This study investigated the effects of deindividnation, modeling, and private self-consciousness on antisocial and prosocial responses. Groups of four participants (N = 72) were exposed to factorial combinations of situational cues (deindividuatmg Vs. individuating) and modeling (prosocial vs. no model vs. antisocial) and subsequently were given the choice to behave either aggressively or altruistically toward another person. Subjects receiving deindividuating cues produced higher levels of aggression and dispensed greater sums of money compared with individuated participants. Subjects exposed to a prosocial model administered more money than did subjects exposed to the no-model or aggressive model. Although an expected main effect of models on aggression approached significance, a predicted Situational Cues x Model interaction did not. This investigation suggests that subjective deindividuation is a neutral condition. When antisocial environmental cues are present, deindividuated persons are likely to engage in aggressive actions, whereas prosocial cues influence deindividuated group members to behave altruistically. Although deindividuated group members are affected by stimuli such as models, they are not influenced to a greater degree than are individuated people. Finally, these results suggest that when the situational manipulations designed to reduce private self-awareness are salient and powerful, they may affect behavior more than do dispositional levels of private self-consciousness.… the spontaneous and never quite predictable outcry of a crowd is unmistakable, and its effect mormous. It can express emotions of any kind: which emotions often matters less than their strength and variety and the freedom of their sequence. (Canetti, 1963, p. 35). © 1990, Taylor & Francis Group, LLC. All rights reserved.