Hi I'm doing research on some data which contains information on children and their parents. I would like to create an ID number for each family/entity. The tricky part (or at least for me) is that children should be given the same ID number if they are somehow linked through their parents. As an example the six children below (A1-A6) should all be given the same ID number, as (1) the first four children (A1-A4) have the same father, (2) A5 is a halfsibling to A4 (they have the same mother) and (3) A6 is a halfsibling to A5 (the have the same father)     Child ID, Mother ID, Father ID A1, Y1, X1 A2, Y1, X1 A3, Y2, X1  A4, Y3, X1 A5, Y3, X2 A6, Y4, X2   I hope someone can help me figure this out. Thanks!   ... View more