Characteristics of early rhythmic behaviors in children at risk for developmental disorders.
OBJECTIVE: Abnormal stereotyped behaviors are a significant problem for many individuals with mental retardation or mental illness. To increase understanding of the development of abnormal stereotyped behaviors, the authors investigated the early rhythmic behaviors of children at increased risk for developmental delays. METHOD: Rhythmic behaviors in 13-month-old children born prematurely and in children born at term were coded from laboratory videotapes of structured interaction segments. RESULTS: While few differences in early rhythmic behaviors were found between children born prematurely and control children, some relationships with cognitive outcomes at 2 years were identified after controlling for family socioeconomic status. However, the direction of the association was dependent on the specific coded situation. No differences in the durations of rhythmic behavior bouts were found between the groups. CONCLUSIONS: The findings indicate that even topographically similar behaviors have different functional significance in different settings. In at least some settings, rhythmic behaviors in infancy and early childhood seem to facilitate development. The fact that specific forms of rhythmic behaviors did not differ on the basis of prematurity status suggests that abnormal stereotyped behaviors have an onset later than 13 months.