Science or Magic? Reactions of 5-Year-Old Pupils to a Counterintuitive Experiment

International audience; Testing the reproducibility of an experiment is considered a good practice in science, and the possibility to reproduce an experiment is a condition of its scientificity. We investigate the ability of children to consider a counterintuitive phenomenon as reproducible. The study involved 62 5-year-old children from 4 classes. They were presented with a bottle in which a hole had been pierced and asked if it was possible to stop the water from flowing through the hole without closing it. They were then shown that this result can be obtained by screwing the bottle’s cap. This experiment is counterintuitive enough to be used by some illusionists as a magic trick. It was explained to them that it happens because, since no air can enter the bottle, therefore no water can leave it. Individual interviews were realized by the children’s own teachers. The questionnaire involved questions about their understanding of the notion of reproducibility and the importance of testing reproducibility both by the child himself and by others.