Differentiation hypotheses concern changes in the structural organization of cognitive abilities that depend on the level of general intelligence (ability differentiation) or age (developmental differentiation). Part 1 of this article presents a review of the literature on ability and developmental differentiation effects in children, revealing…

We examined the predictive value of early spelling for later reading performance by analyzing data from 970 U.S. children whose spelling was assessed in the summer following the completion of kindergarten (M age = 6 years; 3 months). The word reading performance of most of the children was then tested after the completion of Grade 1 (age 7;5),…

ASD symptomology and behavioral problems pose challenges for children with ASD in school. Disagreement between parents and teachers in ratings of children's behavior problems may provide clinically relevant information. We examined parent-teacher disagreement on ratings of behavior problems among children with ASD during the fall and spring of the…

The present study investigated the moderating role of orthographic consistency on the development of reading comprehension in four language groups (English, n = 179; Spanish, n = 188; Czech, n = 135; Slovak, n = 194) from kindergarten to Grade 2. In all languages, early variations in phoneme awareness/letter knowledge, rapid automatised naming,…

Do children who go on to develop dyslexia show normal verbal and nonverbal development before reading onset? According to the aptitude-achievement discrepancy model, dyslexia is defined as a discrepancy between intelligence and reading achievement. One of the underlying assumptions is that the general cognitive development of children who fail to…

We studied developmental trends in 5 important reasoning tasks that are critical components of the operational definition of rational thinking. The tasks measured denominator neglect, belief bias, base rate sensitivity, resistance to framing, and the tendency toward otherside thinking. In addition to age, we examined 2 other individual difference…