People of the Northwest Coast often lived in villages divided into two groups, called moieties (MOY-uh-tees). Each moiety was composed of clans. A village might include two or several clans. The members of a clan considered themselves related because they shared the same spirit ancestor.
Clans were part of larger groups called phratries (FRAY-trees). Their main purpose was to oversee marriage rules and provide aid. People from the same clan, moiety, or phratry could not marry.
Each clan had three ranks of people: nobles, commoners, and enslaved people. Nobles were the richest members of their clan. Commoners were respected clan members, but with less wealth than nobles. Families could gain or lose social standing by increasing or losing their wealth. The enslaved people were captives from other villages. They could not change their social standing. Usually, several related families lived together in a plank house, which was owned by the wealthiest man.