The Development of Cardinal Extension: From Counting to Exact Equality

• DOI: 10.31234/osf.io/2agtm
• Publication Date: 2024-05-02T00:48:52Z
• Authors: Khuyen Nha Le; Rose M. Schneider; David Barner
• Keywords: Language Aquisition; Cognitive Development; Developmental Psychology; Social and Behavioral Sciences; Toddlerhood/Preschool Period

Numerate adults know that when two sets are equal they should be labeled by the same number word. We explored development of this principle - sometimes called ``cardinal extension'' and how it relates to children's other numerical abilities. Experiment 1 revealed 2- 5-year-old children who could accurately count large often inferred with word, unlike not sets. However, all counters made inference, suggesting learning construct label may a necessary but sufficient step in numbers represent exact quantities. 2 found extended labels were actually sensitive equality, also assigned approximately equal, differed just item (violating one-to-one correspondence). These results suggest gradual, stage-like, process which learn count, extend perceptually similar sets, then eventually restrict cardinal extension exactly equal.