Slashdot Mirror
Humans Choose Friends With Similar DNA
KentuckyFC writes "The study of social networks has long shown that people tend to pick friends who are similar to them — birds of a feather stick together (PDF). Now a study of the genomes of almost 2000 Americans has found that those who are friends also share remarkable genetic similarities. 'Pairs of friends are, on average, as genetically similar to one another as fourth cousins,' the study concludes. By contrast, strangers share few genetic similarities. The result seems to confirm a 30-year-old theory that a person's genes causes them to seek out circumstances that are compatible with their phenotype. If that's the case, then people with similar genes should end up in similar environments and so be more likely to become friends."
How dare you insult my friends by comparing them to me!
No kidding. I'm thinking that the majority of people live, breed and die within a few hundred miles of where they were born and this goes on generation after generation. One would expect a certain homogeneity in the range of genes within that population.
Was there a control for geographically similar area? If you live in certain areas like Appalachia, everyone you know is probably a fourth cousin. So of course your friends would be related to you.
This is why I don't have friends - I'm not human.
Don't trust any concentration of power.
I find this study to be extremely flawed, not to say elitist / racist.
Yes, rednecks who listen to country music and drink cheap beer and whisky like to have friends who are also rednecks who listen to country music and drink cheap beer and whisky.
If the study had been conducted with 2000 subjects from culturally diverse places, like NY or Tokyo, I'm sure the results would've been a lot diferent.
I was going to post AC, but fuck it, I got karma to burn...
In a number of different memoirs from actors in the original Planet of the Apes, it was noted that people playing different types of apes always sat with each other at lunch. It was a bizarre granfalloon - baboons with baboons and orangs with orangs for no other reason than that they looked the same. And these were people that knew each other before the film.
People have a natural inclination to like people that look more like them whether it makes sense in modern society or not.
This is why I don't have friends - I'm not human.
What are you doing out?!? Get back in your cage!
A feeling of having made the same mistake before: Deja Foobar
After all, many friends fuck their friends' wives, so after a couple of generations, they are all a happy family.
There are often trade offs in adaptations. Sickle cell animia isn't great, but having part of those genes wards off malaria. More vulnerable to disease, but having people who are like us around might lead to more social benefit. Like if a father dies, another man might take over if the children are similar to him.
Well.. maybe. Or Maybe not. But Definitely not sort of.
If there are only six degrees of separation between you and just about everybody on earth, the classification "fourth cousin" probably covers a large part of the earth's population!
Slashdot just ran a story on universal genome sequencing at birth. How long before your prom date is set up before you're home from the maternity ward.
I'm reminded of the Better Off Ted episode Get Happy
Linda suggests that Veridian let its employees have decorations in their company. Veronica agrees, but the company selects the decorations and assigns them to the employees. Linda discovers that she's suddenly a cat person, while other employees have cars, Green Bay Packers, or space decorations.
"Veridian Dynamics. Teamwork. It keeps our employees gruntled."
It must have been something you assimilated. . . .
... white people are racist
how dare you say white people are racist!
Indeed! This is quite possibly, without exaggeration, the single most cruel and inhumane thing you can do to another person. Accusing another person of racism is so low that, I daresay, it ought to be considered a hate crime! I know I certainly won't stand for being accused of racism. I am a white human being with dignity, and I deserve better than that!
> So we evolved a tendency to monoculture, making us more vulnerable to disease? ... counterintuitive.
> That would seem
Not really, only if taken out of context and to the extreme. The relation between friends is states as about the same as a "fourth cousin". A fair amount of mixing happens even amongst the children of a single pair of parents with 2 copies of up to 4 possibilites being selected for each gene in each individual... fourth cousins is still enough room for quite a bit of diversity.
Think of it like plant or animal breeding. Breeders generally don't take two dissimilar phenotypes breed them once, and then take their progeny and look to whole new lines. They call those the F1 and then breed them back with another of their own type.
Is it really so surprizing that nature would have found the same trick for keeping some stability in the local gene pool? I mean, its hardly a case of "monoculture".
"I opened my eyes, and everything went dark again"
Nothing to see here, move along.
I'm sure that a few will claim "no, you are just anti-science" or some such but lets check a simple fact. 2000 genes were used in this study. What percentage of the human genome is this? Not only would this mean that "correlation == causation", but that correlation of 8.024e-6 (yes, that is a very small number) is the "normal".
-The wise argue that there are few absolutes, the fool argues that there are no probabilities.
