"In it's function, the power to punish is not essentially different
from that of curing or educating."
- Micheal Foucault
I believe spanking is administered to punish, teach and instill self discipline in order to raise a well mannered, socially adjusted, successful individual.
One of the first lessons a child learns is to obey authority, for it's own sake and without explanation. In other words, "...because I said so." In time, they will come to understand the reason why playing on the train tracks, or wondering off alone is a punishable offense. The spanking was done to keep the child safe.
Still a child will test authority and a mother who makes threats, too often, to spank her child, will begin to lose authority. She is (unconsciously) sending a message that she's not to be taken seriously.
But the most absurd method of behavioral correction of all, is to reason with a young child in the throws of a tantrum. How many times have we seen a child of five or six screaming and flailing around, while the mother attempts to "reason" with him as though he were fourteen? Of course, this accomplishes nothing more than to make the child even angrier and more aggressive; and sometimes enough to give her a kick in the leg. Here's why.
Children have a need to feel safe and to know that the woman in control of their lives is strong and able to protect them. For this reason, instinctively, they will test and if she is easily intimidated, they feel threatened by, and vulnerable to world around them.
By the same token, if a child acts out in public and the mother pulls him off of the floor and spanks his bottom - then and there - he eventually calms down. The reason is the same. He knows he's in strong capable hands; boundaries will not be crossed; and he is safe. The same holds true for adults.
Grownups act out too, although (hopefully) in more subtle ways.
They test the boundaries, procrastinate, fib, sass, throw tirades and indulge in various other willfully, unacceptable behaviors.
Adults need to be reminded that there are consequences to paid when they do things that are potentially harmful.
I am a firm believer, that a good, old fashioned spanking to tears and little beyond - is effective discipline at 6 or 60.
In my experience, children of any age, must realize they are to behave and know that they're in the hands of a strong and capable woman.
The more things change, the more they remain the same.