Would you agree that is ineffective after a certain age ?

I would say maybe six or seven, although i do agree that smacking should be allowed i dont think it should be the first resort. I think if it is used too much it can get out of hand and can be over used or the child can be smacked too hard. I remember when i was just very sad about something and i was smacked which made me even more upset I(when i was about 5/6) so smacking isnt always the answer. Try and listen to what your children have to say and tell them how their behanvious effects you or others, they may be young but they arent stupid.