Preschool language ability is predicted by toddler hand preference trajectories.

Abstract

Prior work has found links between consistency in toddler handedness for the fine motor skill roledifferentiated bimanual manipulation (RDBM), and language development at 2 and 3 years of age. The current study investigated whether consistency in handedness from 18 to 24 months (N ϭ 90) for RDBM predicts receptive and expressive language abilities assessed using the Preschool Language Scales 5th edition (PLS-5) at 5 years old. Latent class growth analyses identified 3 stable RDBM hand preference trajectories: a left hand preference with moderate right hand use (left-moderate right), a right hand preference with moderate left hand use (right-moderate left), and a right hand preference with only mild left hand use (right-mild left). At 5 years of age, children with a right-mild left handedness trajectory as toddlers scored significantly higher on receptive and expressive language abilities compared to children with a left-moderate right hand preference. Children with a right-mild left hand preference for RDBM also scored significantly higher on receptive language abilities compared to children with a rightmoderate left RDBM hand preference. Children with left-moderate right and children with a rightmoderate left hand preference for RDBM as toddlers did not differ in receptive or expressive language abilities at 5 years. Results indicate that individual differences in hand preference consistency for fine motor skill in toddlerhood have cascading effects on language outcomes into the preschool years.

Insights Into Human and Nonhuman Primate Handedness From Measuring Both Hands

“…Thus, some children exhibit consistent hand-use preferences from infancy, whereas others are variable. Consistency in the trajectory of hand-use preference matters because handedness trajectories for later-emerging RDBM skill predict language outcomes when children are 2, 3, and 5 years old (Gonzalez et al, 2020). Moreover, this link to language outcomes extends the cascade theory further in developmental time, past the emergence of a hand-use preference in RDBM tasks.…”

Handedness Development: A Model for Investigating the Development of Hemispheric Specialization and Interhemispheric Coordination

“…In addition, toddlers who had the strongest and most consistent righthand-use preference from 18 to 24 months had higher expressive and receptive language scores at three years of age (measured with Preschool Language Scales, 5th edition) than toddlers with a left-hand-use preference or with a weak right-hand-use preference [284]. By five years of age, children, who as toddlers, had a strong right-hand-use preference, scored significantly higher on both expressive and receptive language skills (PLS-5) compared to those with a left-hand-use preference or a weak right-hand-use preference [285]. Thus, individual differences in fine motor skills (RDBM) during toddlerhood can have cascading effects on language ability during the preschool years.…”

Which hand knows the “right” word? What hand selection reveals about vocabulary in pre‐and school‐aged children

“…While the scope of this specific study focuses on children who are already speaking, an additional benefit of developing a motor intervention is that it could be applied to children who are nonverbal. The previously cited studies linking increased right-hand use and later proficient language development (Gonzalez et al, 2020;Nelson et al, 2017) suggests this could provide a very effective training tool.…”

“…Children who demonstrated inconsistent selection of a hand for writing were more likely to have poor vocabulary skills (Crow et al., 1998). A recent longitudinal study found that consistently higher right‐hand use for object manipulation during a role‐differentiated bimanual task in infancy predicted better language skills (expressive and receptive) at 5 years of age (Gonzalez et al., 2020). These two studies suggest that the relationship between lateralized motor actions and vocabulary persists throughout childhood, but clearly more research is needed to firmly establish this link.…”