People are fascinated by chimpanzees and monkeys because they can seem so human. This is one reason why many people have tried to keep them as pets. Even if they're gentle their whole lives, chimps and monkeys may turn violent out of instinct at some point, and people have been severely injured by chimps and monkeys acting out. Readers find out the fundamental differences between people and their fellow primates. These disparities highlight why it's unwise and even cruel to keep chimps and monkeys as pets.