Change in these cultural values can be traced to the child welfare movement. In 1961, battered child syndrome was first described, and child abuse emerged as a major social issue. Child abuse includes nonaccidental physical injury or neglect, sexual abuse, and emotional abuse. Abuse may range from severe beatings to failure to provide the necessities of life. While perhaps underestimating the extent of child abuse, available data suggest that the family may be society's most violent institution. While milder forms of abuse are more common, it is estimated that 2,000 to 5,000 children are killed by their parents annually. The current conceptual model of child abuse considers the interplay of social and psychological factors, including the cycle of violence, stress, socioeconomic status, and social isolation. Other factors include large family size, child prematurity, and poor mother-child attachment. In working with abusive families, social workers need strong knowledge of child behavior and development, few managerial tendencies, belief that the parent can change, and a willingness to look at their own feelings about abuse. Training should deal with these areas, as well as with child abuse laws and the operation of the court system. 7 notes.