Is diachronic thought a specific reasoning ability? 1The authors are grateful to Fawzia Campana, Florence Dokic, Stéphanie Jaccard, Rachel Luternauer, Isabelle Maeder, Delphine Rinaldi and Lise Rubin for their important help during the collection and analysis of the data. They also wish to thank the children who participated in the experiment and their teachers for their cooperation.

Abstract

Several experiments have shown that cognitive abilities involved in the representation and understanding of change over time (what we term “diachronic thought”) develop strikingly in various domains between the ages of 8 and 12 years. Do these abilities simply reflect the child's general cognitive level or are they specific reasoning competencies related to change over time? The present research deals with this question and studies the relationships between three tasks assessing diachronic thought (Qualitative transformation, Temporal dissociation and Dynamic synthesis) and two tasks assessing the children's operatory level (Probabilistic reasoning and Spatial reasoning). Each set of tasks was presented during a separate session to 45 children aged 8, 10 and 12 years. As expected, a significant development in the subjects' answers to diachronic and operatory tasks was observed. Moreover, the results revealed that there was a significant correlation between two diachronic tasks and the operatory tasks as long as the effect of age was not controlled, but that only the correlation between tasks in the same set (either diachronic or operatory) remained significant when the age effect was controlled. We interpret these results as showing that diachronic thought, as assessed with our three tasks, can be considered as a specific reasoning ability.