Young children's attention to global magnitude: evidence from classification tasks.

Young children often compare objects holistically and not in terms of separate dimensions such as size and color. One holistic relation that often governs young children's object comparisons is overall similarity. Two experiments were conducted to examine the possibility that a holistic magnitude relation might also govern children's object comparisons. Objects varying on two dimensions of magnitude-size and saturation--were classified by 3-, 4-, and 5-year-olds. The results indicated that the younger children were sensitive to global magnitude as well as overall similarity. They grouped together large and saturated objects or small and desaturated objects more often than they did large and desaturated (or small and saturated) objects and thus appear to have been classifying by combined magnitude across both dimensions. This new finding that young children classify by a global relation of magnitude refines the understanding of perceptual development and provides information about the structure of perception. Young children's use of global magnitudes in classification also fits well with recent findings about children's acquisitions of dimension words.