What a lot of great advice you all have... some excellent ideas to help me with my own mouthy, argumentative 6 y.o. At first I tried explaining my reasons thinking that was what he wanted, but it made things worse. I think it did convey to him that my authority wasn't enough (thanks, Grinity). Now I've started to say, "I've made my decision - end of conversation" and then just stop talking. He doesn't like it, but I do think it may be working.
Also, we've started enforcing a time-out for yelling or using a rude tone -- not put in a corner with nothing to do, but in his room with a book or pen & paper or something else to redirect his thoughts. This helps him calm down pretty fast and he is ready to be nice again after a few minutes alone. My theory is that rather than punishment, he needs strategies to help himself deal with frustration. And if nothing else, it allows *me* some space to calm down myself... the constant challenging and arguing can be exhausting and maddening!
