Several aspects of early language skills, including parent-report measures of vocabulary, phoneme discrimination, speech segmentation, and speed of lexical access predict later childhood language outcomes. To date, no studies have examined the long-term predictive validity of novel word learning. We examined whether individual differences in novel…

Several aspects of early language skills, including parent-report measures of vocabulary, phoneme discrimination, speech segmentation, and speed of lexical access predict later childhood language outcomes. To date, no studies have examined the long-term predictive validity of novel word learning. We examined whether individual differences in novel…

Lynn (2010a, 2010b) argued that individuals from south Italy have a lower IQ than individuals from north Italy, and that these differences in IQ are at the basis of north-south gap in income, education, infant mortality, stature, and literacy. In the present paper, we discuss several theoretical and methodological aspects which we regard as flaws…

Multilevel modeling was used to address the longitudinal stability of standard scores (SSs) measuring intellectual ability for children with Williams syndrome (WS). Participants were 40 children with genetically confirmed WS who completed the Kaufman Brief Intelligence Test--Second Edition (KBIT-2; A. S. Kaufman & N. L. Kaufman, 2004) 4-7…

Across languages, children with developmental dyslexia are known to have impaired lexical phonological representations. Here, we explore associations between learning new phonological representations, phonological awareness, and sensitivity to amplitude envelope onsets (rise time). We show that individual differences in learning novel phonological…

A local processing bias, referred to as "weak central coherence," has been postulated to underlie key aspects of autism spectrum disorder (ASD). Little research has examined whether individual differences in this cognitive style can be found in typical development, independent of intelligence, and how local processing relates to executive control.…

Previous event-related potential (ERP) studies have revealed that faces and words show a robust difference in the lateralization of their N170. The present study investigated the development of this differential lateralization in school-age boys. We assessed the potential role of fetal testosterone (FT) level as a factor biasing the prenatal…

In a longitudinal genetic study we explored which factors underlie stability in verbal and nonverbal abilities, and the extent to which the association between these abilities becomes stronger as children grow older. Measures of verbal and nonverbal IQ were collected in Dutch twin pairs at age 5, 7, 10, 12 and 18 years. The stability of both…

Data from the national standardization of the French version of the WISC-III were analyzed to determine when during childhood the IQ-related process of differentiation appears and how the strength of the relationships among subtests evolves with age in low- and high-IQ groups. Indeed, some recent studies suggest that age might moderate the effect…

Individual growth curves were used to test whether the development of children with reading disabilities is best characterized by models of developmental lag or developmental deficit. Results with 403 children suggest that the developmental course of reading disabilities is best characterized by deficit models. (SLD)

Explored genetic and environmental etiologies of individual differences in printed word recognition and related skills in identical and fraternal twin 8- to 18-year-olds. Found evidence for moderate genetic influences common between IQ, phoneme awareness, and word-reading skills and for stronger IQ-independent genetic influences that were common…

This editorial proposes that the dependent variables that predict childhood intelligence quotient (IQ) from habituation and recognition memory assessments made during infancy may primarily reflect individual differences in rate of information processing. Inhibition may be a stable thread in mental development. (Author/SLD)

Testing, both in childhood and as adults, of 28 former pupils of special schools for the educable mentally retarded indicated that pupils who experienced most serious problems in childhood were less retarded as adults than persons who had experienced few or no problems. Results support hypothesis that the effects of early lack of environmental…

Examined the etiology of individual differences in literacy, phonological awareness, and language ability in monozygotic and dizygotic twins. Found that there was no genetic link between phonological awareness and literacy independent of general language ability. Individual differences in literacy ability were substantially influenced by genetics…

The case is made for basing analysis of longitudinal data on each subject's curve of scores. In this analysis of IQ scores from a longitudinal study, fitted curves yielded significant error reduction, rendering untenable the doctrine of IQ constancy. A visual method of curve classification is also presented. (Author/SJL)