gang, group of people organized for a common purpose, often criminal. Gangs of criminals were long known on the American frontier and also flourished in urban settings. Notorious were the outlaws led by Jesse James and his brother, the Sydney Ducks of San Francisco (active in the 1850s), and the Hudson Dusters of turn-of-the-century New York City. Modern criminal gangs are largely urban and highly organized (see organized crime). Adolescent gangs before World War II were generally poverty-area recreational groups that turned to crime under the influence of adult gangs. Often the groups were rehabilitated through recreational leadership and guidance in community centers. In the late 1940s fighting gangs arose in the poverty areas of most large cities. Uniting to seek security and status in a discouraging environment, the young members divide their neighborhoods into rival territories and amass homemade and stolen weapons. Boundary violations or other insults invite intergang fights in streets or parks. Most fighting gangs are organized intricately, with caste systems and with officers who arrange battles and prepare strategy; the gang may range in size from several members to over 100. Factors related to the development of delinquent gangs include blighted communities, dropping out of school, unemployment, family disorganization, neighborhood traditions of gang delinquency, psychopathology, and ethnic status. Gangs provide acceptance and protection to inner-city youth; in Los Angeles gangs doubled from 400 in 1985 to 800 (with 90,000 members) in 1990. See also juvenile delinquency.

chain gang: see convict labor.

Gang of Four, term of opprobrium given by the Chinese Communist authorities to four persons held responsible for the excesses of the Cultural Revolution (1966-69). They were also accused of trying to seize power after the deaths (1976) of Mao Zedong and Zhou Enlai. The most notable of the Gang of Four was Jiang Qing, Mao's widow. The others were Wang Hongwen, Yao Wenyuan, and Zhang Chunqiao. They were imprisoned in 1976, tried in 1980, and sentenced in 1981. Their sentences ranged from death (later commuted to life in prison) to 20 years in prison.

Most powerful members of a radical political elite convicted for implementing the harsh policies of Mao Zedong during the Cultural Revolution. The four were Wang Hongwen, Zhang Chunqiao, Yao Wenyuan, and Mao's third wife, Jiang Qing. Manipulating the youthful Red Guards, the Gang of Four controlled four areas: intellectual education, basic theories in science and technology, teacher-student relations and school discipline, and party policies regarding intellectuals. The turmoil of the Cultural Revolution subsided after 1969, but the Gang of Four maintained their power until Mao's death in 1976, when they were imprisoned; they stood trial in 1980–81.

Learn more about Gang of Four with a free trial on Britannica.com.