Heterotypic continuity of inhibitory control in early childhood: Evidence from four widely used measures.

Inhibitory control has been widely studied in association with social and academic adjustment. However, prior studies have generally overlooked the potential heterotypic continuity of inhibitory control and how this could affect assessment and understanding of its development. In the present study, we systematically considered heterotypic continuity in four well-established measures of inhibitory control, testing two competing hypotheses: (a) the manifestation of inhibitory control coheres within and across time in consistent, relatively simple ways, consistent with homotypic continuity. Alternatively, (b) with developmental growth, inhibitory control manifests in more complex ways with changes across development, consistent with heterotypic continuity. We also explored differences in inhibitory control as a function of the child’s sex, language ability, and the family’s socioeconomic status. Children (N = 513) were studied longitudinally at 30, 36, and 42 months of age. Changes in the patterns of associations within and among inhibitory control measures across ages suggest that the measures’ meanings change with age, the construct manifests differently across development, and, therefore, that the construct shows heterotypic continuity. We argue that the heterotypic continuity of inhibitory control motivates the use of different combinations of inhibitory control indexes at different points in development in future research to improve validity. Confirmatory factors and growth curves also suggest that individual differences in inhibitory control endure, with convergence among inhibitory control measures by 36 months of age