Private ownership has existed since prehistoric times. Even animals observe private ownership, not just over their own bodies, which is self-ownership, but also

Private ownership has existed since prehistoric times. Even animals observe private ownership, not just over their own bodies, which is self-ownership, but also over their kills, and territory. The principle of First Possession, where other animals have a tendency to cede control over a resource to the first animal that comes to possess it, is widely observed by behaviorally advanced animals, and game theory experiments suggest it reduces conflict, which would explain why.