Learning sameness: object and relational similarity across species

• Published in: Current opinion in behavioral sciences 2021-02, Vol.37, p.41-46
• Main Author: Christie, Stella
• Format: Article
• Language: English
• ISSN: 2352-1546; 2352-1554
• DOI: 10.1016/j.cobeha.2020.06.010

•Perception of relational similarity underlies fundamental cognitive abilities.•Relational abstraction is partly learned through perception of object similarity.•Human children favor object over relational similarity while animals do not.•Animals abstract relations better from dissimilar objects.•Too little or too much variation among objects dampens human relational abstraction. Humans’ impressive cognitive abilities — map reading, understanding numerical structure, learning grammar rules — rest on the ability to abstract sameness of relations. How does this ability arise and why do animals not read maps or learn grammars like humans do? Here, I review evidence suggesting that object similarity — perceiving that two events look alike — is crucial for learning to perceive relational similarity. While both humans and nonhuman animals perceive object similarity, species differ in their initial preference for objects relative to relations and in their learning trajectories. Human children spontaneously prefer object over relational similarity and this preference benefits their relational reasoning; animals do not favor object similarity. For animals, relational abstraction is easier when the underlying objects are dissimilar, but in humans this relationship is concave.