Ten years of research on group size and helping.

In the decade following Latane and Darley's publication of the discovery that the presence of other people inhibits an individual from intervening in an emergency, numerous researchers have attempted to replicate this finding, extend its range of applicability, and determine what boundary conditions limit it. In the present article, we review both published and unpublished research, with special attention to the nature of the precipitating incident, the ambiguity of the helping situation, laboratory versus field settings, characteristics of the subjects, of the victim, and of other bystanders, and the amount and kinds of communication among bystanders. We conclude that, despite the great diversity of styles, settings, and techniques among the studies, the social inhibition of helping is a remarkably consistent phenomenon; but we identify some conditions under which the effect can be weakened or eliminated. Finally, we explore the implications of these findings for assessing and increasing a victim's likelihood of receiving help. Some 10 years have passed since Latane and Darley (1970) published their monograph reporting the results of a program of research on bystander intervention in emergencies. This research provided strong support for the general proposition that "the presence of other people serves to inhibit the impulse to help " (p. 38), Their work elicited a good deal of interest, and it has stimulated a large amount of subsequent research in this area. We see at least four reasons for the interest generated by this research. First, its high degree of mundane realism (Aronson & Carlsmith, 1968) spoke to an issue of widespread public concern—the alarm created by the failure of 38 witnesses to report