Recently a specialist  in teenager studies does some research on teenage problems. He thinks parents shouldn't be blamed of themselves because there is nothing they can do to deal with the teenage problem. Whatever they do, sometimes a wonderful, kind and helpful child will turn into a terrible animal. I've seen friends deal with _ in all kinds of different ways. One strict mother insisted that her son, should stand up, open doors and shake hands like a gentleman whenever anyone entered the room. I saw him last week when I visited them. Lying on the sofa, he made no attempt to turn off the loud TV he was watching as I walked in. His mother was angry. "I don't know what to do with him these days," she said. "He's forgotten all the manners we taught him." He hasn't forgotten them. He's just decided that he's not going to use them. She said that she would like to throw him down from the sofa onto the floor. Another good friend of mine let her two daughters climb all over the furniture, reach across the table, stare at me and say, "I don't like your dress, it's ugly." One of the daughters has recently been driven out of school. The other has left home. "Where did we go wrong?" Her parents are now very sad. Probably nothing is wrong with the parents. This text is most probably written by  _  .
A specialist in teenager studies a headmaster of a middle school a parent with teenage children a doctor for mental health problems