Do Young Children Understand Conservation of Number?

Abstract

HALFORD, GRAEME S., and BOYLE, FRANCES M. Do Young Children Understand Conservation of Number? CHILD DEVELOPMENT, 1985, 56, 165-176. Children were shown displays that were neutral in that, taken individually, they always elicited chance judgments of number. The first display was transformed into the second, then into the third, and so on. Although children would be equally likely to judge either way on any one display, it was reasoned that if they understood conservation their pretransformation judgments would influence their posttransformation judgments. Without understanding of conservation, successive judgments would be independent of each other. It was found that 3-4-year-olds' judgments were independent, showing no recognition of invariance at all, whereas 6-7-year-olds' judgments were significantly more consistent than would be expected by chance. In the second experiment, judgments following transformations were contrasted with a control condition without transformations. The 3-4-year-olds showed consistency in the control condition, but not in the transformation condition. In Experiment 3 an accidental transformation was used, and in Experiment 4 judgments were permitted, but 3-4-year-olds still failed to show consistency. In Experiment 5 same judgments were permitted in tests where young children had succeeded with more/less judgments, and 3-4-year-olds failed to show conservation. It was concluded that 3-4-year-old children do not understand conservation of number.