Onset of pointing and the acquisition of language in infancy

Abstract

Abstract Thirteen girls and 14 boys were tested five times from pre-pointing (8 months) to 14 months on the MacArthur Infant Communicative Development Inventory. The age of pointing onset was established to within 2 weeks. Babies were also tested at monthly intervals on a number of tasks designed to study the relation between language acquisition, fine motor skills, handedness and detour problem solving. Acquisition of fine motor control in the pincer grip precedes pointing. Girls pointed slightly before boys and age of pointing onset (ca ll.3 months) predicts both the number of gestures produced and the number of sounds comprehended at 14.4 months. Unimanual right-handed problem solving sequences predict MacArthur gestures. Both the relative balance of fine motor activity between the hands, and collaborative bimanual activity with right-hand dominance, predict speech comprehension and speech production at 14.4 months. Detour problem solving does not predict any of the language skills measured by the MacArthur test. These results suggest that onset of pointing may be linked both to gesture and to speech through developmental changes in cerebral dominance. It is possible that there are sex differences in this process.