This is interesting as I've typically made friends along lines of interest. I guess my next question would be are genetically similar people more likely to have similar interests.<p>edit: corrected grammer
> The tendency for friends to have similar genomes might result from people befriending those of similar ancestry, but the duo are confident that isn't the case. Not only did they control for the effect of population structure and ancestry, but the Framingham data is relatively homogeneous in terms of ethnicity, consisting largely of people of European descent.<p>How did they control it? Even amongst Europeans, I imagine French people are just more likely to have French friends.
I have anecdotally noticed this with tall people and short people, I will notice a group of friends who are all 6'2"+, or who are all <=5'7", both of which seem statistically unlikely. There are plenty of more diverse groups (in terms of height) but its hard to say whether they are work friends or something else where you have less overall choice.
<i>"The opposite pattern held for genes related to immunity -- friends tended to be less similar at those parts of the genome."</i><p>It would have been more accurate to title this article "Friends Are Genetically Similar in Some Ways and Different in Others" but I guess that would not have been as edgy.<p>EDIT: The overall trend reported is that friends are more genetically similar than would be expected, as pointed out by user <i>Real_S</i>. Good title, after all.
The study mentions the 1% similarity, which is the genetic equivalent of fourth cousins. That's fine, but isn't there a heavy correlation between DNA origin and geography, and another correlation between friendship and geography??
There was a book I read in the 1970's about "sociobiology" that explained this. If I remember right:<p>People share exactly 50% of their genes with their parents and children, but only <i>probably</i> 50% of genes with siblings -- it could be 51%, or could be 48%. To preserve their own genes, people will feel altruistic to give their lives for three of their siblings (about 150% of their own genes saved), but not for one sibling (only about 50% saved). People share between 90% to 110% of their genes with two siblings (I'm guessing the variance here), so will give their lives for two siblings they share 110% of their genes with, but not two they only share 90% with. The feeling of "liking a sibling as a friend" is the same as being willing to give one's live for them, so in today's age of large urban groups where friendship is a proxy for one's siblings in small tribes during the hunter-gatherer era, it follows people choose their friends <i>because</i> they share more than the average genetic material with them.
> Topping the list for common genes were those related to our sense of smell. One explanation for this is that people with similar olfactory genes will smell things in the same way and so be drawn to (or repulsed by) similar environments... The opposite pattern held for genes related to immunity -- friends tended to be less similar at those parts of the genome.<p>This makes me think of the thesis of "Sex At Dawn" by Christopher Ryan and Cacilda Jetha. If humans evolved as polyamorous foragers for whom communal bonds were more important than paternal certainty, then it makes sense that you want your friends to like the same environments and add immunological diversity to your shared gene pool.
The same is true of spouses, and in fact, the healthiest couples (or at least those with the most children) seem to be third or fourth cousins:<p>"Third Cousins Have Greatest Number Of Offspring, Data From Iceland Shows"<p><a href="https://www.sciencedaily.com/releases/2008/02/080207140855.htm" rel="nofollow">https://www.sciencedaily.com/releases/2008/02/080207140855.h...</a><p>Not exactly what you'd expect given how often we see "hybrid vigor" touted as a purported benefit of interracial marriage.
Basing this on the Framingham study doesn’t say much. We do know homophily is very common world-wide, but Boston in particular is extremely segregated. Out in the burbs it’ll be largely small pools of ethnic (European) groups. While the summary at least touches on this, it would totally flop in diverse areas like SF or NYC. Most of my friends are from all around the world — if they all still shared some genes in a way that was uncommon I’d be extremely surprised.
Reminds me of this: <a href="http://www.neatorama.com/2013/12/15/When-the-Actors-in-Planet-of-the-Apes-Donned-Their-Makeup-They-Spontaneously--Segregated-Themselves/" rel="nofollow">http://www.neatorama.com/2013/12/15/When-the-Actors-in-Plane...</a><p>Humans are still amazingly tribal creatures.
Anyone know if the genetic similarities that we become friends around according to the study aren't related to race? To me that would be the most interesting part (if it wasn't).<p>I am pretty sceptic about this study and it seems kind of filled with opportunity for interpretation and bias plus have no idea of the data set.
This seems to make the kin selection vs. group selection controversy even more trivial: <a href="https://blog.oup.com/2015/01/kin-group-selection-controversy/" rel="nofollow">https://blog.oup.com/2015/01/kin-group-selection-controversy...</a>
Hmmm... As someone of sub-continental heritage, I have close friends from about 3 different ethnic groups. I have NO friends from my own cultural/regional heritage at all in 5 decades of walking this planet.
Study summary in one picture :)<p><a href="https://iwsmt-content-ok2nbdvvyp8jbrhdp.stackpathdns.com/52520132332151.jpg" rel="nofollow">https://iwsmt-content-ok2nbdvvyp8jbrhdp.stackpathdns.com/525...</a>
Does this mean that if you have similar experiences, then your genes change? I have found that experiencing things together forms friendships much more than genes.
Is it anymore likely that people with 1% genetic similarity have that connection randomly than the possibility they in fact share g-g-great-grandparents? i.e. 2 slots in the 32 level of their family tree, or what if they are double fifth cousins, sharing four slots at the 64 level?(is that math correct?)<p>So in effect for these similarities to present, they have to be cousins on some level right? Whether that is sharing N slots at the 2048 level, or some other combination?<p>In a sense all of humanity are cousins, and races are clusters with a higher coefficient of cousin-ness than the global average.
i found out recently that my lifelong best friend and i share a relatively uncommon paternal haplogroup, despite our families coming respectively from germany and scotland for the most part (the group is relatively prominent in frisia). anecdote, not data obviously, but i'm curious if anyone else has any similar experiences.
friends are economically similar and how much money you make relative to the rest of the society depends almost entirely on how much money your parents made relative to the society.
Wealth passes alongs genetic lines so does friendship.
Having read "The Selfish Gene" I wasn't surprised.
This study conclusion fits pretty well within the general theme of the book.<p>If you haven't read it yet, I highly recommend it!
People need to realize we are built on hardware that is hundreds of millions of years old. We share a similar hormonal dominance hierarchy system with fucking lobsters. You can't just say it's </CURRENT YEAR> and expect these things to disappear. Tribalism was important for survival, trusting someone who didn't look like you could mean death and thus was selected for over long periods of time.