Change and continuity in early spatial development: Claiming the "radical middle"

Debate over change and continuity in cognitive development has revolved aro und questions of qualitative transitions versus quantitative and incrementa l improvement. Piaget's stage theory is the best-known example of a change/ qualitative transition approach, while both nativism and empiricism have, f or very different reasons, taken a continuity/quantitative increment stance . Recent proposals have, however, attempted to transcend this stark dichoto my, in a move that can be termed claiming the "radical middle." This paper presents two examples of developmental analyses in spatial development. The se two transitions are characterizable as either qualitative or quantitativ e, but are best thought of as both. A position of this kind allows for much more precise answers to practical questions about issues such as sensitive periods than would otherwise be possible.