Executive Function and Language Expression in Preschool Children: A Random Intercept Cross-Lagged Panel Study.

This study examined longitudinal between-child and within-child associations between executive function (EF) and language expression (LE) in preschool children. Data were drawn from four waves of the Kids in Taiwan: National Longitudinal Study of Child Development and Care at 36, 48, 60, and 72 months (N = 1694). Longitudinal measurement invariance was examined before estimating a random intercept cross-lagged panel model (RI-CLPM), which separated stable between-child differences from within-child temporal fluctuations. EF and LE showed temporal continuity and positive concurrent associations. At the within-child level, occasions on which children displayed stronger LE than their own typical level consistently preceded relatively stronger EF one year later, whereas the reverse pathway was not consistently supported. These findings refine language-based accounts of self-regulation by suggesting that children's everyday use of language to answer, explain, clarify, and organize information may be relevant to subsequent regulatory functioning. Practically, language-supported activities involving rule explanation, self-guidance, and reflective dialogue may be useful components of early EF support, although causal conclusions are not warranted from this observational study.