Do infants understand simple arithmetic - a replication of Wynn (1992)

Numerical competence in 5-month-old infants is investigated using a violation-of-expectation paradigm. An experiment is reported which replicates the findings of Wynn (1992). In additional conditions, 5-month-olds are shown to be sensitive to impossible outcomes following addition or subtraction operations on small sets of objects, regardless of identity changes. Results support Wynn's interpretation that infants' responses are based on arithmetical ability. An alternative explanation, that infants' responses are based on their knowledge of the principles of physical object behavior, is also discussed.