Prohibited Degrees of Relationship
Tennessee law defines prohibited degrees of relationship for marriages, generally considered "incestuous." Marriage cannot be contracted with a lineal ancestor (parents, grandparents, great-grandparents, etc.) or descendant (children, grandchildren, great-grandchildren, etc.), nor the lineal ancestor of either parent (grandparents, great-grandparents, etc.) or descendant of either parent (brothers, sisters, half-brothers, half-sisters, nieces and nephews, grandnieces and grandnephews, etc.), nor the child of a grandparent (aunts and uncles), nor the lineal descendants of spouse (spouse's children, grandchildren, stepchildren, step-grandchildren, etc.), nor the husband or wife of a parent (stepmother, stepfather) or lineal descendent. T.C.A. § 36-3-101. A marriage entered into in violation of this statute is void in Tennessee regardless of whether the marriage was entered into in Tennessee or in another state where the marriage would be valid. Rhodes v. McAfee, 224 Tenn. 495, 457 S.W.2d 522 (1970) (declaring void the marriage of a stepdaughter to her stepfather after the divorce of the stepfather and the mother). In an opinion dated October 24, 1960, the Tennessee Attorney General determined that this statute does not prohibit marriage between first cousins.
Effect of Adoption
The signing of a final order of adoption establishes the relationship of parent and child between the adoptive parent and the adoptive child as if the adopted child had been born to the adoptive parent, and the adopted child is deemed the lawful child of the adoptive parent for all legal consequences and incidents of the biological relation of parents and children. T.C.A. § 36-1-121.