Almost all of the participants in the dataset were Americans of European descent. They controlled for the possibility of distant relatedness as aggressively as they could, which is a well-understood requirement of many GWAS experiments.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
They did study a relatively cosy community, which was predominantly white. They removed as many families and evidence of distantly-related friends as they could using the Manichaikul et al. 2010 kinship metric, which has been cited 34 times (a fairly good number of hits for a two-year interval.)
The upshot of this study, in my opinion, is that the things that make people compatible friends happen to be reflected (to a degree) in certain markers in the genome. It doesn't necessarily indicate anything about race or relatedness, and you can probably predict that two people of radically different ethnicities may like each other as friends because of similarity simply due to the subset of markers that are important. It's a bit misleading of the authors to imply that this is somehow a pan-genome phenomenon when obviously there are plenty of things in the genome that could change without any detectable impact.
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
I've lived around the world and have a variety of friends.
Well neat. You alone must be a representative sample set of humanity that dwarfs this mere 1932 person sample group for statistical relevance. Thank goodness you know more about statistics than people doing a population study!
I'm assuming these 2000 individuals for the study were in environments that just happened to have similar genes around them.
Actually, if you read the study (OMG! I must be new here!), then you'll see that they address this point:
"There are (at least) four possible reasons that friends may exhibit homophily in their genotypes. First, correlation in genotypes may be a trivial by-product of the tendency of people to make friends with geographically proximate or ethnoracially similar individuals who also tend to share the same ancestry. Thus, it is important to use strict controls for population stratification in tests of genetic correlation (below, we rely on the widely used principal components method to control for ancestry). [...] Third, people may actively choose particular environments, and, in those environments, they may be more likely to encounter people with similar phenotypes influenced by specific genotypes. If people then choose friends from within these environments (even at random), it would tend to generate correlated genotypes."
[...]
"To eliminate the possibility that the results are influenced by people tending to make friends with distant relatives, we use only the 907 friend pairs where kinship â 0 (recall that kinship can be less than zero when unrelated individuals tend to have negatively correlated genotypes)." (ed: They do the same with 907 stranger pairs.)
In the end, they find that people prefer friends that share genes for the same sense of smell and the same linoleic acid metabolism. We also strongly prefer people with different genotypes for immune system function. While there are hundreds more homophilic and heterophilic gene correlations, those were the three that were most over-represented between people. There are many other genes that friends share, but most of those vary from pair to pair of people and are either idiosyncratic preferences or possibly just coincidences. Those three genes are not.
It's pretty well known that human select their lovers in part by smell. It's interesting that we pick our friends too that way. The paper gives a few good theories for why that's true (based on older research) and also does so for the immune system. The linoleic acid thing seems to have baffled them a bit, though they make a stab at explaining it as possibly being related to food safety and keeping the community on the same page about what's good to eat.
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
But since race is only about 1% of DNA, you could be like them in many other ways.
Peter predicted that you would "deliberately forget" creation 2000 years ago...
It sounds to me like they shot an arrow into the side of a barn, then drew a bulls-eye around it, afterwards.
"Flyin' in just a sweet place,
Never been known to fail..."
"Hey babe, is this guy boring you? I'm from another planet!"
"Flyin' in just a sweet place,
Never been known to fail..."
I dont get how everyone on here keeps making the equation: genetics = race. Thats not what this is about.
I'm an engineer. Since I was a kid, I've loved to take things apart and put them back together. The closest friends I have in life are all from different parts of the world but they tend to be like me in that they also grew up taking things apart and putting them back together. So whatever gene-grouping is responsible for that behavior is probably shared by my friends from India, Russia and Sweden.
Genetics != race
This study fails on two counts: Americans are statistical outliers; the conclusion is fallacious due to poor understanding of causality.
For those for whom this is TL;DR -- Americans are the worst possible population to base any form of human study on (let alone a flawed study) - ref Solomon Asch's conclusion. The short summary @ neuroecology ; the longer discussion @ pacific standard.
But try this little thought experiment: take some random Anyville, USA. How much have they travelled, how diverse is their population? How do populations move? How many are going to marry from the same town, as did their parents and grandparents, and how many are going to have children and grandchildren doing the same? And even if the population started out with diversity, you can lather, rinse, repeat the marriage/procreation suds and end up with a genetically similar pool of people - the town itself holds massively similar people on average.
Those of us who are more footloose and have moved around further are still statistical anomalies, insomuch as we often hail from outside of these wells of similarity. That is not to say that since we're so different, we cannot make friends with those whose families are long time residents, nor does it exclude the idea of having a multicultural community of extremely different people, DNA-wise.
But at its core, the fault of this study is basic: a textbook example of correlation-causation fallacy.
