Psychological foundations of number: numerical competence in human infants.

An enduring question in philosophy and psychology is that of how we come to possess knowledge of number. Here I review research suggesting that the capacity to represent and reason about number is part of the inherent structure of the human mind. In the first few months of life, human infants can enumerate sets of entities and perform numerical computations. One proposal is that these abilities arise from general cognitive capacities not specific to number. I argue that the body of data supports a very different proposal: humans possess a specialized mental mechanism for number, one which we share with other species and which has evolved through natural selection. This mechanism is inherently restricted in the kinds of numerical knowledge it can support, leading to some striking limitations to early competence.