Some countries and indigenous tribes allow individuals to obtain citizenship based on their genealogy. In Ireland and in Greece, for example, an individual can become a citizen if one of their grandparents was born in that country, regardless of their own or their parents’ birthplace. In societies such as Australia or the United States, by the 20th century, there was growing pride in the pioneers and nation-builders. Establishing descent from these was, and is, important to lineage societies, such as the Daughters of the American Revolution and The General Society of Mayflower Descendants.
Private individuals research genealogy out of curiosity about their heritage. This curiosity can be particularly strong among those whose family histories were lost or unknown due to, for example, adoption or separation from family through divorce, death, or other situations. In addition to simply wanting to know more about who they are and where they came from, individuals may research their genealogy to learn about any hereditary diseases in their family history.