Paul Lichtenstein, Henrik Larsson, Brian M Donofrio, Ralf Kujahalkola, Bo Runeson, Christian Ruck, David MataixcolsAbstract:Obsessive−compulsive disorder (OCD) is associated with high risk of suicide. It is yet unknown whether OCD and suicidal behaviors coaggregate in families and, if so, what are the mechanisms underlying this coaggregation. In a population-based birth cohort and family study, we linked individuals born in Sweden in 1967–2003 (n = 3,594,181) to their parents, siblings, and cousins, and collected register-based diagnoses of OCD, suicide attempts, and deaths by suicide and followed them until December 31, 2013. We also applied quantitative genetic modeling to estimate the contribution of genetic and Environmental factors to the familial coaggregation of OCD and suicidal behavior. An elevated risk of suicide attempts was observed across all relatives of individuals with OCD, increasing proportionally to the degree of genetic relatedness, with odds ratios (OR) ranging from 1.56 (95% confidence interval (CI) 1.49–1.63) in parents to 1.11 (95% CI 1.07–1.16) in cousins. The risk of death by suicide also increased alongside narrowing genetic distance, but was only significant in parents (OR 1.55; 95% CI 1.40–1.72) and full siblings (OR 1.80; 95% CI 1.43–2.26) of individuals with OCD. Familial coaggregation of OCD and suicide attempts was explained by additive genetic factors (60.7%) and non-Shared Environment (40.4%), with negligible contribution of Shared Environment. Similarly, familial coaggregation with death by suicide was attributed to additive genetics (65.8%) and nonShared Environment (34.2%). Collectively, these observations indicate that OCD and suicidal behaviors coaggregate in families largely due to genetic factors. The contribution of unique Environment is also considerable, providing opportunities to target high-risk groups for prevention and treatment.
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psychopathic personality traits in 5 year old twins the importance of genetic and Shared Environmental influences
European Child & Adolescent Psychiatry, 2017Co-Authors: Catherine Tuvblad, Henrik Andershed, Kostas A Fanti, Olivier F Colins, Henrik LarssonAbstract:There is limited research on the genetic and Environmental bases of psychopathic personality traits in children. In this study, psychopathic personality traits were assessed in a total of 1189 5-year-old boys and girls drawn from the Preschool Twin Study in Sweden. Psychopathic personality traits were assessed with the Child Problematic Traits Inventory, a teacher-report measure of psychopathic personality traits in children ranging from 3 to 12 years old. Univariate results showed that genetic influences accounted for 57, 25, and 74 % of the variance in the grandiose–deceitful, callous–unemotional, and impulsive–need for stimulation dimensions, while the Shared Environment accounted for 17, 48 and 9 % (n.s.) in grandiose–deceitful and callous–unemotional, impulsive–need for stimulation dimensions, respectively. No sex differences were found in the genetic and Environmental variance components. The non-Shared Environment accounted for the remaining 26, 27 and 17 % of the variance, respectively. The three dimensions of psychopathic personality were moderately correlated (0.54–0.66) and these correlations were primarily mediated by genetic and Shared Environmental factors. In contrast to research conducted with adolescent and adult twins, we found that both genetic and Shared Environmental factors influenced psychopathic personality traits in early childhood. These findings indicate that etiological models of psychopathic personality traits would benefit by taking developmental stages and processes into consideration.
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longitudinal stability of genetic and Environmental influences on irritability from childhood to young adulthood
American Journal of Psychiatry, 2015Co-Authors: Roxann Robersonnay, Paul Lichtenstein, Melissa A. Brotman, Ellen Leibenluft, John Myers, Henrik Larsson, Kenneth S KendlerAbstract:Objective:Little is known about genetic influences on juvenile irritability and whether such influences are developmentally stable and/or dynamic. This study examined the temporal pattern of genetic and Environmental effects on irritability using data from a prospective, four-wave longitudinal twin study.Method:Parents and their twin children (N=2,620 children) from the Swedish Twin Study of Child and Adolescent Development reported on the children’s irritability, defined using a previously identified scale from the Child Behavior Checklist.Results:Genetic effects differed across the sexes, with males exhibiting increasing heritability from early childhood through young adulthood and females exhibiting decreasing heritability. Genetic innovation was also more prominent in males than in females, with new genetic risk factors affecting irritability in early and late adolescence for males. Shared Environment was not a primary influence on irritability for males or females. Unique, nonShared Environmental fac...
Erik G Willcutt - One of the best experts on this subject based on the ideXlab platform.
