Vocabulary and Executive Functioning: A Scoping Review of the Unidirectional and Bidirectional Associations across Early Childhood.

Early childhood marks a time where word learning is accompanied by rapid growth in the cognitive processes that underlie self-modulated and goal-directed behavior (i.e., executive functions). Although there is empirical evidence to support the association between executive functioning and vocabulary in childhood, inconsistent findings have been reported regarding the extent to which early executive functioning abilities predict later vocabulary outcomes and vice versa. To clarify the nature of the longitudinal relation between these two processes and to examine what, if any, claims can be made about their interdependence, a critical review of the literature was conducted. Also addressed are the conceptual and/or methodological differences that exist across studies conducted on this topic that may be contributing to some of the discrepancies reported in the longitudinal literature. Finally, this review provides practical and empirically informed future directions to serve as a resource for early childhood researchers advancing this area of study.