One study indicates that antisocial personality usually develops in early childhood, particularly among boys. In another study, among children referred to a school guidance clinic for antisocial behavior, 25 percent turned out to be antisocial adults. Studies also show that antisocial disorders in children are frequently passed from one generation to the next and that childhood symptoms predicting adult delinquency include theft, incorrigibility, running away from home, truancy, associating with other delinquent children, staying out past the hour allowed, discipline problems in school, and academic difficulties. Among antisocial children, boys outnumber girls by a four to one margin. Black children have higher school dropout and juvenile delinquency rates than white children, but some racial discrimination can be explained in terms of quality of education, prejudice, and stereotypes. Broken homes and social class do not definitively predict antisocial behavior, although the extent of parental discipline plays a role in violent and other antisocial behavior in children and later as adults. Study findings on the role of family separation in antisocial behavior are mixed. With respect to biological influences, several investigators suggest that young people prone to violent behavior may differ from other youth in hormone and neurotransmitter activity. 8 references