Parents who physically abuse their spouses are more likely than others to physically abuse their children. However, it is impossible to know whether marital strife is a cause of child abuse, or if both the marital strife and the abuse are caused by tendencies in the abuser. Sometimes, parents set expectations for their child that are clearly beyond the child's capability. When parents' expectations are far beyond what is appropriate to the child (e.g., preschool children who are expected to be totally responsible for self-care or provision of nurturance to parents) the resulting frustration caused by the child's non-compliance is believed to function as a contributory if not necessary cause of child abuse.