There's a difference between beating/spanking as discipline vs. as abuse (very subjective tho). It's one thing to give out a few swats on the ass to make sure the 3yo knows not to play with the knobs on the gas stove or stick things in electrical sockets, it's a whole other thing (like abuse) to smack the shit out of your kid because they got on their parents nerves or forgot to clean the mess up in the kitchen.

Personally, I think physical discipline has a place (a very small place, like a slap on the hand, a pinch or swat on the ass). A lot of what happens in reality is straight-up abuse tho. No reason to smack your kid in the face, strike them with a closed fist or not use reason and some other form of discipline in the first place once they are able to understand (4yo?).

I don't think physical discipline is a throwback to slavery, but I think the overuse and abuse of it is.