Summarize the following:
A cat will not always growl or hiss at you when it is mad or scared. An angry cat will have dilated pupils and stare at whatever it's angry at. The fur on it's body will usually also stand on end. The tail may also flick from side to side as it holds it in an upside down U. In addition, an angry or scared cat may have its ears flattened back. In contrast, a friendly cat will approach you with its tail up, erect ears, and rub against your legs. It may give a friendly meow or series of meows and may even be purring. Cats are affectionate and responsive creatures. To get your attention, cats will often sit close to you or brush up against your legs while meowing. This solicitation for attention is normal cat behavior. It places the cat's scent on the recipient, helps them bond with you, and probably, although we can't know for certain, has other significant meanings. When a cat rubs up on a human it's an important bonding ritual. If your cat is rubbing up against you, don't shoo it away. Let it give you a little love and attention so that This action, rubbing up against another animal to transfer scents and affection, is called allorubbing when done with another cat. This is one particular behavior that leaves some owners scratching their heads. Some cats will "paddle" or "knead" their humans. This behavior is a holdover from when the cat was a kitten. Kittens knead their mother's mammary glands as they are nursing to get the milk flowing. It is thought to be comforting for a cat to do so on a beloved human being. Kneading can get aggressive if your cat engages its claws while doing it. Be sure to protect yourself if you know that your cat goes overboard when kneading. Try wearing a long sleeved shirt or other protective clothing or have your cat stop when they start injuring you.

Summary:
Learn to identify when your cat is angry or afraid by paying attention to its body language. Understand why a cat rubs up against humans. Understand why your cat kneads.