My question in response is, "is that qualitative difference also qualitative?" I'm starting to think I agree, as long as you extend "scarcity" and "harshness"

My question in response is, "is that qualitative difference also qualitative?" I'm starting to think I agree, as long as you extend "scarcity" and "harshness" beyond the purely economic. Otherwise how do you explain what appears to be the majority of modern jihadists coming from at least the upper 1/2 of society, if not solidly middle class or above, e.g. the 9/11 hijackers? Of course, your thesis doesn't have to explain all examples of being "rutheless". As for your last point, hmmm. Is that in part a function of viewpoint, of e.g. the author(s) and audience(s)? ADDED: other counterexamples: The Japanese in WWII, the actions of some high caste Indians towards lower caste ones. (As a matter of fact, in India in the last few decades, while incomes have gone up, calories and quality of them has gone down for those lower on the socioeconomic scale...).