Final answer:
It is false that unilineal descent is commonly practiced in the United States. Most Americans follow a bilateral descent pattern, tracing ancestry through both parents. While certain patrilineal practices exist, like children taking their father's surname, they don't define the societal norm of descent.
Step-by-step explanation:
In the context of social structures in the United States, it is false that we commonly practice unilineal descent. Instead, most people in the U.S. practice what is known as bilateral descent, where individuals trace their lineage through both the mother's and the father's sides of the family. Although certain aspects of U.S. society may lean towards patrilineal practices, such as children often assuming their father's surname, we do not follow a unilineal pattern as a societal norm.
Unilineal descent is characterized by tracing one's kinship through a single-gendered line. This form of descent is common in some other societies around the world, particularly in pastoral cultures. There are three types of unilineal descent: patrilineal descent, matrilineal descent, and ambilineal descent. The first two trace lineage through either the father's or mother's side exclusively, while ambilineal descent allows the option to choose either parent's lineage based on different factors.
In contrast, bilateral kinship systems consider relatives from both the maternal and paternal sides as part of one's family. This system is followed by the majority of modernized nations, including the United States. The diversity of family structures, such as blended families, further supports the bilateral approach to lineage and descent in American society.