Attainment of sitting and walking predicts development of productive vocabulary between ages 16 and 28 months

Productive vocabulary was measured every four months in 16- to 28-months-olds. Attainment of motor-milestones was also measured. An earlier age of sitting and walking predicted a higher intercept and a larger slope (growth) of productive vocabulary respectively, suggesting that attainment of walking propels linguistic development.

► We longitudinally model growth in productive vocabulary between age 16 and 28 months. ► We examine whether attainment of motor milestones predicts this growth. ► Earlier age of unsupported sitting predicts larger productive vocabulary. ► Earlier age of independent walking predicts faster rate of growth in productive vocabulary. ► Results support the notion of motor milestones propelling linguistic development.