For me the limit is far earlier than ten. I expect as young as 4 or 5 a child to be learning basic etiquette and how to behave in public. This goes too for the ability to hold a conversation. I think it comes from when a parent is more concerned about being their child's best friend than being a parent - which means instilling responsibility, discipline, and accountability.

I find myself cringing as my anxiety level rises when I see children behaving like idiots in public situatons. I'm talking about places like art galleries, museums, theaters, and the like. When they are visiting someone's home for example I expect them to be 'on their honour' and respectful of the host's home and belongings. Again, 4 or 5 is not too early to instill this.