Children’s understanding of curvilinear downward motion

Previous recent work has outlined that throughout middle childhood the ability to integrate knowledge about horizontal and vertical motion dimensions in order to reason about motion down inclines appears to change with increasing age. To investigate this shift in more detail, this study investigated children’s understanding of motion down curved slopes by addressing the changing interaction of horizontal and vertical dimensions along a single trajectory. Across four different age groups children were asked to predict motions of balls down curved tubes by addressing both comparisons between balls (heavy and light) and between sections of the trajectory (shallow incline, intermediate incline, steep incline). The results suggest that children do integrate information from horizontal and fall when judging motion down inclines. Crucially, this integration changes with increasing age, implying a change in salience of support in the process of motion reasoning and the overall development of commonsense theories of motion. Potential implications for educational practice are discussed.