Kinship terminology is the set of words a culture uses to classify relatives. English has a relatively simple system: mother, father, sister, brother, aunt, uncle, cousin. Other languages make distinctions English ignores. In many societies, your mother's sister is called by a different term than your father's sister. Your cross-cousins, the children of your mother's brother or father's sister, may be distinguished from your parallel-cousins, the children of your mother's sister or father's brother.

These terms are not just labels. They encode social rules. If you call someone by the same term you use for your mother, you may owe her the same respect and care. If you call someone by a term that implies joking distance, you can tease them in ways you would not tease a parent. Anthropologists use terminology to reconstruct marriage patterns, descent rules, and residence practices.

Classic systems

• Hawaiian: lumps many relatives together.
• Eskimo: distinguishes nuclear family from other kin.
• Iroquois: merges mother's sister with mother.
• Sudanese: distinguishes every relative separately.

Kinship terminology is a window into how a society organizes its most basic relationships.