Language handicaps. An interactive perspective

Language is the human hallmark par excellence . In normal circumstances, humans in any culture develop native languages that enable them to share virtually any kind of information with other native speakers. Even under adverse external conditions, as in the case of children raised in mixed-language or deaf communities, language arises as a communication system. In general terms, and from a phylogenetic perspective, humans can thus be seen as a species spontaneously establishing communication codes based on interchangeable, arbitrary symbols which can be combined to achieve meaning. Language is thus a natural tool—one that conveys the power to express one’s thoughts, to persuade, to argue or request actions— and language handicaps render individuals vulnerable to external manipulation. From an ontogenetic perspective, language can be seen as a life-long evolutionary process. After birth, the infant is normally immersed in the context of a speaking adult society where language-use is widely demonstrated to the infant. Although language is not explicitly taught, the infant is constantly hearing it. The process is extremely effective and results in a dramatic development of linguistic capacity in early childhood, a developmental process that proceeds throughout life, although at a less dramatic rate. Because the ground for language development is laid in early childhood, it is obviously important to be able to identify and treat at an early stage any children at risk of developing language disorders. It is in this context that the paper by Weindrich et al. in this issue of Acta Pædiatrica (1) is a very valuable contribution in the assessment of language abilities at ages 2 and 41⁄2 years in a large population of at-risk German children and in its attempt to identify factors that may signal the potential risk for language disorders. Weindrich et al.’s finding that psychosocial factors are better predictors of the child’s receptive capabilities than neonatal biological complications is a very important aspect, with far-reaching linguistic implications. Their results corroborate the notion that language is a highly interactive process unfolding through the interplay between the organism and its environment. And because they assess a population at risk, Weindrich et al. help shed new light on the linguistic debate concerning the nativist and functionalist developmental perspectives. In fact, in the 1960s and 1970s the language acquisition debate was dominated by the notion that an innate genetic programme containinga priori crucial linguistic information had been developed by the human species. We have confronted this position, recently vitalized by Steven Pinker in his book, The Language Instinct (2), with functionalist accounts of early language development in which language is viewed as a result of the on-line cumulative interaction between the organism and its environment (3, 4). The Weindrich et al. tudy clearly underlines the role of such interactional components as the psychosocial factors in language development, and seems to support the functionalist line of the present debate. Of particular relevance is the indication that parental level of education has a bearing on the level of eceptive language disorder by 2 years of age, which is in close agreement with findings from another population of children who required neonatal intensive care (5). An interesting aspect is that, from a linguistic point of view, parental education level on its own should not impact on the language acquisition process. It ought in fact to be irrelevant, because normal children in societies with low education standards nevertheless develop normal language. Why, then, should populations of infants at risk be affected by this factor? One possible reason is that the biological risk factors already present in these infants may enhance the child’s dependence on parental interaction. Since language development is a dynamic process, requiring fine-tuned adult − child interaction, the present results can be interpreted as suggesting that the less educated parents may be more sensitive to the coping difficulties that the infant’s biological problems clearly introduce. In this scenario, the normal adult −child interaction pattern may be disrupted, leading to less language input exposure and, in turn, to less developed receptive capacity. In general terms, this type of deficit may reflect a lack of experience with lexical items that would be familiar to children of that age. If other fundamental aspects of language, like syntax, have been grasped by the child, there should be a good recovery rognosis as the child gets more language experience. And this tendency does seem to occur, since incidence of deficits in receptive capacity diminishes greatly by 41⁄2 years of age. The other strong factor accounting for deficits in receptive language capacity by 2 years of life—parental psychiatric problems—further supports the notion that a prolonged lack of normal interaction may affect the child’s early linguistic performance. In this case, however, persistence of parental disorders may have a more long-term impact on the child’s recovery; this is suggested by the data in Weindrich et al.’s Table 2. Indeed, these results are compatible with recent experimental studies focusing on the infant’s capacity to organize Acta Pædiatr 87: 1213–8. 1998