Where does the stone go when we drop it? Development of French schoolchildren’s knowledge of gravity

In this study, we explored children’s knowledge of gravity at different ages (5–6, 7–8, and 9–10 years), by asking the same question (“Where does a stone go when we drop it?”) in three different contexts (on Earth, in a spaceship orbiting the Earth, and on the Moon). We tested the influence of context and children’s age on both the answers and the justifications they provided. We expected that children of all ages would find it easier to make correct predictions in the Earth context than in the other two contexts. We were also interested in the kinds of justification children construct and how these justifications change during ontogenesis. Seventy-two French children were individually interviewed at their school. None of them had received any direct teaching about gravity. Results showed that children found it easier to predict the fall of the stone on Earth than its behaviour in the other two contexts, but that the younger children predicted the fall of the stone on the Moon more accurately than the older children. This unusual developmental effect only occurred for the Moon context. We also found that the categories of justifications changed with age, with a move away from intuitive considerations towards mechanistic ones.