Background: Behavioural interventions conceptualise self-injurious behaviour (SIB) as developing from early repetitive behaviours through acquisition of homeostatic functions in regulating stimulation and subsequent shaping into SIB through socially mediated or automatic operant reinforcement. Despite high success rates, such interventions rarely completely eliminate SIB, and overall effectiveness has not increased since the 1960s. Methods: Research (excluding studies of single genetic syndromes) on the early development, functional properties and phenomenology of SIB in persons with intellectual disabilities (IDs) published from 1999 to 2010 inclusive is reviewed. Results: Despite evidence to support the operant shaping hypothesis, in some cases tissue-damaging SIB, especially head-banging, emerges at a similar or younger age than stereotyped behaviours or "proto-SIB", often associated with tantrums following frustrative non-reward and/or abrupt situational transitions. Many young children show undifferentiated patterns of responding in functional analyses of SIB, and SIB is associated with aggression and impulsivity as well as with repetitive behaviour. Conclusions: One dynamic in the development of SIB may be Pavlovian conditioning of aggression, originally elicited by aversive events or frustrative non-reward, to stimuli associated with such situations. Integration into operant technology of interventions based on Pavlovian principles such as graduated exposure (with or without counterconditioning) to aversive stimuli may enhance the effectiveness of behavioural interventions.