The benefits of xenophobia

Xenophobia is neither the fear of Xeni, nor of Xena. Rather, it's more about knee-jerk mistrust, dislike, and hatred for people who aren't part of your group. We've come to associate it with not liking people from other countries, but it applies to smaller-scale, less formal tribalism, as well.

Over at the Scientific American blogs, science writer and biologist Rob Dunn talks about some of the theories for why something as seemingly antisocial as xenophobia could have been beneficial to our ancestors—at least under certain circumstances. The key, he says, might be disease. Not cooperating between groups, refusing to share resources, and generally going out of your way to avoid strangers makes sense if those strangers are infected with something that could kill you.

If I'm understanding Dunn correctly, the research and theorizing on this topic isn't saying xenophobia is good. Nor is it saying that all xenophobia grows out of a conscious, reasonable fear of disease. It's more like, the times when xenophobia did turn out to be coincidentally beneficial happened to reward people who were more likely to pass on xenophobic tendencies to their offspring (whether those tendencies were genetic or cultural is hard to say). Thus, the tendency continues, even in situations where it's actively detrimental. And Dunn points to an interesting recent study that showed deadly white-nose syndrome is causing xenophobic-esque changes in the behavior of bat populations.

Although it looked as though the little brown bats and several other species might soon face extinction, at least in some regions and perhaps even in North America, the little brown bats have begun to rebound in some places, albeit modestly. A new paper out this week takes notice of one of the reasons they appear to be rebounding, the bats are avoiding each other. Little brown bats (at least historically) tend to roost in large, groups, one next to the other, bumping fuzzies as it were. But not anymore. More and more, this new study, led by Kate Langwig, a graduate student at Boston University, suggests, the bats are spreading themselves out in their roosting caves, their hibernacula. Once, they clumped, warming themselves around the tiny fires of their bodies. Now, they go it alone.

Langwig’s results are preliminary, as she and her colleagues are the first to admit. She has measured the change in the bat roosting (and abundance) before and after the arrival of the disease, but she has not really studied the behavior of the bats and how it is they come to be spaced apart. Yet, the bats the are important from the perspective of the basic biology and conservation of the bats and so there remains much to do and much that can be done. For example, it would be good to know if the probability of transmission of the disease really goes down when the bats are further apart. It would also be interesting to figure out if the same individuals that were once nuzzling up next to each other, are now hanging out on their own.

Read the rest of Rob Dunn's post on xenophobia and disease

Via Discover's 80 Beats blog



  1. Are you sure it isn’t the fear of never getting to your destination because you only travel half of the remaining distance at a time?

    1. This is offtopic, but…

      You can’t say ‘never’. You divorced the concept of speed from the paradox. You travel half the distance in half the time, then another quarter the distance in a quarter the time, etc. ‘Never’ implies a time greater than the distance divided by the speed.

      If you somehow decided to cut your speed in half after each half-splitting distance traveled, then you will never make it.

      1. The question, one of  “Zeno’s paradoxes,” is sometimes framed the opposite way, which I think makes more sense. Before I go from A to B, I must get halfway. Before I get halfway, I must go 1/4 of the way. Etc. Since Zeno didn’t think you could perform infinitely many actions (cross infinitely many points) in finite time, motion should be impossible. Clearly not how the universe works, which is why it got called a paradox. 

        1. Found it. It appears to be just the one study, and I’ve found at least one criticism of it (which, to be fair, does not appear to be written by a scientist) for using a nonrepresentative sample. If there’s any other scientific literature out there on this, I’d be interested in seeing it.

  2. I think there’s a simpler explanation for xenophobia: strangers can kill you. If there is in fact a genetic basis for xenophobia, it would have developed when humans lived in small tribal groups. And one characteristic of human tribes is that they frequently wage war on one another. So it would make sense for humans to develop an inherent distrust of people belonging to other tribes. 

