I was reading an article about spanking, and it made a very silly argument, it said that once comprehension has been established, corporal punishment is never necessary. Now, one can assume that adults have established comprehension. However, even though they know that it endangers themselves and others, that they can have their privileges taken away, that they can be given a time out, and that their allowance can be reduced, adults still drive drunk. Comprehension has been established, and it does not eliminate a profoundly harmful behavior. I bet if you flogged people for driving drunk you'd go a good ways towards eliminating it, but their argument doesn't hold water regardless.