Contents

Section 1
Palaeoanthropology


Photogallery

Outline of Human Phylogeny

Evolutionary Trees
and DNA


Brain Evolution

Hand and Bipedality

Section 2
Social and socio-
cultural systems


Primate societies

Social relations and the evolution of culture

Social relations, communication and cognition

Human socio-cultural patterns

Tools and symbolic behaviour

Palaeolithic Art

Contemporary hunter-gatherer art

Section 3
Ontogeny and symbolism


Editorial Introduction: Ontogeny & Phylogeny

The role of ontogenesis

Brain, cognition, and language

Early interaction and cognitive skills

Language and thought

Theories of symbolization
and development


Children's drawings and the evolution of art

Section 4
Language systems


Spoken language and
sign language


The gestural primacy hypothesis

Comparative cognition

Animal language and cognition

Language acquisition

Language
reconstruction


The prehistory of grammar

Writing systems

Links

Links Policy

Relevant Links

Symbols and structures in language acquisition


Carolyn Johnson, Henry Davis, and Marlys Macken


Abstract
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.

The acquisition of syntax can be divided into three stages: presyntactic; syntactic; and postsyntactic. Early presyntactic word-combinations are of three types: the combination of words that reflect grammatically relevant real-world relations; a word plus an intonationally integrated but meaningless extra syllable; and formulaic or rote-learned sequences. It is not clear whether there is any continuity between the combinatorial structures of this stage and those of the next, syntactic, stage, which lasts from about two to five years of age. First-language learners make very few errors in constructing complex grammars - a fact supporting the claim that there are innate constraints, whether specifically linguistic or not, on a learner's 'hypothesis space'. Analysis of errors in learning suggests that morphological learning may occur via a probabilistic mechanism, whereas syntactic learning may be based on different, possibly innate, principles. The final postsyntactic stage represents the integration of the newly-emerged syntactic system with the real-world knowledge the child has accumulated.

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 [Eds].