By: Jonesborough Genealogical Society
Many people find the cousin relationship extremely confusing, so we’ll try to clarify it. Suppose that two people marry and have four children – A, B, C and D, each of whom has a child – A1, B1, C1 and D1, respectively. They have children A2, B2, C2 and D2, who have children A3, B3, C3 and D3, who have children A4, B4, C4 and D4. The children of the brothers and sisters (A,B,C,D) are first cousins – A1, B1, C1, D1. The children of first cousins – A2, B2, C2, D2 – are second cousins. The children of second cousins – A3, B3, C3 and D3 are third cousins, etc.
Things start getting confused when we get into the “removed” relationship – the non-direct kinship. For example, what is the relationship between A1 and B2? Go back to the closest direct kinship, which is A1 and B1, who are first cousins; B2 is removed one generation from B1; therefore, A1, B2 is removed one generation from B1; therefore, A1 and B2, are first cousins, once removed. Note that A1 would have the same relationship with C2 and D2, and B2 would have the same relationship with C1 and D1.
What, about B2 and D4? The direct relationship is between B2 and D2, who are second cousins; D4 is removed two generations; therefore, B2 and D4 are second cousins twice removed.
Let’s do one more. What is the kinship between B4 and C1? The closest direct relationship is between C1 and B1, who are first cousins; B4 is three generations from B1, so B4 and C1 are first cousins, thrice removed.
BROS. & SIS. A B C D
FIRST COUSINS A1 B1 C1 D1
SECOND COUSINS A2 B2 C2 D2
THIRD COUSINS A3 B3 C3 D3
FOURTH COUSINS A4 B4 C4 D4