Two-year-olds' executive functioning: The influence of task-specific vocabulary knowledge.

Although many executive function (EF) tasks require only nonverbal responses, the language used by experimenters to explain the task may be important for young children's EF task performance. This study investigated how the vocabulary used in explaining an EF task affects 2-year-olds' performance. Experiment 1 used the standard instructions for the Reverse Categorization Task, in which children are asked to sort different-sized blocks into different-sized buckets according to one rule and then switch to a new rule. In Experiment 2, the task remained the same, but different instructions requiring less knowledge of size words were used. Children's productive vocabulary was assessed in both experiments but was only correlated with task performance in Experiment 1. These results suggest that task-specific vocabulary knowledge may play a role in children's performance on tasks designed to measure nonverbal cognitive ability.