It was acceptable in the 1950's 1960's and 1970's as far as I remember,. Many a child got a smacked bottom,or a small smack on the legs if they were acting up badly. at home, or out with parents. It usually did the trick, of quietening them down, and they usually didn't act up again.
I actually remember, that in those days. I don't ever remember seeing any small children who had melt downs, and tantrums all the time, and throwing things around the house, or kicking out at parents and other siblings etc.
I just remembered something funny though, I was in a Boots chemist in a town where i lived in mid 1970, There was Mum and two year old boy in the aisles. he was not wearing reins, and he was running amock all over the place. and getting all sorts of things off the low shelves, The Mother was running after him, and loudly shrieking at the child, she said come here you naughty boy, and caught up with him,, but he then threw himself on the floor, screaming and crying, legs kicking and rolling on the floor. he wouldn't stop crying,
The next minute,the Mum lay down on the floor, and mimicked exactly what her little son was doing, and some pretend crying too.. Immediately the little boy stopped all his crying, jumped up. and threw his little arms round his Mum, and said Mummy, why are you crying, are you alright.. Then he held hands with the mum., as she walked down the aisle and got a couple of things off the shelves,