Behavior modification and token economies are effective for all kinds of people and all kinds of populations. They found it is very effective with even adults with a mental retardation. You can teach an old dog new tricks, so to speak. If you are using this with your child and you are finding that it is not as effective and you know you are being consistent with it, then you have to consider other circumstances which might be motivated by nutrition, health issues that they cannot articulate. That can motivate bad behaviors. You might want to get professional help. There might be another diagnoses that you haven't considered, where they might need a prescription for a condition that they have. You can look at other extenuating circumstances if you find that you have really been consistent and you are still seeing some troubling behaviors.