Mussolin, C. 1 , Hoffmann, D. 2 , Schiltz, C. 2 , Leybaert, J. 1 & Content, A. 1
1 Laboratoire Cognition, Langage et Développement, Université libre de Bruxelles, avenue F.D. Roosevelt 50, B-1050 Brussels, Belgium
2 Educational Measurements and Applied Cognitive Science Department, University of Luxembourg, L-7201 Luxembourg
Numerosity, area surface, and duration are fundamental information along which living species perceive and represent the world. Whether these dimensions are subtended by a common system of quantities is still open. Here we found no evidence for such a link in children aged from 4 to 7 years. Kindergartners and first grade children were presented with two successive sets of wagons one to the left and one to the right of the screen. Depending on the task, they had to judge either the numerosity (selecting the train with the more numerous wagons), the area surface (selecting the longest train), or the duration (selecting the train which “drives” for the longest time) by pressing the corresponding left or right button on a two-key pad. The ratio between the two members of each pair was manipulated for the relevant dimension. Participants successively performed the different ratios until accuracy felt below 70 percents. Performance on numerosity judgment was not correlated with performance on the two other judgments. The analysis of the highest ratio obtained by each child and the Weber fraction computed across all ratios indicated a finer representation for numerosity than area surface and duration in both kindergartners and first grade children.