They probably were just like "Jason", all the killing raised their dopamine levels so they became high, I see them as ancient drug-addicts.
Imagine that someone from our time, time traveled back to that time, I guess it would be extremely hard to just survive one or a couple of days
wherever you went, like being in the midst of the psychopath's paradise.
Either they would see you as weak, then not worth to be living, or they would see you as strong, a threat not worth letting live, or they would notice that you are smart, making them feel stupid, so you must die,
or they would see you as stupid just worth to be played to death with,
or you happened to just look at them in a funny way, or you did not respect them by trying to not look at them, whatever, you must pay with your death. Anyone that were not born and raised in their way, would have extremely hard just to survive, so what happened was that people gave each other gifts all the time, in hope that that would let them be.
No one would go inside a tigers cage without having something to bribe the tigers with, without distractions, you are dead meat. Then they also lived by idiotic codes of honor, if you made someone loose their honor, they just had to revenge and how can anyone know before how somebody else will react afterwards?
Speech is silver, silence is gold, or, people had surely more reason to regret something they said or did than something they never said or did at all. I really do believe it's a wonder that anyone from those cultures survived at all.