Associations between early language, motor abilities, and later autism traits in infants with typical and elevated likelihood of autism.

The effect size for the fine motor and expressive language association was modest (R2 = 0.117). The study relied on parental reports for the Vineland and SRS measures, which can introduce shared method variance, although the authors note that correlations with observational Mullen scores suggest this did not account for all effects. The sample size was not large enough to support more complex models, and some models failed to converge when autism cases were excluded, limiting the ability to determine if findings are specific to those who later receive a diagnosis. The study did not assess clinical outcomes or interventions, only associations between developmental domains and trait scores.

Funding was provided by the UK Medical Research Council, the BASIS funding consortium led by Autistica, and Autism Speaks. Prof Charman has served as a paid consultant to F. Hoffmann-La Roche Ltd. and Servier, and received royalties from publishers. Prof Johnson received royalties from publishers. The funders had no role in the study design, data collection, analysis, or manuscript preparation.

Do not interpret these associations as evidence that treating fine motor delays will prevent autism or that motor delays cause language delays. The study describes developmental links in a high-risk group, not the efficacy of an intervention, and the contribution of individual components cannot be separated from the broader developmental trajectory.