If something demands action, would you help? Or does it depend how many people are there...? We have fun talking about this controversial phenomenon.  Widely accepted to be true, contemporary research brings it into dispute. 

Sources:

Bystander effect in street disputes questioned:
https://nscr.nl/en/bystander-blijkt-wel-degelijk-in-actie-te-komen-bij-ruzie-op-straat/

Death of Raymond Zack:
https://www.firehouse.com/home/news/10722848/family-of-raymond-zack-sues-alameda-city-and-county-in-death

Kitty Genovese:
https://www.simplypsychology.org/Kitty-Genovese.html#:~:text=This%20term%20was%20coined%20after,intervene%20or%20call%20the%20police.