While children are dogs---loyal and affectionate  --teenagers are cats.  It's so easy to be a dog owner. You feed it, train it, and boss it around. It puts its head on your knee and gazes at you as if you were a Rembrandt painting. It bounds indoors with enthusiasm when you call it. Then around age 13, your adoring little puppy turns into a big old cat.  When you tell it to come inside, it looks amazed, as if wondering who died and made you emperor. Instead of dogging your doorsteps, it disappears. You won't see it again until it gets hungry--then it pauses on its sprint through the kitchen long enough to turn its nose up at whatever you're serving. when you reach out to ruffle its head, in that old affectionate gesture, it twists away from you, then gives you a blank stare, as if trying to remember where it has seen you before. You, not realizing that the dog is now a cat, think something must be desperately wrong with it.  It seems so antisocial, so distant, sort of depressed. It won't go on family outings. Since you are the one who raised it, taught it to fetch and stay and sit on command, you assume that you did something wrong.  Flooded with guilt and fear, you redouble your efforts to make your pet behave. Only now you're dealing with a cat, so everything that worked before now produces the opposite of the desired result.  Call it, and it runs away. Tell it to sit, and it jumps on the counter. The more you go toward it, wringing your hands, the more it moves away. Put a dish of food near the door, and let it come to you.  But remember that a cat needs your help and your affection too. Sit still, and it will come, seeking that warm, comforting lap it has not entirely forgotten. Be there to open the door for it. One day your grown-up child will walk into the kitchen, give you a big kiss and say, "You've been on your feet all day.  Let me get those dishes for you. " Then you'll realize your cat is a dog again. What is the chief purpose of writing this passage?
To tell us how to raise pets like cats and dogs. To tell us how a dog changes into a cat. To tell us the similarities between pets and children. To tell us how to deal with teenagers aged 13 or so.