Theoretical perspectives on language and communication problems in mental retardation and developmental disabilities

We argue that researchers interested in language and communication problems in mental retardation or any other developmental disorder should view such problems as emerging within the broader context of the behavioral profile, or phenotype, associated with a particular genetic condition. This will re quire understanding the direct and indirect effects of genes on the develop ment of language and communication and thereby an understanding of the comp lex relations that exist between language and other dimensions of psycholog ical and behavioral functioning as well as an understanding of the environm ents in which the developing person acts and is acted upon. We believe that the dominant model for understanding language and communication problems-t he nativist approach, which emphasizes the child's innate capacity for acqu iring language and characterizes language as consisting of a set of context -free deterministic rules that operate on abstract representations-is incon sistent with an emphasis on indirect genetic effects. We review recent evid ence that undermines the nativist approach-evidence concerning the initial state of the language-learning child, the role of environmental input, the competence-performance distinction, and modularity. in place of nativism, w e argue for Emergentism, which is a model in which language is seen to emer ge from the interaction between the child's biological abilities to map sta tistical properties of the language input into a distributed representation and the characteristics of the language learning environment and for the p urpose of engaging in real-time, meaningful language use. (C) 2001 Wiley-Li ss, Inc.