I remember watching the beginning of an X-Files episode when I was probably just a little bit too young for it. It kicked off by showing this group of young kids (my age or a touch younger) in a playground during recess when a swarm of bees descended on everything. Everybody but one kid had managed to run inside (where, miraculously, no bees decided to follow). This kid had succumbed to the stinging swarm and fallen to the ground trying to ward them off. Everyone, now inside, watched in horror and made no move to help.
That was the first time I found out that people don't have an innate desire to help someone who's suffering when they themselves will be put at risk. And for my tiny little self, it scared me to know that I had already been living in that world and always would be.