I never spanked. When very young, we used time out, then transitioned to talking about-and using-consequences. All actions have consequences, good or not good. Don’t want to do your homework? Ok, go to school without it; go on to bed now. You want to do the dishes? Cool, there will be a reward.
As the kids got more mature, they experienced in the real world that it’s best to do the right thing, do it first, and do it well. They still thank me for it, at 37 and 38.

I'm not a parent, but it's always seemed to me (based on my experience of other children's behaviour when I was a child and the behaviour of the children of my friends who are parents) that children who are subjected to spanking and similar forms of physical punishment learn only that it's acceptable to be violent towards someone who displeases you. I remember in particular two boys who lived in the same village I lived in as a child who were beaten with a cane by their father when they misbehaved; this absolutely failed to persuade them to be better behaved and they became more and more violent as they got older. One of them hit my then best friend Sarah in the face with a glass bottle and broke her nose - he was 14 at the time and thus very capable of understanding his actions; Sarah (and me) were 10.

On the other hand, those children whose parents used time out and then explained to the child why their behaviour had met with disapproval seem to have responded far more positively. I do understand that many parents, especially those who were themselves hit as children, may sometimes lash out - kids can be infuriating little bastards, after all; however, if I ever do become a parent (which is fairly unlikely now I'm 45), I'll avoid physical punishment at all costs.

Depends on the kid. Children should receive the most efficient and effective punishment based on what works. Most people don't provide effective consequences.

That was then but now things are different among responsible parents. Besides, spanking is an easy way to deal with problems. Unfortunately, it often sends the wrong message.

I have to echo what other posters have said. Spanking does not necessarily equal Good Kids - there are other factors involved, social, cultural, environmental and genetic.

Corporeal punishment runs the risk of having to escalate over time. When a spank isn't enough, it becomes a slap. When the slap ceases to be effective, it becomes a hit. And so on.

Negative reinforcement has the advantage of an immediate and understandable effect. My personal view is that such punishments are ultimately self-defeating.

Time outs, positive reinforcement and non-physical means of discipline take more work and time, but I believe are more effective at churning out productive and cheerful law abiding citizens.

Mind you, I have no kids (by choice) so my opinion here is largely worthless. However, I was a child once and I do not recall ever being struck when I was young. I'd like to think I turned out OK.

Consistancy matters. Any form of discipline can be useful, useless or outright abusive depending on how it is implimented.

For the most part spanking is the easy way out to me. Instant results but less real learning. Fear of physical violence will certainly make people "respect" you but won't necessarily instil real values and usually just teaches people to keep their mouths shut. That could be interpreted as manners and respect.

IT is not a black and white duality. There are other options beyond spanking or time-outs. Like denying privileges and earning back privileges for good behaviour (ie cell phone or internet use). Spanking does NOT teach respect, it teaches FEAR of the parent. And teaches one to resolve their problems with violence. They have good manners in spite of the abuse, not because of it.

My son (36) is very respectful and has excellent manners, he was never spanked or hit by either his mother or me. He carried a 4.0 through HS, graduated Summa Cum Laude with his BS and had a 4.0 on his Masters. Violence was never an answer. We didn't use time outs either, simple reason, logic and being involved.

Their behavior is not necessarily a result of your punishment style, as many other factors could have been involved. Like @sweetcharlotte, I don't believe in physical force to punish a child.

How did that make you feel?

If you'd beat one and not the other as a control in the experiment, your results would be much more valid. Still extremely limited and no way to account for the mother's own discipline, though.

Depends on the kid.