We had a group of people at the same time, because people have to rely on to live. Without the facts above, we will find that living in a single die is very difficult. Therefore, the answer to this problem is to use live together as a group in which the group is very large, it is referred to as society 7. The main reason is to: 1. for security reasons, 2., 3., to power in order to achieve the goal. 4. in order to focus on reputation, 5. therefore, the cause of these kinds of things, it's necessary to have social norms that are shared.