STRUCTURAL ALIGNMENT IN COMPARISON - NO DIFFERENCE WITHOUT SIMILARITY

Theories of similarity generally agree that the similarity of a pair i ncreases with its commonalities and decreases with its differences. Re cent research suggests that this comparison process involves an alignm ent of structured representations yielding commonalities, differences related to the commonalities, and differences unrelated to the commona lities. One counter intuitive prediction of this view is that it shoul d be easier to find the differences between pairs of similar items tha n to find the differences between pairs of dissimilar items. This pred iction is particularly strong for differences that are related to the commonalities. We tested this prediction in two experiments in which s ubjects listed a single difference for each of a number of word pairs. The results are consistent with the predictions of structural alignme nt. In light of these findings, we discuss the potential role of struc tural alignment in other cognitive processes that involve comparisons.