The Helpful Bystander: Current Evidence from CCTV-Captured Public Conflicts
Taken together, these data offer compelling evidence that bystander intervention is the norm in public space conflicts. Addressing the question of bystander helpfulness with CCTV video data, Levine, Best and Taylor (2011) assessed the de-escalatory and escalatory actions of bystanders across 42 public assaults. With evidence now suggesting that intervention is helpful from the perspective of the victim, the next question is whether such behaviour is potentially dangerous for the bystander.
Source: discoversociety.org