Given the importance of writing for academic achievement, this study aimed to understand how early oral language contributes to later writing skills. The first objective was to determine if preschool language skills were associated with high school writing, and if so, whether they contributed directly or indirectly through school age language. The…

This twin study examined the genetic and environmental etiology of vocabulary, syntax, and their association in first graders. French-speaking same-sex twins (n = 555) completed two vocabulary tests, and two scores of syntax were calculated from their spontaneous speech at 7 years of age. Multivariate latent factor genetic analyses showed that…

Recent studies have begun to uncover the genetic architecture of educational attainment. We build on this work using genome-wide data from siblings in the National Longitudinal Study of Adolescent to Adult Health (Add Health). We measure the genetic predisposition of siblings to educational attainment using polygenic scores. We then test how…

This study assessed the utility of a brief assessment (the Peabody Picture Vocabulary Test-4th Edition; PPVT4) as a proxy for verbal IQ (VIQ) in large-scale studies of autism spectrum disorder (ASD). In a sample of 2,420 proband with ASD, PPVT4:IQ correlations were strong. PPVT4 scores were, on average, 5.46 points higher than VIQ; 79% of children…

Observational studies have shown that caregiver sensitivity predicts child language skills. These studies, however, have entirely relied on between-family designs (single parent-child dyad per family), which cannot rule out the contribution of shared family confounds (e.g., genetics, books in home). The current study investigates whether observed…

This study considered how far nonverbal cognitive, language and reading abilities are affected by common genetic influences in a sample of 312 typically developing Chinese twin pairs aged from 3 to 11 years. Children were individually given tasks of Chinese word reading, receptive vocabulary, phonological memory, tone awareness, syllable and rhyme…

A fairly recent definition of reading disability (RD) is that in the form of a hybrid model. The model views RD as a latent construct that is manifested through various observable unexpected impairments in reading-related skills and through inadequate response to intervention. The current report evaluated this new conceptualization of RD from an…

Purpose: Multiple factors impact reading acquisition in individuals with reading disability, including genetic disorders such as Williams syndrome (WS). Despite a relative strength in oral language, individuals with WS usually have an intellectual disability and tend to display deficits in areas associated with reading. There is substantial…

There has been significant interest in examining the developmental factors that predispose individuals to chronic criminal offending. This body of research has identified some social-environmental risk factors as potentially important. At the same time, the research producing these results has generally failed to employ genetically sensitive…

Impulsivity and inattention are key constructs at the interface of temperament and domains of childhood behavioral problems, such as ADHD and ODD. A multi-method, multi-source assessment of impulsivity and inattention was conducted with 256 families of twins at a mean age of 8-9 years from an epidemiologically defined community sample. Analysis of…

Little evidence supports that siblings with autism exhibit the same behaviors; however, some findings suggest that level of functioning shows familial aggregation. We tested this notion among multiplex families participating with the Autism Genetic Resource Exchange (AGRE) Consortium, using scores on the "Peabody Picture Vocabulary Test-Third…

Evidence from intervention studies, quantitative genetic and molecular genetic studies suggests that genetic, and to a lesser extent, shared environmental influences are important to the development of reading and related cognitive skills. The Northeast-Northwest Collaborative Adoption Projects (N2CAP) is a sample of 241 adoptive families,…

This paper focuses on the communication and language phenotypes associated with three genetic disorders: Down syndrome, Williams syndrome, and fragile X syndrome. It is argued that there is empirical evidence that these disorders predispose children to specific profiles of strength and weakness in some areas of speech, language, and communication,…

Author focused on differences between whites and negroes in the United States and more generally on racial variation in man. (Author/RK)

Purpose: The biological mechanisms underlying developmental stuttering remain unclear. In a previous investigation, we showed that there is significant spatial correspondence between regional gray matter structural anomalies and the expression of genes linked to energy metabolism. In the current study, we sought to further examine the relationship…