The role of gestures and babble in the vocabulary growth of children aged 8-18 months.
Amy Bidgood, Thea Cameron-Faulkner, Samantha Durrant, Michelle Peter and Caroline Rowland presented this paper at the 1st Lancaster Conference on Infant and Child Development in Lancaster, UK.
The idea that language acquisition develops from children’s early non-communicative abilities is central to many constructivist approaches (see Clark, 1993; Tomasello, 2003). Studies have investigated the increasing complexity of infants’ gesture use (e.g. Cameron-Faulkner et al., 2015) or the relationship between gesture and vocabulary growth (e.g. Bates & Dick, 2002; Iverson & Goldin-Meadow, 2005). Others have investigated the effect of babble on language production (McGillion et al, in press). However, none have investigated all predictors together in the same children, so we cannot draw robust conclusions about the relative importance of each, or relationships between predictors. The current study investigated if infants’ showing and giving gestures predicted declarative pointing, if pointing predicted later receptive vocabulary, and if early vocal production predicted later expressive vocabulary. Eighty infants participating in the longitudinal Language 0-5 Project took part in structured 25-minute play sessions at11 and 12 months, designed to elicit a range of gestures. Vocabulary was measured using the UK-CDI at both sessions and at 15 months. Vocal production measures were taken from LENA recordings and parental report of infants’ babble. Preliminary regression analyses (N=10) suggest infants’ showing and giving gestures at 11 months predicted their declarative pointing at 12 months (R2=0.30, F(1,9)=3.37 p=0.10) and that declarative pointing at 11 months predicted receptive vocabulary at both 12 (R2=0.66, F(1,9)=15.70, p=0.004) and 15 months (R2=0.51, F(1,9)=8.45, p=0.020). We found no relationship between infants’ early vocal production, measured either by parental report or by LENA child vocalisation counts, and expressive vocabulary. In summary, our results show a line of predictive relationships: from hold-out and give gestures, through declarative points, to vocabulary growth. We discuss the relationship between early communicative competence and the developing complexity of early gestures, and potential reasons why some gestures, in particular, may be predictive of later language growth.