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Friends are as genetically similar as fourth cousins

pnas.org

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Re: Friends are as genetically similar as fourth cousins

#2

Post by douche »

Where I grew up, it's a pretty good chance all my friends were fourth or fifth cousins. Small population + limited outbreeding = family hedges, instead of family trees.

There were kids in my grade who couldn't date in town because all the girls were their first or second cousins...

Re: Friends are as genetically similar as fourth cousins

#3

Post by roninb »

In case you were also wondering what a "fourth cousin" was, someone who shares a pair of great-great-great grandparents[0]. Wikipedia has a great set of diagrams[1] in case you're also confused about first, second, or third cousins. I figure through induction you can presume any nth and nth removed from that page (I foolishly thought 3rd was where people arbitrarily stopped keeping count....)

[0] https://www.reference.com/family/fourth-cousin-7b40e096c6d65...

[1] https://en.wikipedia.org/wiki/Cousin#First_cousins

Re: Friends are as genetically similar as fourth cousins

#4

Post by ilaksh »

Could it just be more common for people who are in the same social group to be in the same ethnic group, and maybe that explains most of the genetic similarity they saw, rather than necessarily proving some kind of fitness advantage or something? Probably because often your friends are from the same neighborhood.

Re: Friends are as genetically similar as fourth cousins

#8

Post by astazangasta »

This is a dataset designed to study genetics in a cohort of mostly white people from Framingham, MA. How can anyone claim to be able to draw conclusions about the genetics of friendship from this cohort? This is such a biased dataset I can't believe this got published.

For the record, I am Indian, my best friend growing up was Italian, my current best friends are a Russian Jew, a Scotch Irish mix from Woburn, and a Canadian of some uncertain European temperament. I have never had a best friend even close to being my fourth cousin.

Re: Friends are as genetically similar as fourth cousins

#9

Post by skylan_q »

roninb wrote: post #3

In case you were also wondering what a "fourth cousin" was, someone who shares a pair of great-great-great grandparents[0]. Wikipedia has a great set of diagrams[1] in case you're also confused about first, second, or third cousins. I figure through induction you can presume any nth and nth removed from that page (I foolishly thought 3rd was where people arbitrarily stopped keeping count....) [0] https://www.referenc…

Where our family is from the priests wouldn't allow marriage between 6th cousins. My grandfather was 6th cousins three times removed from my grandmother. (so she was 9 generations away from common ancestors with him) They had to get written permission from the bishop to get married.
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