What friends' genes say about you
January 17th, 2011
04:59 PM ET

What friends' genes say about you

There's a lot of focus these days on tailoring treatments for diseases to individuals based on their genes, but friends' genes might be just as relevant, scientists argue.

It turns out that there are genetic correlations among people in the same social group, a new study in the journal Proceedings of the National Academy of Sciences finds.

"We’re not just a product of our own genes, but those of others around us," said study co-author James Fowler, associate professor at the University of California, San Diego. Fowler and Dr. Nicholas Christakis of Harvard, another study collaborator, previously penned a book called Connected detailing how everything from obesity to happiness to loneliness seems to spread in social networks.

The genetic links found in this new study go beyond the idea that you might be friends with your second cousins other distant relatives. Instead, this research shows that you may actually share predispositions toward certain behaviors with your friends, regardless of whether they share your ancestry.

Long before this relatively recent scientific inquiry into how members of social networks influence each other, organizations such as Alcoholics Anonymous and Weight Watchers were already taking advantage of those principles. In Alcoholics Anonymous, people susceptible to drinking come together with the purpose of quitting, and group members help each other in their determination to abstain from alcohol.

And to some extent, people are already sharing their genetic information, Fowler said. Some services allow users to post results of their genetic tests for friends and family to see.

Fowler and colleagues examined data from the National Longitudinal Study of Adolescent Health.  They found that people who have the genetic marker DRD2, associated with alcoholism, tend to befriend each other, and those who do not have this marker tend to associate with others who lack it.

On other other hand, they found a different relationship with a gene involved in the system that metabolizes foreign substances, such as nicotine.  It seems that people with this particular marker befriend people who don't have it. Fowler suggests that in terms of having social support, there might be some benefit in having close contacts who are better with dealing with toxicity in the environment than you are.

"It’s possible that part of the story is that our fitness as individuals depends not just on our own genes, but on the genes of other people," Fowler said.

It's true that people who drink a lot might naturally gravitate toward each other anyway at a bar, for example. But the result that opposites attract for the other marker may reveal a deeper connection: You also choose friends who would not necessarily find themselves in the same venues that you would, indicating that there could be something going on at the genetic level, too, Fowler said.

soundoff (76 Responses)
  1. Joe

    I'm totally attracted to bar hopping, alcoholic, pill popping bimbo floozies. Not sure what that says about my genes though.

    January 17, 2011 at 17:46 | Report abuse | Reply
    • Ruby

      Well Joe, it means either that you are like them, or that you are not. Isn't science great?

      January 17, 2011 at 21:25 | Report abuse |
    • kate

      Maybe it just means they are friendlier. : )

      January 17, 2011 at 22:00 | Report abuse |
    • biscuits and gravy

      I think it says your genes are likely wide-spread in those bar-hopping, alcoholic, pill-popping floozies

      January 17, 2011 at 22:16 | Report abuse |
    • biodan

      Your genes recognize the easy mark! Make many babies.

      January 18, 2011 at 01:03 | Report abuse |
    • EM

      ... but are you attracted to what's in their JEANS ? .........

      January 18, 2011 at 01:09 | Report abuse |
    • justincase

      I am normally not attracted to pill popping, alcoholic, bar hoping floozies but I could use one now.

      January 18, 2011 at 09:24 | Report abuse |
    • Hilary

      We should go out sometime. You sound cool.

      January 18, 2011 at 15:15 | Report abuse |
    • Donna

      biscuits and gravy wins the thread!

      January 18, 2011 at 15:24 | Report abuse |
  2. Mike

    Let me get this straight.

    Alcoholics tend to hang out with alcoholics?

    I'm glad I took that genetics course or I'd be so confused.

    January 17, 2011 at 17:54 | Report abuse | Reply
    • Noocrat

      Thanks for a cherry picking a single line without acknowledging its counterpoint. It really contributed a lot.

      January 18, 2011 at 09:06 | Report abuse |
  3. sora

    Opposites attract at times, and similar people are attracted to each other at times... And often for reasons of benefit. Wow. Where would we be without these academics enlightening us with their insights?!

    January 17, 2011 at 19:45 | Report abuse | Reply
    • justincase

      If we don't have people asking questions and making supositions based on studies we would remain totally full of ourselves and confortable that we already know everything and don't need to know more than what is in the Bible. My point here is ask questions, do studies, create insights, it is called human behavior. If you want to ignore that part of yourself then just be another moronic Bible, Koran, Torah reading simpleton.

