The Component Processes of Complex Planning Follow Distinct Developmental Trajectories

This study aimed to distinguish between the developmental trajectories of different cognitive component processes underlying planning decisions. Participants (8-25 year olds) completed a planning task called Four-in-a-row. By fitting a computational model, we distinguished between three cognitive component processes of planning: planning depth, heuristic quality, and attentional oversights. All three contributed to better playing strength, but they differed in their developmental trajectories. Specifically, from early to mid-adolescence, heuristic quality rapidly improved and contributed to better playing strength. From mid to late-adolescence, planning depth increased and supported better playing strength. Fewer attentional oversights were associated with better playing strength and this relation did not show age differences. Together, these results suggest an order in which the use of cognitive component processes of planning develop, starting by first refining the heuristic strategies, then gradually increasing the number possible future actions, states, and outcomes considered towards young adulthood. The findings move the field of cognitive development towards a more complete account of the development of planning and its component processes.