Verbal/vocal interactions of three Japanese mother–child dyads were
examined when the children were 1;0, 1;2 to 1;3, 1;6 to 1;7, and 1;8
to 1;9 to determine whether mothers provide information which may
facilitate the elaboration of child lexical forms during the transition from
the prelinguistic to the linguistic period. Mothers were likely to
reproduce only the child's word-like utterances, both well- and ill-formed. This provided an opportunity for the child's ill-formed word-like utterance to be contrasted with an immediate maternal response.
This finding, along with results showing within-child variability of
lexical forms, suggested that maternal contrastive replies 1) signal errors
to the child (cf. Saxton, 1997), and 2) may promote the child's selection
and stabilization of production alternatives which are more accurate.
Maternal reproductive responding presumably originated in their tendency to seek content-oriented communication, as was reflected in
mother's growing inclination to continue verbal interactions following
the child's non-word-like vocalizations.