      January 18, 2011 at 09:16 | Report abuse |
    • Duh

      Do you even know how many "insights" are not true? Let me just give you one: world is flat.

      January 18, 2011 at 11:22 | Report abuse |
  4. bspurloc

    so if u met all your friends from online gaming then its a good guess that u are all depressed losers

    January 17, 2011 at 19:55 | Report abuse | Reply
  5. Moodyme

    I don't "gravitate" toward any of my large family because I don't particularly like any of them. Yet they share my DNA.

    January 17, 2011 at 20:08 | Report abuse | Reply
    • justincase

      Don't feel bad I don't like your family either!

      January 18, 2011 at 09:16 | Report abuse |
    • Jen

      Maybe you're actually adopted.

      January 18, 2011 at 09:19 | Report abuse |
    • Duh

      Maybe the genes your family have are the kinds that hate one another in the family.

      January 18, 2011 at 11:19 | Report abuse |
  6. mk

    this is the dumbest 'scientific' article i ever read

    January 17, 2011 at 20:15 | Report abuse | Reply
    • Jeff S

      With a statement like that you must have a wealth of knowledge after reading all the scientific articles.

      January 18, 2011 at 01:44 | Report abuse |
    • Joel

      There may some actually science behind the findings, but the writer of the article sure doesn't seem to understand the science. Not well written.

      January 18, 2011 at 04:43 | Report abuse |
  7. Pamma

    Birds of a feather, flock together

    January 17, 2011 at 22:17 | Report abuse | Reply
  8. Steve

    Huh, people who have fewer common traits (and therefore are not likely to live in the same place) tend to live in the different places, run in the different circles and not socialize. Who knew?

    January 17, 2011 at 22:57 | Report abuse | Reply
    • Wzrd1

      Yeah, because the United States is ALL one race and ethnic group, right?

      January 18, 2011 at 00:00 | Report abuse |
  9. Jim

    Actually, it makes sense. People call their dogs best friends, that's because dogs are different from humans. Opposites attract.

    January 17, 2011 at 23:07 | Report abuse | Reply
  10. EM

    I like gals with big boobs ... is that genetic?

    January 18, 2011 at 01:10 | Report abuse | Reply
    • B C

      I knew I had a family member out there that I had yet to meet.

      January 18, 2011 at 02:13 | Report abuse |
    • EM


      January 18, 2011 at 11:12 | Report abuse |
    • Duh

      Yeah, I notice those genes are usually tight-coupled with the small pen!s genes.

      January 18, 2011 at 11:25 | Report abuse |
    • shegirl

      Yeah, it is genetic: the Y chromozone. Your a guy, they like big boobs. Good luck with that, I'm sure you will find a meaningful relationship with criteria like that.

      January 19, 2011 at 00:08 | Report abuse |
  11. Jose

    What a bunch of crap.

    January 18, 2011 at 01:14 | Report abuse | Reply
  12. Bronson

    Things are relative to one another? Imagine that! My, what an amazing world we live in! I need a scientist to tell me I may share similar character traits with people I hang out with? Has science simply become science of the obvious or what?

    January 18, 2011 at 01:30 | Report abuse | Reply
    • justincase

      Actually it is my opinion that you do not understand the gravity of what the study is proposing. I do agree the article is written poorly and could lead to misunderstanding. The study is showing there is MORE than genetics at work here, that behaviors, genetics and human symbiology interplay together in a complex web of need, comfort and attraction.

      January 18, 2011 at 09:20 | Report abuse |
    • EM

      : Agreed. I recall decades ago in my Boreal Ecology class studying something called "filter-bridging". The theory that animals migrated through corridors from one area to another, and that the corridors 'filtered' out those who were less risk-averse to stay behind, whilst animals willing to take higher risks moved on through corridors (which contained risks such as predators) towards the potential rewards of better areas. The added risk, of course, is that the destination areas were, in fact, less productive (i.e., food-wise), than what they left behind! But it was a total risk-package, and those most willing to take the total risk, tended to, in the end, benefit.

      I believe that can apply to human behavior too, where we 'move' in life towards 'areas' of new associations with new people. There is a risk involve, but we do so looking for potential rewards - friendships, love, money, you name it. However, depending upon one's personality (our genes?) some of us are more risk-averse, so avoid certain 'areas', whilst others go there. Again, the ones with the highest risk tolerance net-out the benefits in the end, but of course there would be a lot of failures too along the way. Kind of like running a business ...

