Inhibitory control and the understanding of buoyancy from childhood to adulthood

Intuitive conceptions represent common obstacles to conceptual learning in science. A growing number of studies demonstrate that when learning occurs, these intuitive conceptions are not replaced by scientific conceptions but rather coexist with them and thus need to be inhibited to prevent systematic errors. However, to date no study has demonstrated that the increasing ability to mobilize a given scientific conception is rooted in the increasing ability to inhibit the intuitive conception that interferes with it. In the current study, we investigated whether the increasing ability from childhood to adulthood to solve a scientific problem regarding the buoyancy of marbles of different sizes and densities is rooted in the increasing ability to inhibit the "bigger objects sink more" intuitive conception. To do so, we designed a negative priming paradigm in which 11-year-old children, 17-year-old adolescents, and 24-year-old adults were asked to choose which of two marbles of various sizes and densities sinks more. Negative priming effects reported in children and adolescents suggest that, unlike adults, they must inhibit the "bigger objects sink more" intuitive conception to determine, for instance, that a small marble with high density (e.g., small lead marble) will sink more than a bigger marble with a lower density (e.g., big wooden marble). We also found that the amplitude of negative priming effects decreased with age, suggesting that the level of exposition to the scientific knowledge of buoyancy (increasing with age) may decrease the need to inhibit the "bigger objects sink more" intuitive conception.