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Infants who show an early preference for their right hand also show advanced language abilities at 2 months of age. It may be that infants with a dominant hand are better at stacking blocks and picking up other small objects and toys. These activites promote cognitive development, a contributor to language development.

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Are you a righty or a lefty? Peopl—even infants—usually show a preference for the right hand over the left. In most people, handedness is lateralized to the left hemisphere (Annett, 2002). Language is also processed asymmetrically in the brain. For example, infants and adults tend to show activity in their left hemisphere in response to language (Dehaene-Lambertz, 2017), especially in response to their native language compared with nonnative language (Vannasing et al., 2016). Given that hand preference has been observed prenatally (Hepper, 2013), some researchers have begun to examine whether hand preference is an early indicator of hemispheric specialization and thereby language development. What is the relationship between handedness and language development? Does hand preference predict language development in infancy?

Although hand preferences have been observed in the womb, infants show individual differences. Some infants show consistent hand preferences across motor tasks and others show a more unstable pattern, switching hands often (Cochet, 2012; Kotwica, Ferre, & Michel, 2008). Infants who consistently prefer the right hand demonstrate greater left hemispheric specialization than those without a consistent hand preference (E. L. Nelson, Campbell, & Michel, 2015). One longitudinal study followed infants at monthly intervals from 6 to 14 months and again from 18 to 24 months to examine the relationship of handedness and language development (E. L. Nelson, Campbell, & Michel, 2013). Although the infants did not differ on measures of cognition or general motor skills, infants who showed early preferences for their right hand also showed advanced language abilities at 2 months of age. A consistent right-hand preference during infancy suggested greater lateralization and activity in the left hemisphere, in regions long associated with language. It is important to note, however, that an early hand preference predicted advanced language skill, but children without a stable hand preference showed normative language development.

Why is having a consistent hand preference associated with advanced language acquisition? Perhaps infants who show a consistent hand preference are better at manipulating objects than those without a stable preference (Kotwica et al., 2008). Infants’ skill in object manipulation is associated with cognition because it permits infants to examine objects in greater detail (Bruner, 1973). Fine motor skills enable infants to play in sophisticated ways, such as stacking blocks, picking up small objects, and filling cups and other containers—and then dumping out the contents. Infants with a dominant hand show greater skill in manipulating objects and using tools to carry out these tasks (Michel, Campbell, Marcinowski, Nelson, & Babik, 2016)—and each of these activities promotes cognitive development, a contributor to language development.