Oppositional children is something I know all about. I was and still am to a degree oppositional to authority figures, and even close family and friends, when they try to tell me what to do.
Now as an adult I have children who grew up to be oppositional as well.
What can a parent do about this? Well if they are rich, they can hire a nanny to smarten the kids up, or send them to a school that will let them know whats up.
Unfortunately, the greater population is not rich and face obstacle of child rearing all on their own. Without outside help.
I think that a school is the best bet for any kid who has this kind of attitude. I look back and wish that I could of went to a place that taught respect and gave guidance to the reality of life. I know I would be a lot better.
The reason I say this is because most defiant children that are constantly opposing authority are children who learned from early childhood that it is okay to challenge parent's. This is not to say that that a parent's intentions are not good.
Many parent's don't like to see their kids hurt, so they cater to their opposition by giving in and making the child happy. This in turn teaches a child that it is acceptable to question authority, when in the home it is not being displayed.
Some kids just have it in their nature, but the majority of children's problem of excessive defiance comes from the people who nurtured them growing up.
So for the poor families, the tradition goes on, the kids oppose authority, have a hard time in school because of the behavior, and end up on the statistics as another low class household. Which could be a reason that the poor stay poor and the rich get richer. It is almost as if there are different breeds of mankind.
The elites have more access, and the funds to prepare their children for a successful future.
Of course different situations come into place and some kids who are defiant and have it bad, dig far and deep to find themselves a place where they can be successful. And some of the people who have it good can't get anywhere cause they can't find their place.
I would have to say through experience that if your kid is so far gone that you can't control them, try to help them fast. Some of these kids will even oppose help, and if that is the case, you just do what you can to make them happy in their current living situation, set rules and stick to them.
Consistency is usually where a parent with type of child find the rewards of a greater respect. And remember, it doesn't happen overnight. If you are a screamer, calm down and train yourself to talk. Nobody listens to a screaming maniac who is putting them down for their behavior.
It is possible to reform your oppositional child.