It is proven over ages in all cases.....including killing other tribes from their patriarch Ibrahim's times.till Saddam killing Kurds and presently shia vs sunnis all over the the world's muslim pockets.
Anger seems to hve become almost a genetic quality as in every incident they feel they are wronged....and the result was redressal through physical manifestations skirmishes and wars of sword and horse/camel.
May be that is that kind of civilzation !
Humanity has gone through so many adversities but the wiser have put up with them with patience and solved them in a humane way.