    1. yep, I think that’s really “the point”.   genetic_distance between individuals is going to be proportional to the amount the individuals are going to look out for each other.  going into the negative sense when resources are limited.

      what really gets the evolutionary biologists into head-scratching mode is the guy that jumps into the frozen lake to save a dog that he doesn’t even know (and then maybe dies doing it): the altruism paradox.

    2. Absolutely. It’s why racism and the tendency to war is not learned, it’s an inherent part of human psychology.

  3. Xenophobia is neither the fear of Xeni, nor of Xena.

    Nor Xenu. Zeno-phobia is a hatred of mathematical paradoxes, while zine-ophobia is an aversion to amateur, low-circulation magazines.

  4. The best part about Xenophobia is having less of a likelihood of being impregnated with chest bursting aliens.

  5. I remember an online study (maybe read here?) that showed that people generally were repulsed by and avoided people who looked a certain way: pale/pasty/sweaty etc.  because there was an instinctual link between that appearance and illness.  Iirc, you could take the test yourself online by viewing a bunch of photos of different people.

    1. I used to have a friend who would throw up if an ugly person said the word cheese.

  6. I really dislike this kind of argument made by scholars of evolutionary processes.

    It looks to me like their process is this:  (1) observe some trait of humans or human societies that they reckon to be currently disadvantageous, then (2) hypothesize how things may have been different in the past such that the trait was actually advantageous.

    But this seems like a silly exercise to me for a few reasons.  First, I suspect they’re mostly guessing at how life was in the past.  Second, they’re guessing about if/how the trait in question would have actually been sufficiently beneficial to show up in the modern genome.  Finally, there’s typically no practical way to test the hypothesis.

    So while the exercise might technically be part of Bacon’s conception of the ideal scientific process, it doesn’t strike me as a very useful endeavor.

    1.  You make some excellent points.

      The same things had occurred to me while reading the article.

      One particular thought that struck me was punctuated events, like the Toba Catastrophe, which would have turned the whole competition theory right on its head (At least until the coalesced breeding pool of surviving humans grew to the point where it could again begin to cleave.)

      1. I could believe that, but I never felt like I’d looked into it enough to to form a fair opinion.

  7. (there is an actual question at the end of all this, I swear) Maybe it gets a little muddled using humans as an example, but I refrain from eating my siblings, and may even help them, because if I die childless, but they survive and have children, I can still ‘win’ DNA-wise, albeit less so.  By the same token, in the spectrum between mating with my sister and mating with someone who shares almost none of my genes (within that .00001% that makes us different), it’s a more canny move from the propagation-of-DNA perspective (in the short term) to err on the side of incest, in the abstract. A savannah human wouldn’t need a mirror, or even a still pond, to substantially glean her own phenotype.  If Lucy – a savannah human – has to compete for resources, mating less and competing more with people of a different phenotype makes sense DNA-wise, because those people are likely to share fewer genes in common with her.

    But say it’s cold where Lucy lives, and everyone is shrouded in mammoth skin.  Morphological sameness could still be extrapolated – and unconsciously exploited for ‘family style’ DNA-maximization – from proximity.  The further Lucy has subjectively traveled from her place of birth, or from her tribe/family’s current digs, the more she can err on the side of competition with people she meets.  Lucy, before boats, horses or cars, is more likely to be related to someone the less she has to travel to encounter them.   Even if this is true only 50.00001% of the time for Lucy, her xenophobia is adaptive. 

    But Civilization, maybe even just agriculture, made it such that the benefits of cooperation for humans, even with complete strangers, increased your chances of survival and reproduction a thousandfold.  And now Lucy’s hedge bet against strangers seem ludicrous.  But we were already our full-fledged, present-day human selves by the time civilization rolled around.  And we are the same ‘animal’ now as then. 

