Final answer:
In a bilateral descent group, everyone is a relative as kinship includes both the mother's and father's lines. Unilateral descent, by contrast, traces kinship through one parent's lineage only and includes patrilineal, matrilineal, and ambilineal descent types.
Step-by-step explanation:
In a bilateral descent group, an individual is considered related to family members from both the mother's and father's sides of the family; therefore, all persons in this group are relatives. Bilateral descent is the practice of tracing an individual's kinship through both parents' lineage and is the most common form of descent in the United States. It contrasts with unilateral descent, where kinship is traced through only one parent's line. There are three types of unilateral descent: patrilineal descent which follows the father's line, matrilineal descent which follows the mother's side, and ambilineal descent which depends on the family's choice of either the mother's or the father's line. For example, if a child associates their line of descent with their father's side only, this would be a patrilineal descent, not bilateral.