The role of part-whole information in reasoning about relative size

Models of comparative judgment have assumed that relative magnitude is comp uted from knowledge about absolute magnitude rather than retrieved directly . In Experiment 1, participants verified the relative size of part-whole pa irs (e.g., tree-leaf) and unrelated controls (e.g., tree-penny). The symbol ic distance effect was much smaller for part-whole pairs than for unrelated controls. In two subsequent experiments, participants determined either wh ich of two objects was closer in size to a third object or which of two pai rs had a greater difference in the size of its constituents. In contrast to the paired comparison task in Experiment 1, judgments of part-whole items were more sensitive to the influence of symbolic distance than were unrelat ed controls. The fact that the part-whole relation attenuates the effects o f symbolic distance in a paired comparison task but not in tasks that requi re an explicit comparison of size differences suggests that the part-whole relation provides a source of information about relative magnitude that doe s not depend on knowledge about absolute magnitude.