Thematic integration in the similarity of abstract and concrete items

Thematic integration plays a role in similarity judgments of pairs of items that are unrelated taxonomically, like soup and spoon. We hypothesized that integration serves as a more central process in the similarity evaluation of abstract items because of their temporality, their large variability, and relational nature. Participants rated the similarity of concrete or abstract word pairs, followed by a written explanation of the ratings. Explanations were coded as thematic integration and taxonomic comparison. Consistent with our hypothesis, the rate of integration responses was higher overall for abstract items, and integration of abstract items occurred frequently even for item pairs for which taxonomic comparison was possible, unlike for concrete nouns.