For each of these categories, analysis focuses on defining the problem, estimates of incidence and prevalence, problems of discovery and processing of cases within the criminal justice system, and intervention and prevention. Characteristics of abusers and their victims for each type of violence are profiled with respect to age, sex, socioeconomic status, family dynamics, and personality factors. Violence against elders usually involves very old, dependent, and mentally or physically impaired females. It occurs more frequently in middle and lower classes and is more likely to involve psychological maltreatment, financial exploitation, and physical neglect than actual battery. It is difficult to investigate and prosecute. Supportive services for the elderly and their caretakers can prevent elder abuse. While maltreated adolescents constitute half of child abuse cases, the causes and consequences may be different. Such adolescents are unlikely to tell anyone of the problem and are frequently disbelieved or blamed. They often cope by running away and are likely to enter the criminal justice system as status offenders. Violence against parents by offspring may be a response to prior victimization or may occur for no motive. Sibling violence, including sexual exploitation, occurs more frequently than any other form of family violence but is least likely to be reported to authorities. 19 footnotes and approximately 160 references. (Author abstract modified)