In societies that regard some races or ethnic groups of people as dominant or superior and others as subordinate or inferior, hypodescent refers to the automatic assignment of children of a mixed union to the subordinate group. The opposite practice is hyperdescent, in which children are assigned to the race that is considered dominant or superior. Attempts to limit (or eliminate) mixed-race populations by legal means are defined in anti-miscegenation laws, such as passed by various states in the United States.