Longitudinal development of language and fine motor skills is correlated, but not coupled, in a childhood atypical cohort.

The atypical group was smaller than the typical group (74 versus 165), which limited the multigroup comparisons. The best multigroup models still had relatively poor fit overall, and differences among complex models were marginal. Language and motor abilities were assessed with one rater-reported measure, the MSEL, which may not capture all variability in language acquisition. The study used secondary data and could not use auxiliary variables for missing data. This limits generalizability. No intervention was tested, so the paper cannot show whether therapy changes these trajectories.

The authors disclosed financial support from ERC, NWO, the Sir Henry Wellcome Trust, MRC, the Van der Gaag Grant, the Amsterdam University Fund, and ZonMW. The BASIS project was supported by the UK Medical Research Council, the BASIS funding consortium led by Autistica, and EU-AIMS. No other conflicts of interest are reported.

Do not conclude that early fine motor problems cause later language delays or that language problems drive motor delays. The study found growth rates were strongly correlated, but no evidence that starting level in one domain predicted change in the other.