Back in University a few Asian students told me about the beating they received as kids by their parents and in school. It wasn't harsh (according to them) just a painful motivator or, in most cases, used when they acted up excessively. It was more of a case of inducing good habits while discouraging the bad ones. In their cases the "motivation" stopped once they were teens because by then they were much more mature and had acquired good study habits and behavior skills. I guess it was a case of "spare the rod and spoil the child".
I think that sort of 'moderate' corporal punishment is the best method, because it teaches tact.
Children need to learn that, when they push certain limits, they are putting themselves in a dangerous situation.
Observing the children of parents that don't practice any corporal punishment,
it's clear that they will grow up to be spoiled brats with a sense of entitlement.
Unaware of the possible physical consequences of their haughty attitude,
they could be in for a rude surprise when interacting with societies more impulsive types.
Now of course there are many other factors at play here, when talking about psychological development -
genetic disposition being the most obvious.
Constant and severe beatings will just make you angry at the world.
In the case of the Asian/Indian students, they didn't grow up hating everyone,
because they were capable of recognising that the beatings they received were well deserved.