Abstract: Systems and methods are provided for determining relationships among individuals. The method can include receiving, from one or more sources, a plurality of records associated with a population of individuals; building a single database with the plurality of database records, each of the plurality of database records comprising a plurality of fields, each of the plurality of fields configured to include an associated field value; determining similarity among corresponding field values of the database records; producing a relationship database, based at least in part on the determining the similarity among corresponding field values of the database records; associating mutually matching database records; producing a relative database; and outputting database record information comprising a plurality of identifier pairs corresponding to individuals.