Stages of Intellectual Development In Children and Teenagers (Child Development Institute)
As a parent of three and one that spent years volunteering in the public school system, as well as managed youth hockey teams, I've worked with children from birth to age 18. I can tell you that there is no reason for corporal punishment.As one who has never been a parent, I couldn't say for sure, but I have a hard time seeing the argument that corporal punishment is "necessary" for any reason at all.
Little children aren't bad, nor do they do bad things. Telling them they are only reinforces guilt and shame. They are inquisitive by nature and get into things perhaps they shouldn't, It's the parents responsibility to child proof their environment, not slap them when they touch something they should not. Soylent is also correct, that children will attempt to manipulate other humans to get what they want. It's up to the parent to avoid encouraging this kind of behavior and reward the positives, else the manipulative behaviors become part of their character .
Bad behaviors most often occur due to lazy, non existent, or inconsistent parenting. How do you think a preschool teacher is able to maintain discipline in a classroom of 12 kids? It's not by hitting them, I can assure you. Children love rituals and schedules and the rewards that come from adhering to them.
If slapping worked, you'd only have to hit them once but that's not the case. If an adult can't outsmart a child and has to resort to hitting them, who is the intelligent one?