Proceedings of the Annual Meeting of the Cognitive Science Society

The developmental and evolutionary origins of abstract number reasoning have long been debated. Central to this debate is the underlying unit: whether the quantitative reasoning observed in infants and animals necessitates truly numeric object-level representation or can instead be inferred from covarying low-level spatial frequency. Recent studies with adults rely on the "connectedness illusion" to dissociate cardinality from spatial frequency, suggesting object-level representation is fundamental. However, whether these representations exist early in development remains underexplored. We use the connectedness illusion to test whether 3–6-year-old children enumerate objects or spatial frequency. Children complete a non-symbolic comparison task modeled after He et al. (2009). On 50% of trials, two dots are connected by a line, forming a "barbell." Results show that, like adults, children underestimate connected displays despite instructions to ignore the connections. These findings suggest that object-level representations, rather than low-level spatial frequency, underlie children's quantitative reasoning.