Science as a social construct: arachnophobia


Script below the fold:


In response to an obnoxiously common attitude that science is all about truth and reality and all those good things, this is the first in a video series that attempts to explain some problems with that pollyannaish idea — that actually science is a philosophy that tries to build a coherent model of how the world works with empirical evidence, but that it is done by human beings who have flaws and biases and who tend to impose unwarranted levels of certainty on certain interpretations, and that in particular we tend to attach greater meaning to conclusions that favor conformity to cultural assumptions on the evidence.

We also have a framework, or lens, through which we view the world, and we tend to take it for granted. For instance, I have scientific training in neurobiology, genetics, development, and evolution, and I’m also an atheist with an ultimately reductionist perspective — there’s nothing but matter, energy, and information in the universe. That means I’m perpetually tempted to just assume phenomena can be distilled down to interactions between atoms, and I definitely am confident and believe that that is true, but what I can’t justify is the assumption that we, as scientists and human beings, KNOW how all those interactions work. We don’t. The one thing we know for sure is that they’ll be far more complex than we expect, and that there will be surprising and unpredicted side effects and causal connections.

Far too many people confuse science, which is a process for investigating reality, with reality itself.

This is quickly going to become a tangled argument because, in addition, our modern culture tends to favor scientific explanations, so it’s really easy to get in a loop. Scientists search for evidence that, for instance, our culture is the superior human culture, and then society turns around and claims that the idea that their culture is superior has now been reinforced by Science, which then increases the incentive for scientists to bolster that bias. And it goes on and on until you’ve got loud nitwits in the public sphere proudly announcing that it’s a scientific fact that Africans have an average IQ of 70.

This is not to argue that flat-earthers and creationists (or “scientific” racists) have valid points, or that science is merely a matter of opinion: they don’t, and it isn’t, and there are levels of certainty, and the age and shape of the earth are not debatable conclusions. But some aspects of science have acquired a kind of epistemic arrogance that has been seized upon by certain deplorable aspects of society as an excuse to make extreme claims of confidence for what are actually unsupportable claims, and are using those claims to complete the loop and propose some ugly changes to our social environment.

I’m going to start off gently, with a topic that probably won’t shock you or trigger raging denunciations from the Status Quo Warriors of YouTube. Let’s talk about a simple phenomenon that tends to get painted with unfortunate levels of genetic determinism.

Arachnophobia

The instigation for this video was my curiosity about arachnophobia — I seem to totally lack it, and am instead fascinated by spiders, but when I started showing off videos of my current research interest in the lovely Parasteatoda tepidariorum, I got comments and complaints from people who blanched when they saw a mere picture of a spider.

How interesting, I thought. I wonder why people have such deeply different views on something as common as an ordinary resident of our houses. I wanted to look this up — not because I wanted to justify throwing closeup photos of spiders at people who didn’t want to see them, but because I honestly wondered how this kind of phobia could arise. So I turned to the scientific literature and other sources, and tried to find out what the root causes were.

I was not surprised to find some sober and reasonable explanations in the scientific literature, but what was disturbing was how rapidly the explanations drifted into absurd genetic determinism the farther you went from the serious work in neurobiology — oddly, while the scientific literature is rather ambiguous and acknowledges that phobias are a complex phenomenon, as you move into pop psychology magazines, the reported frequency of arachnophobia begins to rise, and you get more articles telling you it is a primordial response in evolution and has a significant genetic component, and by the time you get to the tabloids you’ve got nonsense like “Phobias may be memories passed down in genes from ancestors” and “Humans are hardwired to fear their angular legs and unpredictability”.

The various popular science websites aren’t immune, either. “We Really Are Born With a Natural Fear of Spiders And Snakes, New Study Shows”, says Science Alert. I read the study — no, it doesn’t show that. It’s not a bad bit of research — it shows that a small sample of 6 month old babies show a stronger pupillary response to spiders than to flowers, but it’s being overinterpreted. TechTimes is even worse at describing the same paper: “Researchers Uncover Genetic Roots Of Fear Of Spiders”. No genes were examined in the study. No genetic analysis at all was done. How can you talk about genetics when they didn’t even look at heritability or familial relationships?

Another strategy is to invoke evolution, specifically selection. Spiders are a threat! They’re dangerous! Therefore, it was advantageous to have a strong aversive response to them, and we can assume that Nature has equipped us with an automatic danger avoidance mechanism in arachnophobia. One of my sources even says this:

One prominent theory states that early on in human evolution, spiders posed a threat, so we’ve developed a sort of hair-trigger reaction to them.

Curiously, while it’s called a “prominent theory”, they don’t provide a reference. It is simply assumed that spiders have posed a threat, and that of course natural selection has saved us from it.

