(Copyright © 2000 Piero Scaruffi | Legal restrictions - Termini d'uso )
Modern studies severely undermine Piaget's model of cognitive development. In particular, Piaget's theory is inadequate to explain how children learn language. Without any a-priori knowledge of language, it would be terribly difficult to learn the theory of language that any child learns.
The British psychologist Annette Karmiloff-Smith, a student of Piaget, has proposed a model of child development that bridges Fodor's nativism (built-in knowledge) and Piaget's constructivism (learning), i.e. innate capacities of the human mind and subsequent representational changes. Karmiloff-Smith envisions a mind that is both equipped with some innate capacities and that grows through a sequence of subsequent changes. Karmiloff-Smith's child is genetically pre-wired to absorb and organize information in an appropriate format. Each module develops independently, as proved by children who exhibit one mental disorder but are perfectly capable in other ways. Karmiloff-Smith's starting point is Fodor's model of the mind (that the mind is made of a number of independent, specialized modules), but, based on evidence of brain's plasticity (the brain can restructure itself to adapt to an early damage), Karmiloff-Smith believes that modules are not static and "grow" during child's development, and that new modules are created during child's development ("gradual modularization"). She points out that children display from the very beginning a whole array of cognitive skills, albeit still unrelated and specific (for example, identifying sounds, imitating other people's movements, recognizing the shapes of faces). Therefore, the child must be born with a set of pre-wired modules that account for these cognitive skills. Somehow, during development the modules start interacting and working together and adult life takes shape. Initially, children learn by instinct, or at least "implicitly". Then their thinking develops, and consists of redescribing the world from an implicit form to more and more explicit forms, to more and more verbal knowledge. Naturally, the environment that drives the mind's growth also includes the other individuals. Education and playing are forms of influencing the evolution of the thought system of a child. Karmiloff-Smith notes a thread that is common to several spheres of cognition: the passage from procedural non-expert to the automatic (nonprocedural) expert also involves a parallel passage from implicit to explicit knowledge (from executing mechanically to understanding how it works). Child development is not only about learning new procedures, it is about building theories of why those procedures do what they do. This "representational redescription" occurs through three stages: first the child learns to become a master of some activity; then she analyzes introspectively what she has learned; and, finally, she reconciles her performance with her introspection. At this point the child has created a "theory" of why things work the way they work. Therefore Karmiloff-Smith admits cognitive progress like Piaget, but her "representational redescription" occurs when the child has reached a stable state (mastery), whereas in Piaget's model progress only occurs when the child is in a state of disequilibrium. This process involves re-coding information from one representational format (the procedural one) to another (a quasi-linguistic format). There are therefore different levels at which knowledge is encoded (in contrast with Fodor's language of thought). The same "redescription" process operates within each module, but not necessarily at the same pace. In each field, children acquire domain-specific principles that augment the general-purpose principles (such as representational redescription) that guide their cognitive life. The cultural context determines which modules arise. Finally, mapping across domains is a fundamental achievement by the child's mind.
Five chapters describe how it works in five different spheres of mental activity. Karmiloff shows how children start with innate dispositions for language, achieve linguistic mastery and then develop metalinguistic knowledge through representational redescription. Analogously, the child masters the physical objects and later develops a naive Physics of her own (a theory of object behavior). Same applies to Mathematics and to Psychology (children develop a theory of mind that explains the behavior of other children). Karmiloff's model turns Piaget's theory on its head. As far as Fodor goes, Karmiloff qualifies the role of the central processor and the format of the language of thought (which turns out to be rather a set of languages). And knowledge can be used across domains.