The relative salience of numerical and non-numerical dimensions shifts over development: A re-analysis of

Visual displays of objects include information about number and other magnitudes such as cumulative surface area. Despite the confluence of cues, a prevalent view is that number is uniquely salient within multidimensional stimuli. Consistent with this view, Tomlinson et al. (2020) report that, in addition to greater acuity for number than area among both children and adults, number biases area judgments more than the reverse, at least in childhood. However, a failure to consider perceived area, undermines these results. To address this concern, we used an index of perceived area when assessing acuity and bias of number and area. In this context, number and area were comparable in acuity among children and adults. Bias, however, differed across development. Although adults showed greater bias of number on area judgments than the reverse, children experienced greater area bias on number judgments. Thus, contra Tomlinson et al., when differences in mathematical and perceived area are accounted for, area is more salient than number early in development. However, number does become the more salient dimension by adulthood, suggesting a role for experience with symbolic number and education in directing attention towards number within multidimensional visual stimuli.