A gang is a group of people who through the organization, formation, and establishment of an assemblage share a common identity. In early usage, the word gang referred to a group of workmen. In England the word is still often used in this sense, but it later underwent pejoration. The word gang often carries a negative connotation; however, within a gang which defines itself in opposition to mainstream norms, members may adopt the phrase as a statement of identity or defiance.

Gang activities are not restricted to typical organized crime groups, but may be associated with a general class of behavior in which collective action and support of communal interests and goals serves to achieve social cohesion or solidarity "especially in gangs, cults, unions, political parties or movements, and religious sects."An article in the Journal of Contemporary Criminal Justice defines a street gang or troublesome youth group as "any durable, street-oriented youth group whose own identity includes involvement in illegal activity". This definition was developed over 5 years and agreed on by more than 100 gang research scholars in the United States and Europe. It is a minimalist definition specifically designed to enhance comparative street gang research. Because of the frequently ethnic minority dimension to gangs, some studies of the sociology of gangs contend that gang culture arises and depends, at least in part, upon aspects of social marginality and deviance. Or it may be an attempt to receive attention lacking from potentially abusive family figures.

Historical criminal gangs

A wide variety of historical gangs, such as the Chinese Triads, Japanese Yakuza, American Old West outlaw gangs and Italian Mafia crime families has existed for centuries. These early gangs were known for many criminal activities, but in most countries could not profit from drug trafficking prior to twentieth century drug prohibition laws such as the 1912 International Opium Convention and the 1919 Volstead Act. Gang involvement in drug trafficking increased during the 1970s and 1980s, but some gangs continue to have minimal involvement in the trade.

Modern usage

In modern usage, gang often refers to loosely organized groups that control a territory through readiness to use coordinated violence, especially against other gangs. Violence also serves to maintain organization within the gang and to control gang members (Decker and Van Winkle, 1996; Horowitz, 1983; Sanchez-Jankowski, 1991; Yablonsky, 1962) Gangs are as diverse and dissimilar as the ideologies and belief systems which influence and motivate them. Extremist and hate groups in some states have acquired the label, as the extremist groups operate very similarly to corporate gangs. While hierarchy, colors, and turf are not emphasized as much within these extremist groups, symbols, signs, codes, special languages, and group collaboration and participation in patterns of criminal activity are as much a part of the gang type behavior as they are to more traditional 'street gangs'. 'Territories' have expanded to include the Internet for some gangs. Crips, Bloods, Latin Kings, Sureños, Norteños, 18th Street gang, MS-13, and other "web bangers" are among some gangs posting on personal and social networking Web sites taunting other gangs, boasting of illegal exploits, and, according to George W. Knox, director of the National Gang Crime Research Center, influencing and recruiting new members. Tod Burke, a criminal justice professor at Radford University in Virginia states: “Gangs already have their own alphabet, their own language, their own hand signals, so why not use the Internet?” Gang members, using home computers communicate with each other using their own coded language to brag about criminal exploits and to organize crimes on the street, including fights with rival gangs. White Aryan Resistance (WAR), the World Church of the Creator (WCOTC), and the Ku Klux Klan (KKK) are three American-based white-supremacist or neo-fascist groupuscules or gangs who have been quick to exploit the advantages the Internet and the World Wide Web offer for organizing, recruiting, and developing their small, splinter groups of extremists. While the Internet provides these gangs with the opportunity to communicate with a wider audience, the threat of increased influence on disenfranchised and underprivileged youths may be exaggerated. Gang members have also been joining and organizing within the U.S. military and learning military skills in Iraq, a phenomenon an FBI report calls "a threat to law enforcement and national security." In environments with few social supports, gangs provide young members a sense of belonging, and protection from other gangs; often, where prospects for gainful employment are poor, they also provide an illegal means of earning a living.