[Tasmanian Saint]

I've read only the first two pages of replies, but wanted to say,

I didn't really realise spanking (well, hand-slapping) wasn't working until I stopped It's partly what some others here have said: seeing what I wanted to see. It's also that it did 'work' (stop the undesired behaviour) *some of the time*.
I started reading about clicker training about the same time I discovered GD (unrelated, just coincidence) and they talk a lot about behaviourist models (of course - they're animal trainers). So you can encourage a behaviour by using rewards or punishments, but the *most effective* way is to use 'intermittent rewards'. Generally they wouldn't try to teach this to an amateur trainer, though, 'cause it's not easy to get right, and continual rewards works perfectly well.
The thing is, when my son was *sometimes* responding to punishment the way I wanted, that was giving *me* intermittent reward for the hand-slapping - thus encouraging me to keep trying to figure out how to make it 'work' all the time - but I believed, and would have said, that it was working