-- "Simplicity is prerequisite for reliability." --Dijkstra
The suspicion that part of social compatibility can be explained through superficial genetic traits has been explored before. The bibliography on page 21 of the totally free and unpaywalled arxiv PDF has a few citations that seem pretty similar.
That being said, I'm not so sure about some of their conclusions; they make it sound like there are purely mechanistic reasons why we seek out the friends we do. Consider the following:
The implications of the finding regarding homophily on genes related to linoleic acid metabolism are unclear. Linoleic acid is a precursor for substances involved in a broad range of important bodily processes (ranging from adipocyte function to bone formation to the regulation of gene expression) (42), and the component genes in the pathway are related to the metabolism of cholesterol, steroids, and various ingested substances, though it is intriguing that linoleic acid compounds might be used by moths as pheromones (43). Possibly, this pathway is related to the restrained consumption or the specific metabolism of various foodstuffs, traits for which homophily may be advantageous and heterophily self-injurious.
Personally, I think this is patently absurd and that there is no way this could influence personality or human behaviour. It seems to me to be more likely that the linoleic acid genes either have some wildly obscure indirect effect on personality that we can detect, or that they're simply inherited by chance with something that does.
It would have been wonderful if people here actually bothered to RTFA so we could argue about whether or not biochemically-inclined sociologists are out to destroy civilization by being too narrow-minded. On the plus side, this is a biology paper that was submitted to Arxiv, which means that it probably is having trouble getting into a major journal (i.e. it's very possibly being regarded as crap by journal editors due to its weird conclusions.)
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
All humans have "similar" DNA
Wow, what an amazingly useless statement. Hey, scientists! SlithyMagister has declared that there is no point in describing genomics at a more fine-grained level than the species level. Field's closed -- everyone out!
Of course, the issue is the matter of degree of similarity. They found that friends were more similar than strangers, to the point that they were as similar as fourth cousins. That would be fascinating on its own, but they also found that friends were specifically more similar in two ways -- sense of smell and linoleic acid metabolism -- and specifically different in immune system function.
If it's for-profit but free, you're not the customer -- you're the product (e.g., the Slashdot Beta's "audience").
This doesn't really work in today's world, though. Sure, in suburbs and villages, that probably has something to do with it. Cities, though? A city hash millions of people living in it, many of them not even originating from that city at all. Walk a hundred meters and you'll probably stumble on people from 10 different countries at the very least. I have serious doubts that you, by happenstance, always pick people who grew near your own place of birth.
That doesn't make the findings impossible. The genetic variation is known or could be estimated given the demographics of a person's locale, and you could compare the profile of expected (if friend making was completely random) to actual pretty easily. If they don't match up, then there's some selection going on.
For example, if you're white and live in the bronx, and significantly less than half of your local friends are hispanic, then obviously race factors into who you make friends with in some way. You could do the same thing with genetic markers.
What's so difficult to understand? You can't comprehend that some women like sex as much as men?
I've never met a woman who knows what a proper orgasm is who didn't love sex as well. plenty of women who haven't been properly pleasures don't like it, sure. Not ones who have had a good orgasm though.
Perhaps your view is skewed do to your own issues. And before you respond, just because you can jackhammer her for an hour, doesn't mean any part of it was good. 9 out of 10 women would rather have a good quickly than an hour that just makes them sore and disappointed.
Persistent Volume manager for Kubernetes - https://github.com/dwimsey/openshift-pvmanager
But there are mechanisms for learning; mechanisms we know must exist and, to some extent, even understand. The subtleties in them form the foundation of who we are when we are conceived, and interplay with our experiences as life continues. They are the tie-breakers that prevent us from being completely at the mercy of our situations, and what ties us to our parents even if we have not met them.
What these people do is claim there is nothing more, and it is obvious they have no knowledge of cognitive science (or possibly other people). That is self-evidently wrong. But there's nothing inhuman about being a machine if that machine can learn, grow, and discover the universe. Would you deny personhood to an artificial intelligence with the same potential?
Bio questions? Ask me to start a Q&A journal. Computer analogies available for most topics!
That doesn't disprove anything. This is about people in general, not about one person in particular, and it never said you will become friends with everyone close to you. You may be not be friends with 200 of your neighbors but at the same time you're not friends with 4 million people from China.
This is statistics too. No one said that this was true for every single human being. If someone says that more people voted for Obama than for Romney, stepping forward to say "that's not true, I voted for Romney!" is irrelevant.
And there many "white" Americans who've got some African ancestry and don't even know it.
Il n'y a pas de Planet B.