Planning ahead: goal-directed problem solving by 2-year-olds.

On tasks that require overcoming an obstacle along an existing path to a physically present goal, infants and very young children evince planning. In each of 3 experiments, the authors tested 21- and 27-month-olds' ability to construct a path to a mentally re-presented goal. Across experiments, the authors varied the number and type of cues to the solution provided. After exposure to the goal-state configuration of problems, both age groups showed evidence of planning (Experiment 1). Demonstration of the initial step in the solution path in Experiment 2 was not as effective as exposure to the goal state in Experiment 1. Even with specification of a greater proportion of the goal path, goal-state configuration information was particularly effective in facilitating performance (Experiment 3). The results suggest productive generation of solutions to novel problems by young children; planning is facilitated by goal-state configuration information.