Social and socio-
Ontogeny and symbolism
Symbols and structures in language acquisition
Carolyn Johnson, Henry Davis, and Marlys Macken
Children learning natural languages need to master a symbol system with both a constituent and a combinatorial structure. There are at present three main schools of theorizing as to how this mastery is accomplished: the 'interactive', which locates language-learning within its context of use; the 'cognitive', which locates language-learning as part of symbolic development in general; and the 'autonomous', which emphasizes the independence of the study of grammatical competence from both language use and general principles of cognitive development. Additionally, the task of language-learning is generally investigated under a number of independent headings: phonological acquisition; lexical acquisition; morphological and syntactic acquisition; and pragmatic acquisition.
The phonological (sound) system of a language is rule-based. Very young human infants can discriminate the majority of the features which comprise the adult sound system, and can do so across complex physical dimensions. At a minimum, infants' abilities provide an initial grid for segmenting, sorting, and classifying phonetic categories, and for mapping these to the higher levels of phonological systems. For production, there is continuity from the babbling period into early language. The early productive sound systems appear to be based on words rather than smaller units, words not being initially analysed into their component phonemes. This analysis begins between the ages of two and four years, although the child's system still remains simplified compared to that of the adult. The process of phonological development follows no invariant sequence, and can show regressions at the same time as the system becomes more complex. Some form of 'cognitive' theory at present provides the best explanatory framework
Verbal communication is preceded by gestural communication,
beginning at about nine months of age. Accounts have been
offered in which gestural communication is claimed to be
necessary for later language development, and continuous with
it; but the evidence on both these points is equivocal.
Meaningful 'words' are used from about one year of age. There
is a spurt in vocabulary development from around eighteen
months. Errors in word use provide the major data source for
theories of semantic development. These data have formed the
basis of a number of theoretical accounts; but none of these
are yet comprehensive in their explanatory powers. Crucially
lacking is an account of how the child learns to relate words
to concepts, and clear criteria for determining when a child's
'words' are truly symbolic.
Early functions of language are of three types: solicitation of action, social interaction, and joint attention; expression of affect; and participation in games. With the advent of naming, children can also label and request labels. Later developments, such as threatening, promising, and deceiving, have not been systematically studied.
The best-supported theories of language development are of the
'autonomous' school. It appears that language-learning skills
are domain-specific, and there are few parallels with
non-linguistic domains, or precursors to the formal systems.
Thus, the autonomous view presents difficulties for both onto-
and phylogenic accounts, in that it is a discontinuity view.
However, the 'interactive' and 'cognitive' schools at present
offer less plausible accounts of the acquisition of linguistic
abilities than 'autonomous' ones, even though they offer more
continuous views of development, and hence might be more
attractive to an evolutionary scenario at first sight