Publisher Summary This chapter provides an overview of some historical as well as contemporary, neo-psychodynamic theories of self-injurious behavior, though none of them were developed explicitly with the intellectually disabled population in mind. The chapter also presents several models to explain the self injurious behavior, such as psychodynamic models and gene-brain-behavior model, and the risk factors associated with the self injurious behavior, including genetic risk factors, neurological risk factors, mental health risk factors, genetic risk factors, and perinatal risk factors and stress. Insecure attachment can lead to negative self-expectations and pessimistic expectations of others, and of the relationships one can have with others and may set the stage for a later development of self-injurious behavior. Students with self-injurious behavior reported significantly more anxiety, intropunitive hostility, and extra-punitive hostility than the control group, while people who engage in self-injurious behaviors have an unstable self and a disturbed regulation of self-esteem. Neuroscience, genetics, and psychopharmacology are concerned with the biological components of the behavior; however, when all of the known facts about a given aspect of self-injurious behavior are in accordance across the molecular and molar levels, confidence in its validity is increased.