ABSTRACT
Capacity has proved a difficult and controversial topic, in both cognition and cognitive development. The question of whether processing capacity changes with age has been particularly intractable in cognitive development, and for approximately three decades there have been two, apparently irreconcilable, schools of thought. Some theorists have proposed that growth in processing capacity or efficiency is a factor that has a major explanatory role in cognitive development (Case, 1985; Halford, 1993; McLaughlin, 1963; Pascual-Leone, 1970). There is no suggestion that capacity carries the whole explanatory burden, but that it is an enabling factor that interacts with knowledge acquisition through experience. Other theorists have argued that growth in capacity has no role in cognitive development, and place the whole explanatory burden on acquisition and organisation of knowledge (Carey, 1985; Chi & Ceci, 1987).
