The sound of silence: The importance of bystander support for confronters in the prevention of norm erosion.

Observing deviant behaviour can lead to 'norm erosion', where a norm is no longer seen as relevant and compliance with it is reduced. Previous research argues that social confrontations can mitigate norm erosion. However, this work has not considered the impact of bystanders to confrontations, who might influence the outcome by supporting-or failing to support-the person confronting a social rule breaker. We examine the effect of bystanders' reactions on preventing norm erosion across three experimental studies. We examined how supportive and non-supportive bystander reactions to a confronter impacted the perceived strength of a prosocial norm among participants and their behavioural intentions. We find that when bystanders explicitly supported the confronter against the rule breaker, the norm was perceived as stronger-and sometimes, compliance intentions were higher-than when bystanders did not respond to the confronter. A mini meta-analysis across the three studies reveals that the effect of bystander support on perceived norm strength is large and robust. Our work demonstrates that for the prevention of norm erosion, confrontations benefit greatly from being explicitly supported by bystanders.