One problem with the theory, though, is that spiders are not and have not ever been a serious threat. There are venomous spiders that have the potential to do people harm, but the thing is…they don’t have any interest in biting people. People are not their prey. People sometimes try to harm spiders, sometimes as a byproduct of arachnophobia, which leads to them getting bitten in self-defense, but honestly, they are an inconsequential hazard.

I tried looking into the spider-caused death statistics. One problem is that they’re so rare; you’ll sometimes see the number 6 thrown around…as in, there are about 6 deaths from venomous spiders in the US in a year, but even that falls apart when examined closely. One of the scariest spiders around the US is Latrodectus, the black widow spider. Fear that red hourglass! but there are only 3, count ’em, THREE reports of deaths by black widow envenomation in the entire world medical literature in all of recorded history. None of them have occurred in the US.

Another so-called deadly spider are the South American wandering spiders. How many fatalities have they caused? 10. Only 10 in the entire recorded history of Brazil. Ten is not nothing, and it would be very wise to avoid the risk of being bitten by Phoneutria, but it’s clearly not a danger that should make Brazilians tremble in fear. That Bolsonaro primate running the country is far scarier and will end up killing far more people.

The Australian Redback is a relative of the black widow, and as we all know, everything in Australia is trying to kill you, so I was a little surprised to find this headline from 2016: “Young man is first to die from spider bite in Australia for 37 years”. The poor man actually died from an infected spider bite, not the venom, so there is that: a general aversion to biting arthropods is a useful property. They hurt, they can lead to infection, and even tiny creatures can cause deadly infections. But mosquitos kill a million people every year. In the general category of entomophobia, it seems strange to single out one group, the spiders, with a specific label of arachnophobia, especially when you consider that spiders kill mosquitos which kill millions, or to think that we’ve evolved a genetically determined response to a specific organism in the absence of any selective advantage.

Being bad at risk assessment is not a sound foundation for an adaptive explanation.

I mean, we have strong evidence that leopards were significant predators of our hominin ancestors, with traces of big cats gnawing on their skulls. We know that even today, leopards are dangerous to baboon and chimpanzee troops. Shouldn’t we, by that logic, have ailurophobia burned into our genome? But no, instead we’ve become raging ailurophiles. No one has ever, as far as I know, sent a worried and regretful email to a website owner asking them to please stop showing so many pictures of cats, because it makes them queasy. Ailurophobia seems to fade easily into ailurophilia, which ought to tell you something about the malleable and experiential nature of these things that some people would like you to believe are hardwired by an inbuilt ancestral and genetic memory.

Does this imply that there is no genetic foundation for phobias, or that I believe people are blank slates or infinitely malleable, that common caricature of people who don’t accept the omnipotence of genes? No, not at all. There is good evidence that there are genetic predispositions to some kinds of phobias, but that they’re the product of both genetic factors and experience, and also, that they’re not quite as specific as some have argued: that there may be a general predisposition to animal phobias, for instance, but that fears of specific animals are shaped by personal histories. So someone might inherit a tendency to shy away from animals in general, but could have had a happy childhood with beloved pets and be totally into working at the humane society; someone else could totally lack any genetic bias to fear animals, but after a single intense traumatic experience with bats, he grows up to be Batman.

Here, for instance, are the results of a twin study done on over 4,000 twin pairs in Virginia to assess the heritability and environmental influences on various phobias. I know, it’s a complicated tangle of numbers, but all you have to know is that BOTH genetics and environmental effects are important in every one of the phobias. They went further and looked for correlations between phobias — for example, is there just one general heritable “phobia proneness” trait, or is each one of these independent and specifically regulated? — and found that neither extreme is true. They found four rough clusters of traits that imply perhaps four general causes; arachnophobia is part of a correlated package that includes other animal phobias, like fear of bugs, mice, and bats, and also, interestingly, includes social/agoraphobic fears. We’re all just animals, I guess.

Again, remember that the causes are multifactorial. You could have a genetic bias to like animals and social situations, and still have been conditioned to fear spiders.

There’s another level to this story — many levels, in fact — and that is the difficulty of translating genetic information into the organization of the nervous system. The genome is most definitely not a blueprint. It does not specify, for instance, the morphology of brain nuclei. There is no map of the connectivity of the brain somewhere in the genome. Rather, the genes establish a pattern of potential responses of cells to environmental stimuli, and the final pattern emerges as a consequence of mostly roughly predictable interactions between genes, cells, and the environment.

I’m always stopped cold at statements about how something as specific as recognition and fear of spiders can be encoded in the genome — it’s challenging enough to see how a network of genes can generate the rough outlines of a brain, setting up reward and fear nuclei and pathways, without proposing that a search image of a specific kind of organism can be propagated through the complex and mostly indirect series of cellular interactions that end in the result of clusters of cells and pathways.

