Social relations and presence of others predict bystander intervention: Evidence from violent incidents captured on CCTV.

Are individuals willing to intervene in public violence? Half a century of research on the "bystander effect" suggests that the more bystanders present at an emergency, the less likely each of them is to provide help. However, recent meta-analytical evidence questions whether this effect generalizes to violent emergencies. Besides the number of bystanders present, an alternative line of research suggests that pre-existing social relations between bystanders and conflict participants are important for explaining whether bystanders provide help.