Learning on the Balance Scale Task

Introduction The balance scale task has become a benchmark task in cognitive developmental psychology. Development on the balance scale task is characterized as a progression through a series of increasingly complex rules (Rule I, II, III, IV). Children using Rule IV understand the multiplicative relation between the two task features, weight and distance information of blocks placed at both sides of the fulcrum of a scale (Siegler, 1981). We study two possible answers to the question how children learn on the balance scale task. First, children may switch to a more complex rule because they start to perceive uninspected aspects of the scale (i.e., they start to notice the distance dimension). Second, children may switch as they acquire information that contrasts their old beliefs (i.e., observing that a scale tips to the side with the smaller number of blocks, placed at a larger distance). We focus on both the transition from Rule I (paying attention to the weight dimension only) to Rule II (paying attention to the distance dimension as well but only in case the numbers of blocks are equal) and the transition from Rule II to Rule III (always paying attention to both dimensions but ignorant of the correct combination). We assume that children using Rule I improve their ability to perceive distance when observing a series of items with an increasing difference between the distance at which the stack of blocks is placed on the left and the distance at which the stack of blocks in placed on the right side (see Figure 1). Children using Rule II may benefit from the presentation of so-called conflict items (both the distances and the weights differ; the largest number of blocks is placed at the smallest distance).