my youngest is 3. It is very difficult to reason with a 3 year old. I don't for one moment think that my children are well behaved all the time and god, how boring they would turn out if they were! Children will never learn how to behave in social situations if they are not put in them, and personally I advocate taking children to restaurants etc. I don't however advocate bad behaviour. But bad behaviour is subjective. Some people might consider a child that is talking a little loudly to be badly behaved, but do you remember being a child and trying to make a point in a conversation, only to have the adults at the table ignore you? Again, children will never learn how to moderate their behaviour in social situations without practice.