Learning same and different relations: cross-species comparisons

Humans excel among species in abstract representation and reasoning. We argue that the ability to learn through analogical comparison, augmented by symbolic systems, underlies our cognitive advantage. The relations same and different are an ideal testbed for these ideas: they are fundamental, essential to abstract combinatorial thought, perceptually available, and studied extensively across species. The evidence suggests that whereas a sense of similarity is widely shared across species, abstract representations of same and different are not. We make three key claims, First, analogical comparison is critical in enabling relational learning among humans. Second, relational symbols support forming and retaining same and different relations in both humans and chimpanzees. Third, despite differences in degree of relational ability, humans and chimpanzees show significant parallels in the development of relational insight.