THE FUNCTIONS OF SELF-INJURIOUS-BEHAVIOR - AN EXPERIMENTAL-EPIDEMIOLOGIC ANALYSIS

Data are summarized from 152 single-subject analyses of the reinforcin g functions of self-injurious behavior (SIB). Individuals with develop mental disabilities referred for assessment and/or treatment over an 1 1-year period were exposed to a series of conditions in which the effe cts of antecedent and consequent events on SIB were examined systemati cally by way of multielement, reversal, or combined designs. Data were collected during approximately 4,000 experimental sessions (1,000 hr) , with the length of assessment for individuals ranging from 8 to 66 s essions (M = 26.2) conducted over 2 to 16.5 hr (M = 6.5). Differential or uniformly high responding was observed in 145 (95.4%) of the cases . Social-negative reinforcement (escape from task demands or other sou rces of aversive stimulation) accounted for 58 cases, which was the la rgest proportion of the sample (38.1%). Social-positive reinforcement (either attention or access to food or materials) accounted for 40 (26 .3%) of the cases, automatic (sensory) reinforcement accounted for 39 (25.7%), and multiple controlling variables accounted for 8 (5.3%). Se ven sets of data (4.6%) showed either cyclical or inconsistent pattern s of responding that were uninterpretable. Overall results indicated t hat functional analysis methodologies are extremely effective in ident ifying the environmental determinants of SIB on an individual basis an d, subsequently, in guiding the process of treatment selection. Furthe rmore, an accumulation of assessment data from such analyses across a large number of individuals provides perhaps the most rigorous approac h to an epidemiological study of behavioral function.