Robert Merton's deviance theory posits that anomie arises from a socially structured situation in which a lower socioeconomic class, frustrated in legitimately attaining financial goals, turns to illegitimate or innovative means. With reference to his typology of individual adaptations, it could be hypothesized that most inmates are retreatist, attempting to avoid trouble in prison. A few, however, try to adapt by attempting to thwart prison restrictions through the use of illegitimate opportunity structures, and, if frustrated, are placed in a situation of anomie. The result is instigation of a riot to obtain goals through illegitimate means. However, this theory does not explain why, in many incidents, rioters have no specific demands, inmates who act as spokesmen for rioting prisoners are often not the instigators, and riots usually do not begin as organized and planned movements but start spontaneously and unpredictably, with the power structure and direction emerging as the riot is in process. A list of demands appears to often legitimize the behavior rather than cause it, and many riots are violent and slow to defuse even if the administration accedes to inmates' demands. Durkheim's theory of anomie is a better explanation of riot behavior. Applied to prison riots, it can be used to theorize that any change in administration and organization of the prison (positive or negative) can disrupt the equilibrium and lead to changes in inmates' aspirations and expectations that are not likely to be fulfilled. From this perspective, a prison riot appears to be an emotional reaction resulting from moral indignation. This not only explains the violent nature of many riots, but the fact that the institution of reforms is not preventive. It also helps explain why riots often are unplanned and happen in spurts since changes are often exacted in response to recent riots. Forty-three references are included.