      Fascinating theories, don't you agree?

      January 18, 2011 at 11:23 | Report abuse |
    • Duh

      Character traits may also have been caused by environmental upbringing. Imagine that.

      January 18, 2011 at 11:23 | Report abuse |
    • EM

      oops, i forgot to mention that it was @justincase with whom I was agreeing

      January 18, 2011 at 11:24 | Report abuse |
  13. superjadakay

    This is like the worst article ever...Total FAIL

    January 18, 2011 at 01:35 | Report abuse | Reply
  14. Mike

    Why did CNN allow this crap to be posted?

    January 18, 2011 at 01:37 | Report abuse | Reply
    • Jeff S

      Probably because it had a high chance of generating page views thus increasing the ad revenue. Its not rocket science genius.

      January 18, 2011 at 01:46 | Report abuse |
    • justincase

      Because Mike if you were to publish a paper it would be dedicated to bikini bimbo's carrying a weapon in one hand and a baby in the other and your follow up story would be angry over weight middle aged white men screaming take back our country.

      January 18, 2011 at 09:22 | Report abuse |
    • Bill

      You do know what the "C" in "CNN" stands for, right, Mike? 😉

      January 18, 2011 at 13:40 | Report abuse |
    • Lenin

      T! And remember, in December, the Cooperstown thing 🙂 Good lord, Janet sold aomslt all my stuff. I love Coop. I will need to return sometime soon, can I try to say hello to you again?

      March 4, 2012 at 08:37 | Report abuse |
  15. Edward

    Opposites don't really attract, we naturally gravitate towards people that have the same interests as us.

    January 18, 2011 at 01:52 | Report abuse | Reply
  16. bob

    This is garbage!!!

    January 18, 2011 at 01:58 | Report abuse | Reply
  17. Yoda

    In AA and weight watchers desperate people come together an form absurd cults based around pseudoscientific ideas and group think, achieving next to nothing while filling the massive void in their lives. There, I fixed the article for you!

    January 18, 2011 at 02:48 | Report abuse | Reply
  18. Lauism

    Another stupid article that states the obvious, sugar coated in the name of "science" and research.

    January 18, 2011 at 04:14 | Report abuse | Reply
  19. Dick

    So , you come 'round here often? Can I buy ya a drink?

    January 18, 2011 at 04:47 | Report abuse | Reply
  20. jessicajone18

    I use "123 Get Samples" to find free samples of major brands online. Please note they update their samples every day but I just pick what ever available at that time and use them.

    January 18, 2011 at 04:53 | Report abuse | Reply
  21. khanssen

    How silly. As somebody who has smoked AND spent way too much time in bars, it's pretty obvious that you find a friend set with the same interests. The friends from college I kept the longest were those who would go out drinking with me, and a lot of my newer friends are those who would go out for a smoke with me while at said bars.

    January 18, 2011 at 05:22 | Report abuse | Reply
  22. Terry - Indiana

    So, if my dog stops to pee on a tree, there is suggested research proof that I too will pee on the tree. Sorry officer, my dog made me do it!

    January 18, 2011 at 06:10 | Report abuse | Reply
    • courtside

      You were peeing on trees long before you even got that dog, He learned it from you!

      January 18, 2011 at 10:30 | Report abuse |
  23. Kyle

    Everyone in here is a butt-hurt @hole who probably thinks science is only legit when they don't understand it. I'm guessing the average person reading this graduated with a PhD in Behavioral Genetics? Not science just an assumption cause we have a lot of experts on our hands... You complain about the simplicity, yet you're reading this article and not a science journals website with comparable findings. Freakin' bunch of amateurs.

    January 18, 2011 at 08:42 | Report abuse | Reply
  24. Ella McGillicuddy

    Why the new buzz...? Were we not always influenced in a positive or negative way by people we chum with??? Isn't that what are parents teach us growing up???

    January 18, 2011 at 08:54 | Report abuse | Reply
    • Ella McGillicuddy

      excuse me.."our" parents teach us

      January 18, 2011 at 08:55 | Report abuse |
  25. Holy Moses

    Another goober study.

    January 18, 2011 at 09:01 | Report abuse | Reply
  26. fishies

    Man, I am glad the vast majority of the comments here shows we're not all as simple as this article. 🙂

    January 18, 2011 at 09:06 | Report abuse | Reply
  27. Tim

    Friends have things in common? Since when?

