The bystander effect says we are less likely to help someone in need when others are present. But a new study found that 9 times out of 10, bystanders will intervene to help victims of aggression and violence. 

Researchers from the University of Copenhagen and Lancaster University reviewed video recordings of 219 disputes and assaults in the cities of Amsterdam, Lancaster, and Cape Town. They saw that in 91% of incidents, bystanders intervened by either physically gesturing the aggressor to calm down, pulling the aggressor away, or comforting the victim. 

Furthermore, researchers found that people were more likely to step in when many bystanders were present. 

This study shows that bystanders are much more likely to intervene than previously thought. Researchers say these findings can inform crime prevention efforts.


Philpot, R. Lienst, L. S., Levine, M., et al (2019, June 3). Would I be helped? Cross-national CCTV footage shows that intervention is the norm in public conflicts. American Psychologist. Retrieved from