Although labeling improves executive function (EF) performance in children older than 3 years, the results from studies with younger children have been equivocal. In the current study, we assessed performance in a computerized multistep multilocation search task with older 2-year-olds. The correct search location was either (a) not marked by a…

Age-appropriate modifications of the A-not-B task were used to examine 2-year-olds' search behavior. Several theories predict that A-not-B errors will increase as a function of number of A trials. However, the hierarchical competing systems model (Marcovitch & Zelazo, 1999) predicts that although the ratio of perseverative to nonperseverative…

Meta-analysis of the A-not-B error was conducted, using logistic regression, on studies conducted before September 1997. Results replicated earlier findings, with exception that the number of trials at the A location was a significant predictor, and the number of locations was a significant predictor of the proportion of infants who searched…