Relationship Between Inhibitory Skills and Numerical Momentum in Infancy

Infants as young as 9 months demonstrate both inhibitory control, as revealed by the Spatial Negative Priming (SNP) effect, and numerical biases, such as the Operational Momentum (OM) effect–an overestimation in addition and underestimation in subtraction. Despite their early and parallel emergence, no studies have investigated whether these two cognitive abilities are related in infancy. In the present study, we tested 9- and 12-month-old infants in Paris on both a SNP task, measuring inhibitory skills, and an OM task, assessing sensitivity to directional biases in ordinal numerical sequences. Our results revealed a significant negative correlation between SNP and OM at 12 months, and between SNP at 9 months and OM at 12 months: infants with stronger inhibitory control showed reduced sensitivity to OM. These findings suggest that early inhibitory mechanisms may play a role in the development of OM bias during infancy.