This is really tough. I'm sorry. I would definitely have them evaluated. I have read (and experienced) that sometimes we allow adopted kids to "get away" with things because we worry that their behavior came from some deep seeded problem caused by something in their adoption. I've also read the same thing about children of divorce.
So, if we believe that these things came from some disturbance they have experienced, we need to get professional help.
Professional help with assist in distinguishing between what are the discipline issues (and how best to deal with them) and what are those deep seeded problems (and how to deal with those).
Make the appointment today! Good luck.
