1. 1 Number Development: Debate “Can infants add and subtract?”

2. 2 Arguments in Support 1.Infants dishabituate in a manner that suggests the ability to operate on number (addition and subtraction) 2.Converging findings come from studies using different methodologies. These rule out: e.g., Explanations in terms of preferences for spatial locations e.g., Explanations in terms of preferences for spatial locations

3. 3 Arguments Against 1.Not always replicated and small effects 2.Occam’s razor: Preference for a familiar amount is a simpler account for early addition and subtraction 3.Preferences for many items could also account for the findings 4.This could be grounded in children’s early understanding of object permanence

4. 4 Notes of Caution Careful to distinguish between: Evidence supporting early representation of number Evidence supporting early representation of number Evidence supporting early operations on number Evidence supporting early operations on number

5. 5 Notes of Caution Great initial attempts to summarise the arguments. Continue to evaluate the arguments: Theoretical positions? Theoretical positions? Faults in experimental design? Faults in experimental design? Alternative explanations? Alternative explanations?

6. 6 Key references for addition/subtraction Neo-nativist Neo-nativist Karen Wynn’s account: Wynn, K. (1992). Addition and subtraction by human infants. Nature, 358, 749-750. Neo-piagetian/constructivist Neo-piagetian/constructivist Les Cohen’s account: Cohen, L. B. & Marks, K. S. (2002). How infants process addition and subtraction events. Developmental Science, 5, 186-201.