Some trivia,
the severity of the physical punishment appearantly corelates with the belief system with the parents according to some studies according to a study. Perhaps I can find the article that documents this, but it's not really that surprising.
According to the abstract from
this article from 1991, more than 90% of parents in the USA use physical punishment. It also suggests without empirically concluding that parents who do not use physical punishment have, on average, better behaved children and that such punishment, while a good way to force conformity early in life will tend to cause deviating behaviour when the children grow up. Thus, a way to help minimize crime in a society could be to ban physical punishment.
I'm sure lots more studies have been made on this since 1991, so I'll see if I can find some proper empirical conclusions.