I've ghostwritten two books by members of a religious group that cited the spare the rod verse as a reason to deal harsh punishment to their children. The attitude was this: It's not the child that's misbehaving, it's a demon and you need to drive the demon out.
One of my clients related how one mother despaired of ever being able to hit her child hard enough to drive the demon out.This came up during a discussion with church leaders about what implements (rods) to have in the "lounge" for mothers to hit their children with. Hairbrushes, wooden spoons and rolled up newspapers were most favored.
Corporal punishment's popularity waxes and wanes, but it is something that many of us take for granted. In the Baha'i writings we are instructed never to strike our children. A Baha'i psychologist giving a lecture on this in San Francisco years ago answered a question from the audience: "By striking," the woman asked, "does Abdu'l-Baha mean spanking?"
The speaker blinked, smiled, rolled his eyes and said, "Only in California." He got a good laugh and the mom got the point without to much embarrassment. But for Baha'i parents it raises the issue of what to substitute if you grew up thinking of spanking as part of your repertoire.
I was spanked rarely as a child, but my mom had a tool that was even more deadly -- THE LOOK. THE LOOK said, "I am disappointed in you."
The Baha'i writings make a point that in a society in which God's laws are written on our hearts, the contemplation of a wrong is its own punishment (for adults as well as kids). I can attest that as I have tried to live the exhortations of my faith, I have become sensitive to some "sins" to the point that merely considering them brings swift remorse.
For a child, I think that threat of disapproval from a beloved parent has the same weight. My youngest child is especially strong-willed and, at six, a bit self-centered. Nothing modifies her behavior faster than when it sinks in that she's hurt Mom's feelings.
None of my kids have EVER been spanked and though they do things from time to time that make me cringe, other people seem to think they're the best-behaved kids they've ever met. I have no idea how that happened