Cats were likely domesticated more than 10,000 years ago, but despite their relationship with humans, they've maintained their wild nature in some ways, according to behavior expert John Bradshaw. "Cats can be very affectionate, but they are choosy," he writes. "This stems from their evolutionary past: Wildcats are largely solitary and regard most other cats as rivals." However, domestic living meant cats needed to develop a broader repertoire of social behaviors. Bradshaw discusses a number of them in this article, including why cats raise their tails and the importance of a meow.