Developmental dynamics of SES-related differences in children's production of obligatory and variable phonological alternations

Numerous studies conducted in both the psycholinguistic and sociolinguistic fields have established that the parents' socioeconomic status (SES) influences several aspects of children's language production. Moreover, a number of psycholinguistic studies strongly suggest that these differences are due in part to differences in the nature and the quantity of input that children are exposed to. Despite these advances, in our knowledge, the developmental dynamic of the differences still has to be described and explained. The aim of the current study is to examine this dynamic in the production of liaison, a phonological alternation in French which is, in some cases, obligatory and used in a uniform manner by adults and, in others, a sociolinguistic variable whose frequency of use depends on the speaker's SES. One hundred and eighty-five children aged from 2;3 to 6;0 belonging to two distinct SES groups (higher and lower SES) and subdivided into four age-groups participated in a picture naming task eliciting the production of obligatory and variable liaisons. First, an analysis of the three types of child production (correct liaison, omission, replacement) confirms that the linguistic forms which are present in the input increase with age in children's productions, whereas those which are absent tend to disappear. Second, the evolution of the SES-related differences depends on the uniformity or heterogeneity of usage in the social groups: convergence for obligatory liaison and divergence for variable liaison. The discussion of these findings combines both psycholinguistic and sociolinguistic perspectives since both have stressed the importance of exposure to linguistic forms in the input.