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longitudinal stability in reading comprehension is largely heritable from grades 1 to 6
PLOS ONE, 2015Co-Authors: Brooke Soden, Lee A Thompson, Janice M Keenan, Sally J Wadsworth, Erik G Willcutt, Micaela E Christopher, Jacqueline Hulslander, Laurie E Cutting, Stephen A PetrillAbstract:Reading comprehension is a foundational academic skill and significant attention has focused on reading development. This report is the first to examine the stability and change in genetic and Environmental influences on reading comprehension across Grades 1 to 6. This developmental range is particularly important because it encompasses the timespan in which most children move from learning how to read to using reading for learning. Longitudinal simplex models were fitted separately for two independent twin samples (N = 706; N = 976). Results suggested that the Shared Environment contributed to variance in early but not later reading. Instead, stability in reading development was largely mediated by continuous genetic influences. Thus, although reading is clearly a learned skill and the Environment remains important for reading development, individual differences in reading comprehension appear to be also influenced by a core of genetic stability that persists through the developmental course of reading.
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genetic and Environmental influences on vocabulary and reading development
Scientific Studies of Reading, 2011Co-Authors: Janice M Keenan, J C Defries, Brian Byrne, Stefan Samuelsson, William L Coventry, Robin P Corley, Sally J Wadsworth, Erik G Willcutt, Bruce F PenningtonAbstract: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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Environmental and genetic influences on prereading skills in australia scandinavia and the united states
Journal of Educational Psychology, 2005Co-Authors: Stefan Samuelsson, J C Defries, Brian Byrne, Robin P Corley, Sally J Wadsworth, Peter Quain, Erik G WillcuttAbstract: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.
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longitudinal twin study of early reading development in three countries preliminary results
Annals of Dyslexia, 2002Co-Authors: Brian Byrne, J C Defries, Stefan Samuelsson, Robin P Corley, Sally J Wadsworth, Cara Delaland, Ruth Fieldingbarnsley, Peter Quain, Torleiv Hoien, Erik G WillcuttAbstract: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.
Stephen A Petrill - One of the best experts on this subject based on the ideXlab platform.
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longitudinal stability in reading comprehension is largely heritable from grades 1 to 6
PLOS ONE, 2015Co-Authors: Brooke Soden, Lee A Thompson, Janice M Keenan, Sally J Wadsworth, Erik G Willcutt, Micaela E Christopher, Jacqueline Hulslander, Laurie E Cutting, Stephen A PetrillAbstract:Reading comprehension is a foundational academic skill and significant attention has focused on reading development. This report is the first to examine the stability and change in genetic and Environmental influences on reading comprehension across Grades 1 to 6. This developmental range is particularly important because it encompasses the timespan in which most children move from learning how to read to using reading for learning. Longitudinal simplex models were fitted separately for two independent twin samples (N = 706; N = 976). Results suggested that the Shared Environment contributed to variance in early but not later reading. Instead, stability in reading development was largely mediated by continuous genetic influences. Thus, although reading is clearly a learned skill and the Environment remains important for reading development, individual differences in reading comprehension appear to be also influenced by a core of genetic stability that persists through the developmental course of reading.
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math fluency is etiologically distinct from untimed math performance decoding fluency and untimed reading performance evidence from a twin study
Journal of Learning Disabilities, 2012Co-Authors: Stephen A Petrill, Lee A Thompson, Yulia Kovas, Jessica A R Logan, Sara A Hart, Pamela Vincent, Robert PlominAbstract:The authors examined whether math fluency was independent from untimed math and from reading using 314 pairs of school-aged twins drawn from the Western Reserve Reading and Math Projects. Twins were assessed through a 90-min home visit at approximately age 10 and were reassessed in their homes approximately 1 year later. Results suggested that the Shared Environment and genetics influenced the covariance among math fluency, untimed math measures, and reading measures. However, roughly two thirds of the variance in math fluency was independent from untimed math measures and reading, including reading fluency. The majority of this independent variance was the result of genetic factors that were longitudinally stable across two measurement occasions. These results suggest that math fluency, although related to other math measures, may also be a genetically distinct dimension of mathematics performance.
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chaos in the home and socioeconomic status are associated with cognitive development in early childhood Environmental mediators identified in a genetic design
Intelligence, 2004Co-Authors: Stephen A Petrill, Alison Pike, Thomas S Price, Robert PlominAbstract:The current study examined whether socioeconomic status (SES) and chaos in the home mediate the Shared Environmental variance associated with cognitive functioning simultaneously estimating genetic influences in a twin design. Verbal and nonverbal cognitive development were assessed at 3 and 4 years for identical and same-sex fraternal twin pairs participating in the Twins Early Development Study (TEDS). Verbal and nonverbal skills were measured using the McArthur Scales of Language Development (VERBAL) and the Parent Report of Children's Abilities (PARCA), respectively. SES and chaos were assessed via questionnaire. Results suggest that SES and CHAOS mediate an independent and significant, but modest, portion of the Shared Environment for VERBAL and PARCA at Ages 3 and 4.
