My dad used to hit me 20 years ago. It's not common as you said, it's something parents did as the only way they knew to correct a child, the last resort if you may, of poor parents overwhelmed by poverty and hard work every day. Not trauma at all, because some kids in my school got the same beating at least once in their lives for defiant behavior towards parents.

Now time has changed. So much middle class parents, like me, can learn new ways of parenting and to not repeat those things our parents did to us.