Handedness for grasping objects and pointing and the development of language in 14-month-old infants

Abstract

The goal of this study was to evaluate the relationship between object-related handedness and handedness for communicative gestures. We observed 22 infants aged 14 months on a baby laterality test consisting of grasping objects in different conditions, on a pointing task with targets placed out of reach at different spatial positions from left to right, and on word understanding and word production. Results show that 77% of infants pointed to the left, middle, and right targets. The majority of infants were right-handed for pointing—except for the far left target—and, to a lesser extent, for grasping objects, but there was no significant relation between the two measures of handedness. The frequency of pointing tended to be related to the number of words understood, and infants right-handed for pointing understood and produced significantly more words than non-right-handed pointers. These results are interpreted as confirming the link between pointing and language development, and as showing that communicative gesture lateralisation is not a mere consequence of object-related handedness, at least during development. Whether lateralised communicative gesture reinforces a pre-existing tendency to use the right hand to interact with objects remains an open question.

Keywords:

• Handedness
• Grasping
• Pointing
• Language
• Development

Acknowledgements

This study was supported by the ANR program, contract no. 08-3_311472. The authors wish to thank S. Kern for her French adaptation of the MacArthur language test, and J. Vauclair and H. Cochet for their helpful comments on the paper.