    Long way to go for this – but my question is – couldn’t bat MOBILITY (in addition to disease) be a factor?  If bats were to suddenly become significantly more mobile across the continent, but the net value of roosting together, for protection, warmth, whatever, stayed the same, you would expect their ‘kin’ metric to go haywire, and for bats to become less social, right?  Bats hitch rides on the transportation technologies of a high-tech civilization (cars, big rigs, freighters, planes even).  And as far as I know, bats are more hibernators than migrators. The travel and the alien setting alone might be enough to trigger anti-social xenophobic behavior across the board (imagine you’re the only Martian on Earth.  No use cooperating with the Earth-lings, DNA-wise).   Or alternatively, because bats are getting 21st century travel without any of the survival/reproduction benefits attendant to civilization, maybe a new niche is being made for what would otherwise be hyper-competitive bats. 

    Two bats from Alaska (is there such a thing?) suddenly and inexplicably find themselves in Chile.  Bat A is genetically inclined to cooperate. Bat B is more competitive.   So competitive, in fact, that he kills and eats nearby bats, including his siblings (it’s my hypothetical).  As a result, Bat B eats more, survives longer, and has more children (with those bats he doesn’t eat) than Bat A, because he’s competitive.  But in Alaska, Bat B was losing the DNA game.  Bat A won in Alaska, because his family tree included more branches.  Even if he and his siblings were each INDIVIDUALLY less successful than Bat B, together they preserved and spread the genes they shared in common more effectively.  In Chile, however, Bat B wins, because he’s not closely related to any bat there.  Bat A’s cooperation is wasted DNA-wise.  Bat B doesn’t even need to encroach on the docile native Chile bats with some cannibal rampage.  Maybe he’s not even a blip on their radar, and the Chile bats who are cooperative are still doing just fine for themselves, because they’re helping a common gene pool.  That shouldn’t even matter.  Bat B is doing better than he was before, and unless he’s unlucky enough to accidentally get shipped back to Alaska, his children, as long as they remain a minority in Chile, will still do better than they would have in Alaska.  Maybe Bat B’s family will eventually reach a critical mass in Chile, where it’s likely enough that any given bat there is moderately related to Bat B, and worth mating/sharing with.  But until then… 

    The idea is that if new batches of bats find themselves in alien surroundings across the country often enough, there will be a minority in every population for whom competitive inclinations will pay off big, because they are genetically unrelated to the population at large.  I’m not saying the bats are doing any of this consciously.  I’m saying that a bat who is already too much of a loner is penalized less for that fault when displaced into a group that is only related to him by species. The loner at heart (as distinguished from adaptively xenophobic) bat’s grandfather was penalized where he came from – even if he ate enough and mated, he would never spread his DNA as effectively as those bats who helped their kin at the cost of some competitiveness.  But if you transplant the loner and his children to a new setting where they are a minority, they can do better for themselves statistically – even if they don’t cannibalize the locals – and even if they still aren’t doing as well as the cooperative majority.  And the median shifts.  Thoughts?  (way way too long, I know)

    1. Your hypothesis holds some water, so long as the situation is ‘Lone bat displaced to larger breeding pool’.

      If, however, the Chilean population were also similarly impacted, due to whatever situation, my money would be on Bat A, since his contribution to the pool would now be proportionally significant, and survival/prosperity of the group would be advantageous in the long term.

      Bat B would actually prove a liability to the breeding pool, as would the similar behavior of any offspring.

      (I’d make an analogy to Cain and Abel, but this IS Boing Boing, after all. ;P )

  8.  Suspend disbelief, my friend.

    Only with an open mind and a hungering curiosity can the voyage of discovery truly begin.

  9.  It wouldn’t be modern “xenophobia” that gets passed on, in the sense of deliberately disliking people who have a national origin other than your own, but more like “a tendency towards caution in the presence of novel persons.” Then there would be people who have the opposite tendency, towards outgoingness in the presence of new people, and that trait would have its own benefits, and at any given time one trait would be more useful than the other.

  10. You commenters not afraid of Xeni? You should be. She could take you in a fight, all at once. Without even noticing, like it’s a hong kong action movie. If she’d noticed, you’d be dead. When Jackie Chan has nightmares, it’s about fighting Xeni.

    I heard she once punched a dude’s bones RIGHT OUT.

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