Genetic and environmental influences on aspects of literacy and language in early childhood: Continuity and change from preschool to Grade 2

Abstract

Early literacy and language skills of twin children in the USA, Australia, and Scandinavia were explored in a genetically sensitive design (maximum N = 615 pairs). For this article, we report aspects of preschool and Grade 2 data. In Grade 2, there were strong genetic influences on word reading, reading comprehension, and spelling. Vocabulary was about equally affected by genes and shared environment. Multivariate analyses indicated substantial genetic overlap among the Grade 2 literacy variables. Longitudinal analyses showed that genetic factors evident at the preschool stage continued to affect literacy and vocabulary three years later in Grade 2, but there was also evidence of new genetic factors coming into play over the time interval, at least for literacy. Suggestions are made about the search for underlying biological and cognitive processes, and educational implications are explored.

How Does Parental Reading Influence Children’s Reading? A Study of Cognitive Mediation

“…The corollary is that reading is genetically partly distinct from PA and RAN. These new genetic influences kick in after the start of formal reading instruction (Byrne et al, 2009). A partly unique aetiology of reading contradicts a strong endophenotype hypothesis with complete mediation.…”

Rethinking Sound : Computer-assisted reading intervention with a phonics approach for deaf and hard of hearing children using cochlear implants or hearing aids

“…In sum, the analogy between language and reading acqusition is, that both 35 abilities start out on larger units and gradually, through development, enable the processing of smaller units, in a more refined and detailed manner. In skilled reading, language (that is, phonological, morphological, semantic-syntactic and pragmatic competence) and visual processing (that is, the formation of abstract letter and orthographic representations) are used flexibly to derive meaning from print (Bavelier, Green & Seidenberg, 2013;Bitan, Manor, Morocz & Karni, 2005;Bjaalid, Høien & Lundberg, 1997;Byrne, Coventry, Olson et al, 2009;Castles et al, 2009;Rastle, 2007). Thus, the reader must both be able to do analytical, detailed translational work to decode unfamiliar words, as well as have a large enough orthographic lexicon that makes immediate, instant recognition of words possible (see dualroute models of reading, Stanovich, 2000).…”

“…The letter knowledge tasks were used in all four studies. Byrne et al, 2009) was used to assess decoding of real words and decoding of nonwords. Both measures were used in Study III.…”

“…Additionally, nonword decoding errors were categorized in four categories; phoneme insertions, phoneme deletions, phoneme substitutions, and lexicalization, that is, making a real word of the target nonword (Woodcock 1987; Swedish version by Byrne et al, 2009) was used to assess reading comprehension in Study III. This test uses a cloze procedure to assess the child's ability to understand passages of connected text.…”

“…In the nonword-decoding task (TOWRE; Torgesen, Wagner & Rashotte, 1999, Swedish version by Byrne, 2009) additional levels of analyses were entered. These were, per cent phonemes correctly decoded and four categories of children's decoding errors: phoneme insertions, phoneme deletions, phoneme substitutions and lexicalisations.…”