Background
The present study aimed to examine the early growth of word and nonword reading fluency and their cognitive predictors in a consistent syllabic orthography (Japanese Hiragana).
Method
One hundred sixty‐nine Grade 1 Japanese children (Mage = 80.12 months, SD = 3.62) were followed until the middle of Grade 2 and assessed four times on word and nonword reading fluency in Hiragana. Nonverbal IQ, vocabulary, phonological awareness, rapid automatized naming, phonological memory and morphological awareness were also assessed at the beginning of Grade 1.
Results
Growth curve analysis showed that growth was faster in word reading than in nonword reading and the lexicality effect increased over time. Rapid automatized naming, phonological memory and morphological awareness were associated with the initial status and rate of growth in word and nonword reading. Furthermore, the initial status and the growth rates were highly correlated between word and nonword reading, even when the effects of the cognitive skills were controlled.
Conclusions
These findings suggest that, despite the remarkable differences in the growth trajectories of word and nonword reading fluency, they share at least a part of their underlying processes and develop closely in tandem during this period.