The Generic Family Tree

Jonathan Coxhead ☺, 2002-01-07

Introduction

This is a ``prototype´´ family tree. Instead of the names of real people, each slot is filled by the name of the relationship that connects that slot to ``self.´´ This enables all the different varieties of cousins, 2^nd cousins, ½-cousins, and all the rest, to appear in their correct locations.

The family is rather unusual: both the father and the mother of ``self´´ remarried, so ``self´´ has stepsiblings and ½-siblings on both sides.

There´s a separate explanation of the notation.

Family Trees

Family

      Great-grandfather <= Great-grandmother
         Great-aunt => Great-uncle
         Grandfather <= Grandmother
            Aunt => Uncle
            Father
               <= Mother
               Brother <= Sister in law
                  Niece => Nephew in law
                     Great-niece => Great-nephew in law
                        Great-great-niece => Great-great-nephew in law
                        Great-great-nephew <= Great-great-niece in law
                     Great-nephew <= Great-niece in law
                        Great-great-niece => Great-great-nephew in law
                        Great-great-nephew <= Great-great-niece in law
                  Nephew <= Niece in law
                     Great-niece => Great-nephew in law
                     Great-nephew <= Great-niece in law
               Self ~ Ex-spouse
                  Daughter => Son in law
                     Granddaughter => Grandson in law
                        Great-granddaughter => Great-grandson in law
                        Great-grandson <= Great-granddaughter in law
                     Grandson <= Granddaughter in law
                        Great-granddaughter => Great-grandson in law
                        Great-grandson <= Great-granddaughter in law
                  Son <= Daughter in law
                     Granddaughter => Grandson in law
                     Grandson <= Granddaughter in law
                  ~ Spouse
                  Daughter => Son in law
                  Son <= Daughter in law
               Sister => Brother in law
                  Niece => Nephew in law
                  Nephew <= Niece in law
               <= Stepmother
               ½-brother <= ½-sister in law
                  ½-niece => ½-nephew in law
                     ½-great-niece => ½-great-nephew in law
                        ½-great-great-niece => ½-great-great-nephew in law
                        ½-great-great-nephew <= ½-great-great-niece in law
                     ½-great-nephew <= ½-great-niece in law
                        ½-great-great-niece => ½-great-great-nephew in law
                        ½-great-great-nephew <= ½-great-great-niece in law
                  ½-nephew <= ½-niece in law
                     ½-great-niece => ½-great-nephew in law
                     ½-great-nephew <= ½-great-niece in law
               ½-sister => ½-brother in law
                  ½-niece => ½-nephew in law
                  ½-nephew <= ½-niece in law
            Uncle <= Aunt
               Cousin
                  Cousin once removed
                     Cousin twice removed
                        Cousin 3 times removed
         Great-uncle <= Great-aunt
            Cousin once removed
               2nd cousin
                  2nd cousin once removed
                     2nd cousin twice removed
                        2nd cousin 3 times removed

Mother's family

      Great-grandfather <= Great-grandmother
         Great-aunt => Great-uncle
         Grandfather <= Grandmother
            Aunt => Uncle
            Mother => Father
               => Stepfather
               ½-brother <= ½-sister in law
               ½-sister => ½-brother in law
            Uncle <= Aunt
         Great-uncle <= Great-aunt

Stepfather's family

      Stepgreat-grandfather <= Stepgreat-grandmother
         Stepgreat-aunt => Stepgreat-uncle
         Stepgrandfather <= Stepgrandmother
            Stepaunt => Stepuncle
            Stepfather <= _____
               Stepbrother <= Stepsister in law
               Stepsister => Stepbrother in law
               <= Mother
               ½-brother <= ½-sister in law
               ½-sister => ½-brother in law
            Stepuncle <= Stepaunt
         Stepgreat-uncle <= Stepgreat-aunt

Stepmother's family

      Stepgreat-grandfather <= Stepgreat-grandmother
         Stepgreat-aunt => Stepgreat-uncle
         Stepgrandfather <= Stepgrandmother
            Stepaunt => Stepuncle
            Stepmother => _____
               Stepbrother <= Stepsister in law
               Stepsister => Stepbrother in law
               => Father
            Stepuncle <= Stepaunt
         Stepgreat-uncle <= Stepgreat-aunt

Grandmother's family

There are 2 copies of this, but they are identical. One refers to the paternal grandfather, the other to the maternal.

