Emergence and maintenance of stereotypy and self-injury.

A three-level model was used to explain the emergence and maintenance of rhythmic stereotypy and self-injury. Level I represents rhythmic behaviors as internally regulated and common in normally developing infants, but delayed in onset among children with handicapping conditions. Consistent with homeostasis theory, Level II considers stereotypy and self-injury as adaptive responses to under- or overstimulating environments. Level III represents stereotypy and self-injury as learned behaviors emitted to control the behavior of others. The model includes fluid transitions between the levels. Implications for assessment intervention and prevention were discussed and further research suggested.