Social network
How big a personal network becomes depends on the individual and the type of relationships considered. The set of people that a person knows well or with whom a person frequently interacts seldom exceeds several hundred. As the size of a network grows, keeping relationships is strained by the size. There is a so-called "Law of 150" which suggests that about 150 people is the best size for a village or large clan though most people live in much bigger towns. Some experts think that a corporation has an ideal size of about 70 people: these people and their spouses would also make a large social network.