Aggression can a problem for children with both normal development and those with psychosocial disturbances. Aggression constitutes intended harm to another individual, even if the attempt to harm fails (such as a bullet fired from a gun that misses its human target). There is no single theory about the causes of aggressive behavior in humans. Some believe aggression is innate or instinctive. Social theorists suggest the breakdown in commonly shared values, changes in traditional family patterns of child-rearing, and social isolation lead to increasing aggression in children, adolescents, and adults. Aggression in children correlates with family unemployment, strife, criminality, and psychiatric disorders.