Research on child language acquisition confirms the importance of early language development for later language and literacy skills (Dickinson, Golinkoff & Hirsh-Pasek, 2010; Lee, 2011), and documents great individual variability in children’s acquisition rates (Fenson et al., 1994). Recent research has also widened the focus to include the impact of early gestures (e.g. Rowe & Goldin-Meadow, 2009). This study aims to investigate early communicative development in a sample of Swedish children based on parental report, using Swedish versions of the MacArthur-Bates CDI (Berglund & Eriksson, 2000; Eriksson & Berglund, 1999). In particular, variables such as early communicative gestures, receptive and productive vocabulary, and the syntactic/grammatical measure M3L (the Mean Length of Utterance score of the three longest utterances parents have heard their child say) are explored. The specific target group here is a subsample (from a total sample of 348) consisting of 128 children with complete records collected at six-month intervals (12, 18, 24 and 30 months of age). In the analysis, gender and children’s ability to use the pointing gesture at 12 months are used as grouping variables.
The analysis entails first looking at general trends in the data, and thereafter examining individual trajectories, especially extreme ones. Growth curve modelling is employed to describe trajectories of productive vocabulary development, first with gender as the grouping variable, and secondly, with the pointing gesture at 12 months of age. Since preliminary results show different variation in the response between boys and girls, different covariance structures are used for modelling. Moreover, banded covariance structure is utilized to take into account strong correlations between neighboring time points (12-18, 18-24, and 24-30 months). Testing fixed effects reveals highly significantly different slopes for girls and boys. The banded covariance structure is also used in the analysis of productive vocabulary with pointing as the grouping variable. Taking into account heterogeneity in the two groups, results also indicate highly significant differences in vocabulary growth for pointers vs. non-pointers. However, separate analysis of the two groups is needed before further conclusions can be made. It must also be stressed that the data comes from parental report, and observational knowledge of both parental and child gestures is lacking. However, the results of this study definitely contribute to the international body of knowledge with data from the Swedish context. Furthermore, results regarding early communication are of interest for parents, child- and healthcare personnel, as well as educational practitioners.