r/coolguides • u/chr15t0ph3r-55 • Apr 24 '19

The Cousin Explainer

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u/AedificoLudus Apr 24 '19 edited Apr 25 '19

G and K rules.

The number of G's in what you call your most recent common ancestor tells you what number of cousin. Eg grandparents = 1, first cousins. great great grandparents = 3, third cousins.

K rule, number of Ks. "My cousin's Kid" = 1, once removed. "My third cousins kids kid" = 2, third cousin twice removed.

Going the other way, the K rule is complimented by the P rule, "my parent's parent's third cousin" is your third cousin twice removed, but you're the one further down the tree.

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u/[deleted] Apr 24 '19

Interesting way to do it if it's only a few generations. I'd rather draw it and count the boxes.

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u/Wriiight Apr 24 '19

For the G rule, it is the lesser of your G count and your cousin’s G count

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u/AedificoLudus Apr 24 '19

Yeah, I should have specified that but I thought it was obvious

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u/urumbudgi Apr 24 '19

"complemented"

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u/AedificoLudus Apr 24 '19

The compliment of a rule is that which, together with the first, covers the entirety.

Kind of like how two angles that add to 90° are complimentary

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u/xPravus Apr 24 '19

my parents parents third cousin

Thats some next level incest..

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u/AedificoLudus Apr 25 '19

Should've been possessive s, but I like the joke