I once read a great article, written by a priest, about the "sparing the rod" bit, and how certain circles have long used this verse to justify corporal punishment. He wrote that in biblical times, many people were shepherds, and they called the staff a rod, or at least it translates that way. The shepherd doesn't hit the sheep with the rod, it is intended to guide. The verse is really saying "spare your child guidance (training if you will), and the child is spoiled." makes sense to me. I had the article bookmarked on my old pc, wish I could find it. I can speak from personal experience that sparing my child a spanking certainly did not spoil them. I am fairly sure my eldest is the most well-behaved person I know, and spanking has never been part of our parenting plan, perse.
It boils down to this, parenting is hard and there is no perfect way. Most of the time, spanking is an emotional reaction by the parent (angry/ frustrated/ embarassed), not a parenting strategy. If a child is not old enough to control their excrement and understand the bathroom must be used to relieve themselves, how in the world are they supposed to understand that mommy/ daddy hitting them is for their own good/ lesson learned? That has never made sense to me.
I find many folks in the traditional crowd tend toward some very Dr.Spock/ Freudian beliefs about the bringing up of very young children. Not sure why, it certainly isn't church doctrine. As a matter of fact, the most distracting thing I encounter at mass is the harsh (HARSH) treatment of very young children by their parents. I cannot fathom how one can be so near God, surrounded by statues of the Blessed Virgin cradling her Child, and still show a literal baby such nastiness. Our Blessed Mother is an example for us as parents. Just three weeks or so ago, a baby under one was spanked right in front of me for crying. He was not able to talk. Crying is a baby's communication, not a personal jab at a parent. Also, the silly "mouth-slapping" parents do with babies babbling. That baby has no clue why mommy is popping their little mouths, they do not have reasoning skills enough to figure that out. Most people at mass are parents, grandparents, aunts/ uncles, brothers/sisters. We are all used to baby noise. The sound of a little baby babble or a sweet toddler question is much less distracting than the hissing, swatting, spanking, slapping, pinching melodrama I see so often played out.
I also think there is a lack of understanding what "age appropriate behavior" means. I also think some parents spank in public and do nothing about boundary-setting at home. So sad.
All that said, I know we all must parent the best way we know how. I just wish more folks would learn and try other ways before going right to spanking. Spanking is not for everyone, just like I know not-spanking might not be for everyone. I do know that I take much time reading and preparing for my parenting decisions, and we all owe it to our children, families and selves to do the same.