Developing an intuitive understanding of conservation and contamination: Invisible particles as a plausible mechanism.

Abstract

Four studies examined whether 3- to 7-year-olds appreciate that a substance can continue to exist and maintain its inherent properties (e.g., taste, having weight) even after it has become invisible upon dissolution. These studies also examined whether young children have the concept of «tiny, invisible particles» and if so, whether they can use it to reason about material kinds. These studies revealed that, by age 3, some children could appreciate both conservation of matter despite visual disappearance and the existence of tiny, invisible particles. Moreover, they could make use of the particle concept to come up with a plausible mechanism for how a substance can continue to exist and maintain its inherent properties despite visual disappearance upon dissolution. The proportion of children who could do so increases with age