Longitudinal assessment of stereotypic, proto-injurious, and self-injurious behavior exhibited by young children with developmental delays.

Twelve children (CA, 12 to 32 months) with developmental delay were observed in their homes during monthly analogue functional analysis probes to document patterns of emerging self-injurious behavior. Two patterns of emerging self-injury were observed for 5 participants: (a) The topography and functional analysis pattern remained the same, but the behavior eventually caused tissue damage; or (b) a new topography emerged that was similar to an established stereotypic motor behavior. Functional analysis results were inconclusive for the majority of target behaviors across participants due to undifferentiated responding across conditions. One participant exhibited two topographies that appeared to become sensitive to positive reinforcement over time. Results are discussed in terms of implications for future research on early intervention and prevention of self-injury.