This paper reports the findings of an investigation aimed at gaining a clearer understanding of the nature of vocabulary difficulties associated with dyslexia and associated risk status. Three studies were conducted to examine preschoolers' access and mastery of syntactic- and phonological-based processes believed to support word learning. Results…

Genetic and environmental influences on prereading skills in preschool and on early reading and spelling development at the end of kindergarten were compared among samples of identical and fraternal twins from the U.S. (Colorado), Australia, and Scandinavia. Mean comparisons revealed significantly lower preschool print knowledge in Scandinavia,…

Grade 1 literacy skills of twin children in Australia (New South Wales) and the United States (Colorado) were explored in a genetically sensitive design (N = 319 pairs). Analyses indicated strong genetic influence on word and nonword identification, reading comprehension, and spelling. Rapid naming showed more modest, though reliable, genetic…

Numerous studies have examined the etiology of the association between reading difficulties and attention-deficit hyperactivity disorder (ADHD) in school-age children, but little is known about the relation between prereading skills and ADHD behaviors prior to the beginning of formal reading instruction. A population-based sample of 809 pairs of…

Newly literate children have a tendency to spell s-stop sequences in words like "spin," "stop," "sky" with B, D, G (SBIN, SDOP, SGY), rather than with standard P, T, K. This observation potentially has implications for theories of English phonology as well as of language and literacy acquisition. Understanding these implications, however, requires…

Reports on the development of a test of phonemic awareness suitable for administration to young children. Compares kindergarteners' performance on a measure controlling for global similarity and another measure not controlled. Finds support for the importance of controlling for global similarity when attempting to measure phoneme invariance. (RS)