Date of Award


Degree Type


Degree Name

Doctor of Philosophy (PhD)


Medical Sciences (Growth and Development)


D. Campbell


D. Carr

Committee Member

A. McComas


Language acquisition in relation to sex, manual motor skill and laterality was studied in forty-nine middle class normally developing children. A longitudinal design was employed and testing was done at 18, 24 and 30 months of age. Measures of language function, motor function, lateral asymmetry and general cognitive ability were used. It was predicted that: (a) girls would perform better than boys on the language measures, (b) children who scored high on manual motor tasks would talk better, (c) handedness would not be related to language ability, and that, (d) handedness and motor asymmetries would be observed at 18 months and not change at 24 and 30 months. The girls performed better than the boys on almost all the language measures. There were no sex differences for any of the other tests given. A weak association was found between manual motor skill and language productivity, but handedness and language ability were not related. Hand preference and motor asymmetries were observed at 18 months and maintained at 24 and 30 months. These results further our understanding of language development in young children and may help the assessment and treatment of children with developmental language problems. The measurement of handedness and lateral behaviors in young children permits inferences about hemisphere specialization in the young child. The results of this research support the position that hemispheric specialization does not develop with age but is present from a very early age.

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