I really liked the Cambridge dictionary definition better:
ATAVISTIC – atavistic meaning: happening because of a very old habit from a long time ago in human history, not because of a conscious decision or because it is necessary …
That sort of sums up the world we are seeing these days. A world where behaviors and patterns of behavior from the past are overtaking modern civility. Although I’m pretty sure back in Rome, they were pretty civil even then. Our rough incivility and crudeness aren’t atavistic. They are merely crude.
I maintain that much of what is wrong with the world pertains to the way we treat each other. If we are kind, generous, and civil, the world remains a fairly well-oiled machine and it’s possible for everyone to hold their opinions without turning every disagreement into warfare.
These days, people seem to have forgotten the things we learned in elementary school. Like “please” and “thank you” and “excuse me” and most important, “I’m sorry.” Along with “no bother ” and “I forgive you.”
There’s no point in going on about this. Our world is becoming a crude and ugly place inhabited by people who would not be accepted in any civilized society, now or long in the past.
We aren’t being atavistic. We are simply ill-mannered.