Degrees of Self-Abuse: Psychologists have identified three subcategories of self-mutilation: moderate, stereotypic and major. The category most people are familiar with, moderate self-mutilation, is the most widespread throughout the population. Moderate self-mutilation consists of cutting, burning, carving and stabbing one's body with sharp objects. Stereotypic self-mutilation takes the form of head banging or arm biting. Major self-mutilation is particularly extreme and uncommon. This form of self-injury often involves limb amputation or castration.