Inhibitory Control Predicts Growth in Irregular Word Reading: Evidence From a Large-Scale Longitudinal Study

Irregular words cannot be read correctly by decoding letters into sounds using the most common letter-sound mapping relations. They are difficult to read and learn. Cognitive models of word reading and development as well as empirical data suggest that inhibitory control might be important for irregular word reading and its development. The current study tested this in a U.K. population-based cohort (N = 529, 52.74% male, 90.17% White) in which children were assessed longitudinally at ages 5-6, 7-8, and 10-11 years. Results showed that inhibitory control did not predict concurrent irregular word reading after controlling for the covariates of decoding and vocabulary. However, inhibitory control made a small but significant contribution to growth in irregular word reading across time points, over and above vocabulary (decoding did not predict growth). Therefore, children might need to inhibit the predisposition to overgeneralize the most common relations between letters and sounds when learning to read irregular words. Public Significance Statement Our study suggests that children might need to inhibit the tendency to use the most common letter-sound mapping relations in order to develop their ability to read irregular words. Teachers may want to encourage students to think whether the pronunciation they generate for a written word matches a spoken word they know, and whether the spelling they generate for an oral vocabulary item matches the written form in print.