One researcher characterizes children's play between 10 and 12 years of age in terms of the gang spirit. Generally, the gang spirit fades after 16 years of age; teenage vandals may be "trapped" in an earlier stage of development. Other psychologists believe that a certain degree of aggression and violence should be encouraged in children and young people through games and sports. When young children show aggressiveness or hostility, they are usually assertive and should be encouraged to direct their abilities into constructive channels. Additional research indicates that aggression can be caused by parental domination. In examining whether the tendency toward vandalism and violence stems from home, school, or other sources, the author contends that parents and guardians should be held responsible in part because their examples and attitudes toward life are usually emulated by children. Parents and teachers alike are in a position to influence young people, as well as religious leaders. The author notes that attitudes of young people have changed due to economic and social influences and that young people know their rights.