The longitudinal relation between motor and language skills at two and four-to 4.5 years of age in a large Singaporean cohort

Early language is intricately related to the development of other skills. Motor skills, in particular, have been associated with language development, but the precise relations between these domains is a matter of ongoing research. Here we examined the longitudinal relations between fine- and gross-motor skills and language abilities in a large population cohort (N = 885, 49% female) from Singapore. Using a cross-lagged panel model with data from 9 to 48 months of age, we investigated both within-time associations and directional effects between motor and language domains. We found significant concurrent associations between motor and language skills. Fine-motor skills at 9 months predicted language development at 18 months, even after controlling for demographic factors. None of the other cross-domains paths was significant. In order to explain this discrepancy with past research, we therefore also explored without controlling for these factors. This latter analysis revealed more predictive paths from gross and fin- motor to language development, from the age of 9 months up to two years, suggesting that previous findings might be explained by confounding factors. Our findings highlight the importance of controlling for confounding factors when examining the relation between motor and language development.