My son 12 years of age, has lost total interest in his studies. We have tried to encourage him that if he does his h. W then we can send him to drawing classes. We had send him for 1 month. But now his exams are going on. His father had asked him that if he gets good marks then we can send him again but I think this doesn't makes him encouraging to do work or study. Also he is very aggesivemostly and doesn't want to listen anything. please help. What to do?