Young children's acquisition of the movement aspect in American Sign Language: parental report findings

The acquisition of the movement aspect of American Sign Language signs was examined longitudinally in 9 young children of deaf parents. During monthly home visits, the parents demonstrated on videotape how their children formed the different signs in their lexicons. The parents also demonstrated how they formed or modeled these same signs. Overall, the children correctly produced 61.4% of the movements that were present in the adult sign models. Although the production accuracy of the movement aspect of signs did not improve over the course of the study, the number and complexity of movements produced by the children did increase as they got older and their vocabularies grew in size. Of the different sign movements, contacting action was by far the most frequently produced. The children were also relatively successful in their production of closing action and downward movement. The order of acquisition for the remaining ASL movements, however, was quite variable, with the exception that bidirectional movements tended to be produced more accurately than unidirectional movements. The relationship between children's early rhythmical motor behaviors and the development of sign movements is discussed.