Humans are fascinated with violence

Look at our movies, they are full of blood and violence. Look at the combat sports we enjoy, the crowd goes berserk when there's blood or if someone gets knocked out. These serve as an outlet for our suppressed violent selves.

I think this ties back with the way humans became apex predators, our ancestors were violent. Depends on what you classify as violence, it was a way of life in ancient times. It wasn't a choice - you either hunt or be hunted. Look at the wars we have fought over the years. How many people were massacred. Even now we have so many weapons of mass destruction that is enough to kill everyone on the planet possibly multiple times.

Such is the nature of humans. When humans are incapable of expressing this violent self, the resort to other ways to hurt and hunt others - such as manipulation or deceit. You may want to punch your coworker, but you cannot so you must resort to passive aggressiveness, rude responses over email or think of ways to fuck up their career through escalations to superiors — all while maintaining corporate etiquette.

Such is the nature of humans, we are all animals at the end of day with a bit of self control.

When all hell breaks lose, you see what we are capable of, even the most civilised will commit atrocities.