You know this far better than I, surely, but isolation and hatred are not new problems in human society. However, I think it's hard to really argue that hatred and isolation are now much, much more common.
I think the presence of visual imagery provides a mimetic response, aka mimetic the greek word for "imitation" where we get the English words mimicry and memes.
TV and Internet changes the mimetic response of mimicry for the visual signfier is in our faces and we can learn about things 5 to 25000 miles away in real time.
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That said other cruelties used to exist in the past that are less frequent (they still occur.) A mob is a form of mimetic group psychology which is not like humans thinking as individuals. When a mob becomes a pogrom, lynching, or witch hunt I hope is less common in today's society. (still happens)