This study explores the use of an operant methodology to examine the functional relationships between self-injury and environmental factors in nine developmentally disabled individuals. The research involved repeated exposure to various conditions differing in play materials, experimenter demands, and social attention. Results showed significant variability in self-injury levels across and within subjects, with six subjects consistently displaying higher self-injury under specific conditions, suggesting environmental influences on the behavior. The study discusses implications for treatment, emphasizing the need to identify maintaining factors. Self-injury is a chronic, often severe behavior with unclear causes and significant risks. Previous research has focused on eliminating self-injury through operant conditioning methods, though mixed results have been reported. Effective treatments include punishment, but concerns about safety have led to recommendations limiting its use. The study highlights the importance of identifying the conditions under which treatments are effective. The study used a multielement design to assess how different environmental conditions affect self-injury. Conditions included social disapproval, academic demand, unstructured play, and alone. Results showed varied patterns, with some subjects showing increased self-injury in specific conditions. The study suggests that self-injury may be maintained by multiple reinforcement sources, including social attention and sensory stimulation. The study found that self-injury levels varied significantly between and within subjects, with some showing consistent patterns under specific conditions. The results indicate that self-injury may be influenced by environmental factors, and that identifying these factors is crucial for effective treatment. The study also highlights the need for further research to understand the exact contingencies maintaining self-injury and to develop more effective interventions. The methodology used in the study provides a framework for examining environmental influences on self-injury, which could improve treatment approaches.This study explores the use of an operant methodology to examine the functional relationships between self-injury and environmental factors in nine developmentally disabled individuals. The research involved repeated exposure to various conditions differing in play materials, experimenter demands, and social attention. Results showed significant variability in self-injury levels across and within subjects, with six subjects consistently displaying higher self-injury under specific conditions, suggesting environmental influences on the behavior. The study discusses implications for treatment, emphasizing the need to identify maintaining factors. Self-injury is a chronic, often severe behavior with unclear causes and significant risks. Previous research has focused on eliminating self-injury through operant conditioning methods, though mixed results have been reported. Effective treatments include punishment, but concerns about safety have led to recommendations limiting its use. The study highlights the importance of identifying the conditions under which treatments are effective. The study used a multielement design to assess how different environmental conditions affect self-injury. Conditions included social disapproval, academic demand, unstructured play, and alone. Results showed varied patterns, with some subjects showing increased self-injury in specific conditions. The study suggests that self-injury may be maintained by multiple reinforcement sources, including social attention and sensory stimulation. The study found that self-injury levels varied significantly between and within subjects, with some showing consistent patterns under specific conditions. The results indicate that self-injury may be influenced by environmental factors, and that identifying these factors is crucial for effective treatment. The study also highlights the need for further research to understand the exact contingencies maintaining self-injury and to develop more effective interventions. The methodology used in the study provides a framework for examining environmental influences on self-injury, which could improve treatment approaches.