Genetic and Environmental Influences on Word Recognition and Spelling Deficits as a Function of Age

Abstract

Previous twin studies have suggested a possible developmental dissociation between genetic influences on word recognition and spelling deficits, wherein genetic influence declined across age for word recognition, and increased for spelling recognition. The present study included two measures of word recognition (timed, untimed) and two measures of spelling (recognition, production) in younger and older twins. The heritability estimates for the two word recognition measures were .65 (timed) and .64 (untimed) in the younger group and .65 and .58 respectively in the older group. For spelling, the corresponding estimates were .57 (recognition) and .51 (production) in the younger group and .65 and .67 in the older group. Although these age group differences were not significant, the pattern of decline in heritability across age for reading and increase for spelling conformed to that predicted by the developmental dissociation hypothesis. However, the tests for an interaction between genetic influences on word recognition and spelling deficits as a function of age were not significant.

Gene–environment interaction on neural mechanisms of orthographic processing in Chinese children

“…As previous twin studies have emphasized the essential impact of both gene and environment on reading behavior (Bates, et al, 2004; Friend, et al, 2007; Gayán & Olson, 2003; Petrill, et al, 2010), a critical question is how these two factors interact. Two models have been proposed which outline the interaction mechanisms, until now.…”

“…Previous twin studies have examined the importance of both genetic and environmental influences on reading-related cognitive skills, such as phoneme awareness, spelling, and orthographic coding (Bates et al, 2004; Friend, DeFries, Wadsworth, & Olson, 2007; Gayán & Olson, 2003; Petrill et al, 2010). Among all the environmental factors, home literacy has been viewed as one of the most prominent predictors for reading disability (Grigorenko, 2001).…”

Children’s Educational Progress: Partitioning Family, School and Area Effects

“…The findings from these studies are presented in Table 1. This decomposition was often not the main focus of the paper in question and was presented as a preliminary to more complicated analysis, or in the discussion as an additional feature that could be calculated from the parameter estimates of a more complicated model (in Friend et al (2007) Spelling production 67 24 9 (wide range achievement test) Haworth et al (2007) Mathematics (teacher assessment) 68 9 23 Haworth et al (2008) Science (teacher assessment) 27 49 24 Petrill and Thompson (1993) Metropolitan achievement test 28 66 6 Petrill and Thompson (1994) Metropolitan achievement test 53 36 11 Thompson et al (1991) Mathematics 17 73 10 Thompson et al (1993) Composite of wide range 53 37 10 achievement test and metropolitan achievement test van den Oord and Rowe (1997) Peabody individual achievement test 60 16 24 Wainwright et al (2005) Queensland core skills test 67 19 14 †Where more than one response was examined in a study, we have selected just one to present here. some cases we performed this calculation ourselves to present the results here).…”

Genetic and environmental influences on the growth of early reading skills

“…At the same time, quantitative genetic studies have established the importance of both genetic and environmental influences on overall reading ability and disability (e.g., DeFries, Fulker, & LaBuda, 1987; Harlaar, Dale, & Plomin, 2007; Petrill, Deater‐Deckard, Thompson, DeThorne, & Schatschneider, 2006a; Samuelsson et al, 2008; Stevenson, Graham, Fredman, & McLoughlin, 1987), as well as on the skills that support reading ability, including vocabulary, print knowledge, phoneme awareness/decoding, spelling, and orthographic coding (e.g., Bates et al, 2004; Byrne et al, 2008; Friend, DeFries, Wadsworth, & Olson, 2007; Gayán, & Olson, 2003; Petrill, Deater‐Deckard, Thompson, DeThorne, & Schatschneider, 2006b). To date, behavioral genetic studies have focused on two issues related to reading development .…”