The splintering into groups, the otherization of "not us", has existed for a very, very long time. Chimpanzees brutally murder other groups of chimps, females a

The splintering into groups, the otherization of "not us", has existed for a very, very long time. Chimpanzees brutally murder other groups of chimps, females and children alike, and they have even been seen eating their enemies' corpses raw. For Homo Sapiens with Neanderthals, we suspect they both inter-mingled, shared genetics via sex, as well as brutally attacked Neanderthals. Is it surprising that, along with mega-fauna and easily killed prey, Homo Sapiens seems to have killed many Neaderthal groups as well? Is this that surprising, then, when Homo Sapiens attacks other groups of Homo Sapiens? When humans have seen those evil "others", it usually leads to violence and domination by one party. Look at colonization of the Americas, enslavement, genocide, justified by religion, profits, "self defense," manifest destiny -- any excuse will do if it's just "the others." So, from a historical and biological lens, I'd say current echo chambers are not surprising, they're an extension or outgrowth from very ingrained biological reactions.