This has to be sarcasm. You don't have to look that far back to know that this is just untrue. There are ethnic cleansings and organised genocides everywhere (regrettably), with very little evidence it has something to do with a specific type of culture.
Would the early United States be considered an "individulistic society"?
If so then consider the continental level genocidal practices which that society consciously adopted. Remember that all of North America was populated before the westward expansion. Feel free to extrapolate backwards in time.
The early United States was on the way to being an individualistic society, but hadn't arrived. In particular the natives who they killed they saw as part of a group, and not as individuals.
There is a long and complicated history in English speaking people of "rights for me, but not for thee" which started with the king, was broadened to nobles with the Magna Carta, was broadened to rich landowners with the establishment of Parliament, was in the process of being broadened to free white men around the time of the American Revolution and has piecemeal been given to other groups over time.
What today we consider "universal rights" were historically not universal. Our awful treatment of others is tied to our not granting rights to them. And our awful treatment of ourselves (for example in totalitarian societies) is tied to our being subsumed in something greater.
some of these countries have become so good at institutionalizing injustice via their privatized prison systems that this form of ethic cleansing is not even visible any more with the naked eye.
When a large group of your population is unable to financially afford justice that's a form of ethnic cleansing.
Genocide is horrible, but what could possible be more evil? Here is what: masterminding it so that a large group of your population no longer sees it for what it is and would rather point at another country for its concentration camps than solve their issues at home.
> but you don't tend to get ethnic cleansing or organized genocides.
How would you describe the US private prison system, or gitmo if not "organized genocide"?
Is it though? I don’t think I’ve found more individualistic societies to be less racist or nationalist.