off track from this a little..
i've been thinking of this concept a lot lately, this idea of how society can get completely convinced that something so insane and cruel like slavery is the right thing and an economical boost and it spreads globally. The only large communities who fought for the freedom of slaves early on were the pirates. It took a long time for people to come to a realisation that slavery was so messed up.
The other idea is extreme cruelty during war. most people don't go around shooting everyone randomly, raping women, forcing children to shoot their parents. The RUF rebels in Sierre Leone did this in the name of recruiting child soldiers and this kids who were so innocent become wrapped up in this cruelty and it replicates.
In the book Tipping Point by Malcom Gladwell, he talked about a suicide trend in South Pacific islands of Micronesia. Prior to it, it was unheard off. And then one young teenage boy committed suicide because of some problems he had with a girl (or two girls) - and eventually it became cultural. Arguments with parents and the kids commit suicide
And you see this similar pattern through the influence of Bollywood movies and the rise of emotions. The influence normalising drugs usage and selling among black kids. The list goes on and on
It's so easy to get trapped into a "cultural" bubble. Scary even