      Great-grandfather <= Great-grandmother
         Great-aunt => Great-uncle
         Grandmother => Grandfather
         Great-uncle <= Great-aunt

Spouse's family

      Great-grandfather in law <= Great-grandmother in law
         Great-aunt in law => Great-uncle in law
         Grandfather in law <= Grandmother in law
            Aunt in law => Uncle in law
            Father in law <= Mother in law
               Brother in law <= Sister in law
                  Niece => Nephew in law
                  Nephew <= Niece in law
               Sister in law => Brother in law
               Spouse ~ Self
            Uncle in law <= Aunt in law
               Cousin in law
                  Cousin once removed in law
                     Cousin twice removed in law
                        Cousin 3 times removed in law
         Great-uncle in law <= Great-aunt in law
            Cousin once removed in law
               2nd cousin in law
                  2nd cousin once removed in law
                     2nd cousin twice removed in law
                        2nd cousin 3 times removed in law

Spouse's mother's family

      Great-grandfather in law <= Great-grandmother in law
         Great-aunt in law => Great-uncle in law
         Grandfather in law <= Grandmother in law
            Aunt in law => Uncle in law
            Mother in law => Father in law
            Uncle in law <= Aunt in law
         Great-uncle in law <= Great-aunt in law

Spouse's grandmother's family

There are 2 identical copies of this too.

      Great-grandfather in law <= Great-grandmother in law
         Great-aunt in law => Great-uncle in law
         Grandmother in law => Grandfather in law
         Great-uncle in law <= Great-aunt in law

Ex-spouse's family

      Ex-great-grandfather in law <= Ex-great-grandmother in law
         Ex-great-aunt in law => Ex-great-uncle in law
         Ex-grandfather in law <= Ex-grandmother in law
            Ex-aunt in law => Ex-uncle in law
            Ex-father in law <= Ex-mother in law
               Ex-brother in law <= Ex-sister in law
                  Ex-niece => Ex-nephew in law
                  Ex-nephew <= Ex-niece in law
               Ex-sister in law => Ex-brother in law
               Ex-spouse ~ Self
            Ex-uncle in law <= Ex-aunt in law
               Ex-cousin in law
                  Ex-cousin once removed in law
                     Ex-cousin twice removed in law
                        Ex-cousin 3 times removed in law
         Ex-great-uncle in law <= Ex-great-aunt in law
            Ex-cousin once removed in law
               Ex-2nd cousin in law
                  Ex-2nd cousin once removed in law
                     Ex-2nd cousin twice removed in law
                        Ex-2nd cousin 3 times removed in law

Definitions

The above are derived from the following, where ``child´´, ``parent´´ and ``spouse´´ are the relationships defined (respectively) as

   {(a, c), (b, c)}
   {(c, a), (c, b)}
   {(a, b), (b, a)}

in

      a <= b
         c

aunt/uncle

parent´s sibling | parent´s sibling´s spouse

cousin

parent´s sibling´s child (shares 2 grandparents)

cousin once removed

cousin´s child | parent´s cousin

double cousin

father´s sibling´s child & mother´s sibling´s child (shares 4 grandparents)

grandchild

child´s child

grandparent

parent´s parent

½-cousin

parent´s ½-sibling´s child (shares 1 grandparent)

½-sibling

parent´s child \ sibling (shares 1 parent)

niece/nephew

sibling´s child | spouse´s siblings´s child

2nd cousin

parent´s cousin´s child (shares 2 great-grandparents)

sibling

father´s child & mother´s child (shares 2 parents)

stepchild

spouse´s child \ child

stepcousin

parent´s sibling´s stepchild | parent´s stepsibling´s child | parent´s stepsibling´s stepchild | stepparent´s sibling´s child | stepparent´s sibling´s stepchild | stepparent´s stepsibling´s child | stepparent´s stepsibling´s stepchild

stepparent

parent´s spouse \ parent

stepsibling

stepparent´s child \ parent´s child

(Someone who shares 3 grandparents with you is your ½-sibling and cousin simultaneously; is there a name for that?)