The development of diachronic thinking: 8–12‐year‐old children's understanding of the evolution of forest disease

Very little is known about the use children make of temporal concepts in their explanations of reality. The experiment presented here concerns the development of diachronic thinking in children, i.e. their ability to situate an object of knowledge along a temporal dimension and to conceive changes of this object over time. The experimental situation concerns forest disease and explores the child's ability to understand this phenomenon and to reconstruct the stages of its evolution. A total of 52 children aged from 8 to 11 years were asked questions about the past and future states of a diseased tree. The results show that important changes take place between 8 and 11 years in the conception of the evolution involved and reveal the components of a diachronic perspective. This perspective does not only consist of imagining and ordering steps in an evolutive process. It must also include the ability to establish a link between the steps by conceiving internal transformations that produce external changes. The changes constitute a continuous and gradual sequence, going from past to future. This diachronic perspective is not completely mastered before the age of 10–11 years. Before this, children have a punctual representation, imagine a small number of steps, a short time span and do not establish links between past and future.