Examining the genetic and environmental associations among spelling, reading fluency, reading comprehension and a high stakes reading test in a combined sample of third and fourth grade students

• Our study extends investigations of the relations between reading fluency, spelling and reading comprehension skills
• This investigation is the first to examine the etiological influences on reading fluency, spelling and reading comprehension
• Our investigation explores the underlying etiology of state standardized assessments aligned with the Common Core initiative
• Our study includes a large and diverse sample of twins

The present study is an examination of the genetic and environmental effects on the associations among reading fluency, spelling and earlier reading comprehension on a later reading comprehension outcome (FCAT) in a combined sample of 3rd and 4th grade students using data from the 2011–2012 school year of the Florida Twin project on Reading (Taylor et al., 2013). A genetically sensitive model was applied to the data with results indicating a common genetic component among all four measures, along with shared and non-shared environmental influences common between reading fluency, spelling and FCAT.