The developmental stability of inhibition from 2 to 5 years.

Executive functions or cognitive self-regulatory control processes are critical for children's ability to successfully navigate their academic and social environment. In this study, we focused on the development of one critical executive function skill, that of inhibitory control. In a longitudinal study, we tested 96 children at 24, 30, 36, 50, and 60 months of age with age-appropriate measures of inhibition. We found evidence for the developmental stability of inhibitory abilities. Inhibitory control at 30 months of age was strongly related to inhibitory control at 60 months of age even when verbal IQ was partialled out. Statement of contribution What is already known on this subject? Prior research has shown that executive functions play a key role in children's academic as well as social development. However, evidence on the stability of individual differences in executive functions, especially in preschool children, is sparse and contradictory. What the present study adds? The present work was designed to investigate the stability of one particular executive function, namely inhibitory control, over a relatively large period of time, from 24 to 60 months of age. The most important finding is a robust correlation between Reverse Categorization at 30 months and Simon Says at 60 months (r = .56). We argue that this further highlights the importance of early EF interventions due to a possible 'ripple effect'.