    January 18, 2011 at 09:06 | Report abuse | Reply
  28. Roflmoa

    I blame obama.

    January 18, 2011 at 09:23 | Report abuse | Reply
    • Duh

      For getting his dad's Harvard-Law-proficient genes?

      January 18, 2011 at 11:29 | Report abuse |
  29. Theotormon

    The results of this might seem obvious, but that doesn't make the science foolish. Scientific studies frequently overturn conventional wisdom. Also they frequently validate it. It is good to look at things objectively and see which things we all believe actually hold up under investigation. For example, a lot of people would find it obvious that there are specific genes determining a person's race or that emergency rooms are busier on full moons, but both of these beliefs have been disproven by science.

    January 18, 2011 at 09:30 | Report abuse | Reply
  30. Princess S

    I think this study just elaborates on what we already know: "Birds of a feather flock together".

    January 18, 2011 at 09:47 | Report abuse | Reply
  31. Izzy Roush

    Speaking of Genes..

    From Dr.Bryan Ness and his students; Department of Biology, Pacific Union College, Angwin, CA 94508.

    What do you get when you cross a potato with a sponge?
    I don't know, but it sure holds a lot of gravy.

    What do you get when you cross a gorilla with a computer?
    A hairy reasoner. (Maybe too old for today's students.)

    What do you get when you cross a parrot with a lion?
    I don't know, but when it speaks you better listen.

    Where would one find genes retired from the human genetic pool?
    In an old folks genome.

    Cell about to undergo mitosis to an interested geneticist: "I hope I have your divided attention"

    What do you get when you cross a bridge with a bicycle?
    The other side.

    What do you call a 6-legged insect that can't speak? A mutant.

    Q: How do you tell the difference between a male chromosome and a female chromosome?
    A: Take down their genes (jeans)!

    What do you call a Drosophila who likes to drink? A bar fly.

    January 18, 2011 at 09:55 | Report abuse | Reply
  32. Izzy Roush

    Speaking of genes...

    Man goes to the doctor
    Can you help me, I have a hereditary disease?
    What disease is that?
    That’s not a hereditary disease!
    It is when it’s in your genes.

    January 18, 2011 at 10:02 | Report abuse | Reply
  33. courtside

    So we all must have some similarities by coming onto this website, looking at this article and feeling the need to make a post

    January 18, 2011 at 10:33 | Report abuse | Reply
    • Kyle

      best post i've read. teh internets do make our 'circle' a little bit wider, our influences aren't just the kids we waited for the bus with; the internet has it's own culture that is concurrent with local culture, and at the end of the day it's all G x E = you.

      January 18, 2011 at 10:54 | Report abuse |
  34. Kyle

    Be glad to, but you'll have to get your head out of it first.. Should I wait for your views now or come back in May when your done freshman psych?

    January 18, 2011 at 11:18 | Report abuse | Reply
  35. LIP

    I think I will take this opportunity to say "nothing" and see if I attract someone else feeling the need to say "nothing". Perhaps we can become acquanited and say "nothing" to each other and maybe there will be others that will gravitate to our group saying "nothing" and soon we will lead a national movement called "the nothing" movement and we will soon dominate the world and.......

    January 18, 2011 at 11:32 | Report abuse | Reply
  36. Steve

    Researchers are a bunch of over paid hacks,telling everyone crap until they can retire.They always say we've made progress but more research is needed.In other words,give us more money.

    January 18, 2011 at 17:03 | Report abuse | Reply
  37. Andrew

    I don't really see the science behind this, other than identifying the genes. I think it's a subconscious decision that we make. Those who drink, like myself, will gravitate to those who drink because it's a social activity with the feel good factor reward. Those who smoke, although they may enjoy the immediate relief it gives them, are more conscious of the negative effects smoking has on the body and therefor (subconsciously) seek the company of those who do not smoke – to act as an aid in limiting the habit. More so is that as a non-smoker, I feel (in a high-horse self-righteous kinda way) that I should try to help smokers quit and as such find myself in situations where that might be possible.
    In order for such a generic theory to be accurately examined, the study would have to be taken from an eclectic demographic... I'd be interested in the results.

    January 19, 2011 at 13:16 | Report abuse | Reply
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    January 21, 2011 at 04:41 | Report abuse | Reply
  39. olmon

    Like that is something new ? ? ? The saying 'Birds of a feather' Was in use many generations ago. How much $$$ was wasted on this project ? ? ?

    January 23, 2011 at 08:08 | Report abuse | Reply
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