Bystander anonymity and reactions to emergencies

Two experiments with 179 undergraduates investigated the impact of anonymity on bystander reactions to emergencies and on the timing of bystander decision making. The experiments differed in the nature of the emergency (violent assault vs seizure) and in the speed with which the emergency developed from relative ambiguity to unequivocal clarity concerning the victim's need for help. In both experiments, an additional bystander's awareness of the emergency and the S's anonymity were crossed in a 2 × 2 factorial design. Anonymity vis-à-vis the victim had no effects on helping. Anonymity vis-à-vis the other bystander did affect helping, apparently by reducing evaluation apprehension. Whether evaluation apprehension enhances or inhibits helping depends on the expectations attributed to other bystanders. The timing of effects suggests that when emergencies are ambiguous, anonymity (through reduced involvement) delays making the decision regarding whether help is appropriate. Once emergencies are clear, anonymity (through evaluation apprehension) influences the decision regarding one's own obligation to intervene. (15 ref) (PsycINFO Database Record (c) 2006 APA, all rights reserved).