They are not speaking of seriously harming the child.
My parents beat me with a switch on my legs when I fell out of line. But not for small infractions.
I ended up on the straight and narrow. lol. Didn't talk back, didn't have boyfriends, finished high school, went to college, became a cop, married, had a kid..etc..lol.
I work with youth now...and I can always tell the ones who don't get beatings. There are many of them...and they are very rude and disrespectful. Spoiled brats.
I have only met a select few kids who had self discipline and their parents didn't beat them.