a b s t r a c tThis study investigated the development of hand preference for bimanual manipulative activities and pointing gestures in toddlers observed longitudinally over a 5-month period, in relation to language acquisition. The lexical spurt was found to be accompanied by an increase in the right-sided bias for pointing but not for manipulation. Moreover, results revealed a significant correlation between hand preference for imperative pointing gestures and manipulative activities in children who did not experience the lexical spurt during the observational period. By contrast, measures of handedness for declarative pointing were never correlated with those of handedness for manipulation. This study illustrates the complex relationship between handedness and language development and emphasizes the need to take the different functions of pointing gestures into account.Ó 2011 Elsevier Inc. All rights reserved.
IntroductionA small body of research has described the development of hand preference in relation to language development, although this topic represents a significant source of information for assessing developmental changes of these two main functional asymmetries. Because the use of one hand for a specific activity mostly reflects the predominant involvement of the contralateral hemisphere, this measure provides an innovative means for investigating its relations with the cerebral control of speech during development. Moreover, different measurements of handedness may allow us to determine whether manipulative activities and communicative gestures are linked to speech at varying degrees. In the
Contents lists available at ScienceDirectJournal of Experimental Child Psychology jo urnal homepage: www.elsevier.co m/locate/jecp current study, language level and hand preference for both bimanual manipulation and pointing gestures were measured longitudinally in toddlers between 13 and 21 months of age in an attempt to unravel the complex relationships between language acquisition and the development of handedness. We focused on a key period of language development, namely the lexical spurt, whose onset was expected to be more closely linked to hand preference for pointing than to handedness for noncommunicative actions in the course of development. Moreover, speech-gesture relationships were expected to vary depending on the function served by pointing gestures.