Determinants of amounts of stereotyped behavior in normal human infants

Abstract

Rhythmical stereotyped movements are common behaviors in normal infants, but their function has remained obscure. In this study, twenty normal infants were observed in their homes every two weeks during their first year to compare the number of bouts of rhythmical sterotyped behavior with the ongoing behavioral characteristics of the infant and the related activities of his or her caregiver. The single variable accounting for the most variance in the amount of stereotypy was the frequency of vestibular stimulation of the infant from being rocked, jiggled, bounced, and carried by the caregiver. Stereotypy was inversely related to amount of vestibular stimulation. Stereotypy was also inversely related to frequency of behaviors which involved close contact with the caregiver, but was directly related to being placed in locations which comparatively restrict movement such as infant seats. Infants who performed many bouts of rhythmical stereotypy were less likely to be sleepy or fussy during the observation. These results suggest that a defficiency of vestibular stimulation may be one determinant of persistent stereotypy in infants. © 1980.