Of 14 studies conducted between 1947 and 1979, all but one found that mentally retarded persons were either unsatisfactory parents or overrepresented among abusing and neglecting samples. Child protection studies have generally found an association between parental intelligence and parenting ability and show that battering is more common among borderline or mentally subnormal parents. The mental retardation literature similarly has shown a link between parental mental retardation and child maltreatment. Children of mentally retarded parents appear to be more likely to come to the attention of child protection agencies and to require State intervention than are control parents. Further, mentally retarded mothers have been found to have more controlling, protective, and punitive childrearing attitudes than control mothers. Clinical observations also support an association between parental mental subnormality and increased risk of child abuse and neglect. While these studies support the association, they suffer from small sample size, lack of control groups, and inadequate measurement of such critical variables as IQ, parental competence, and child maltreatment. More research is needed into how much parents care for their children and approaches to intervention. 1 table, 6 notes, and 71 references. (Author abstract modified)