Proceedings of the Annual Meeting of the Cognitive Science Society

Although most U.S. children can count sets by 3.5 years of age, many fail to understand that adding 1 to a set correspondsto counting up 1 word in the count list (i.e., the successor function). Initially, children have piecemeal knowledge of thisrelation, and do not understand that it holds for any number. Although generalized successor knowledge emerges around6 years of age, it is unknown when children’s item-based learning begins, and therefore when they begin learning relationsbetween number words – a critical precursor to mathematical reasoning. Here, we explore the timescale and mechanismsunderlying this knowledge in 2- to 4-year-old children. We find that these children have established item-based mappings,but that they are unrelated to count list knowledge. Instead, we show evidence that the origins of successor knowledgemay lie in mappings made between non-symbolic set representations and known number words.