A person who was born into or legally adopted into the direct line of an individual’s descent (e.g., children, grandchildren, and great-grandchildren). Such a person is also called a lineal descendant, “direct” descendant, or “offspring” descendant. A spouse, stepchild who has not been adopted by the stepparent, parent, grandparent, brother, or sister of an individual is not a descendant of that individual.
The terms “descendant” and “heir” are sometimes used interchangeably, but they are not synonymous and their misuse can result in unwanted consequences.
Heirs are those individuals who, by operation of law, inherit the property of a decedent who dies without leaving a valid will. Though state laws vary, an heir will typically be a spouse, child, grandchild, or more remote descendant, or a close relative such as a sibling, niece, or nephew. This means that although descendants are typically heirs, heirs often include individuals who are not descendants.
This difference is best explained with an example:
Grandmother has two children: Abigail and Betsy. Grandmother provides for her children in her will as follows: “To my children, in equal shares, but if a child predeceases me, then the deceased child’s share shall be distributed to that child’s heirs.” Betsy predeceases Grandmother, but Betsy leaves behind a spouse, Hank, and three children.
Under Grandmother’s will, Betsy’s share would go to Betsy’s heirs. Under the laws of every state, Betsy’s heirs include her spouse; and under the laws of many states, Betsy’s heirs would also include her children (Grandmother’s grandchildren).
Although it is possible that Grandmother wanted to provide for her son-in-law, as well as for her grandchildren, that is not the result many people would want. The majority of people want to provide for their children and grandchildren, but not their children-in-law.
If Grandmother’s will had instead specified that a deceased child’s share should go to that deceased child’s descendants, the result would have been in line with most people’s wishes—to provide for their children and grandchildren.