Are Rational Numbers Spontaneous? Natural Numbers Suffice all Processing by the Number Sense

The presence of preverbal numerical abilities in animals and infants is widely established, but an important discussion remains about which cognitive systems support these abilities. In particular, a great amount of research is dedicated to the approximate number system (ANS) for the elaboration of non-symbolic numbers and their possible types of mental numeric representations. In a recently published article, Clarke and Beck (2021) provide a series of evidence that supports its existence (ANS) and argue that the mental referents of this system are both natural and rational numbers. In the current commentary, we introduce the notion of the "whole-entity bias" that permeates perception and cognition and favors an automatic processing of discrete mental magnitudes while hindering the representations of fractional numbers. Further, we argue that a hierarchical structure of the ANS that represents natural numbers and supports the understanding of proportions through a series of computations is a more ecological theorization. To conclude, we believe that such a view is still compatible with the proposal of a single representational system (the ANS) supporting both number kinds but offers a different perspective on the computational level of explanation.