Estimation of euclidean quantity by 5- and 6-year-old children: Facilitating a multiplication rule

Current findings indicate that 5- to 6-year-old children estimate the size of Euclidian objects by an addition rule of Height + Width. This is puzzling because the use of a multiplying rule should be a natural consequence of the perception of simple Euclidian objects. An attempt was made within the framework of information integration theory to test whether intensive handling (for 10 min) would facilitate a shift from the use of addition to multiplication. The stimuli included rectangles, triangles, liquid in glasses, and parallelopipeds. As predicted, following stimulus handling, subjects shifted from using an additive rule of integration to using a normative multiplicative rule.