Fortunately, neurobiology doesn’t make such claims. Rather, the models for phobias involve development of a common neurological substrate for fear processing in the brain — substrates like the basolateral amygdala, connections to the locus coeruleus and the nucleus of the solitary tract, and generating and receiving endocrine signals. The brain builds complex circuits that interact to create a general property we call “fear” (we could speculate endlessly about what “fear” means to an organism), and we could imagine that there is some degree of variability in the sensitivity of these circuits that lead to individual variation.

The consensus is that the specific details of a phobia are fine-tuned by experience. There isn’t a specific spider-phobia, but there may be a general predisposition in some individuals to have, for instance, a disgust response to contamination, small animals, vermin, etc., that can be shaped by history and events in an individual’s life.

There is a non-experiential, innate fear that is the product of common neuronal circuitry found in essentially all human beings. There is some degree of variation in this circuitry: some individuals will be more or less sensitive to activation of this network, and others will vary in how readily they habituate to fear stimuli. There is a normal and healthy level of function: sure, you should be hesitant to handle a spider or a creature unfamiliar to you; that’s what this circuitry is for. There are also levels of dysfunction. Failure of this network can lead to a non-adaptive embrace of dangerous novelty; hyperactivation can lead to self-destructive excessive reactions to relatively harmless stimuli, like arachnophobia or PTSD.

Most fears, and the degree of our responses to them, are experiential — they involve modulation of the common fear circuits by our experiences and history. But they are no less real for that. We have plastic brains that respond to our environment and generate physical changes in our nervous systems that are just as significant and just as genuine as the wiring we’re born with. I was not born loving my wife and children; I was born with the capacity to love, and who and how I learned to love certain individuals was constructed. That doesn’t make them less real.

You can no more tell someone that their fear of spiders is an epiphenomenon, something that is generated by their experience, and therefore inconsequential, than you can tell me my love for my kids is epiphenomenological and can be easily over-ridden. Experience is real. Your feelings are valid. Whether they’re hardwired or learned is irrelevant to their significance to the individual. Science doesn’t and shouldn’t favor one or the other, especially since the lessons of genetics and neurobiology and development have been clear that genes and environment are tangled in a feedback loop that makes it impossible to dissociate one from the other.

It’s ironic that the people who are paying the loudest lip service to a reductionist version of science fail to recognize how much of their bias is emotional.

“Facts don’t care about your feelings”

It’s true, they don’t. What is not being taken into account is that feelings are also facts that have to be addressed. Feelings are physiological. They’re part of the equation, and maybe the biggest part — there’s less genetic variation between people than there is cultural and personal, yet somehow we’ve ended up in a situation where the primacy of a narrow (and conclusively false) interpretation of human nature is labeled “scientific”, while the richer, deeper, more complex knowledge of humanity that has been assembled by biologists, psychologists, sociologists, and anthropologists is dismissed as politically and ideologically motivated “feelings” by an assortment of science denialists and anti-science propagandists.

This is what I find fascinating. In popular culture, there’s a kind of general drift towards claiming genetic determinism as a scientific fact. We shift from an observable fact — that some people do have a genuine fear of spiders — to an unsupported opinion — that arachnophobia is a genetic condition — and ignore all the science that says it’s a product of experience shaping a general neuronal substrate to favor a harder version of the story that privileges the notion that it’s a genetic trait.

Why? I have a couple of potential explanations.

One is that science has become the undeniable authority on reality — it’s the new “goddidit”. You don’t have to actually know any science to be able to use the claim that “Science says…” to justify your opinion, just as you never needed to know the actual opinion of a deity to be able to claim he supports you. It’s a handy shorthand that I’m seeing a lot of far-right, alt-right, and centrist science abusers throw around. It’s particularly amazing how they can tell me that, for instance, because I reject the nonsense of pseudo-scientific excuses for racism, I must therefore be a creationist.

Second is that there is a twisted idea of responsibility here. You can’t help what you’re born with, but if you have an acquired disability, well, that’s your fault, and you’re fair game for discrimination. You’re afraid of spiders? Too bad. Here’s a bucket of them, get over it.

I’ve witnessed people mocking others for PTSD…people with no qualifications in psychology or medicine, with distorted ideas about what PTSD is or its causes, and who treat it as a sign of weakness. Acquired disorders are a sign that you are inherently flawed, that you are somehow inferior. That you are damaged by nature, rather than that you’ve been overloaded with damaging environmental inputs.

Third, there is a sense of self-justification. I am well-off, I’m not being discriminated against, the system is working well for me — while for someone else, they are poor, they are suffering, the odds are stacked against them. Which is better for my self-esteem? To claim that it must be because my genes are intrinsically superior while their genes are inferior, or to argue that both of us are in our respective positions because of fundamental biases in our environments? It’s especially troubling when we note that those environments are perpetuated by individuals with self-interest in preserving the status quo — it’s not a difference in genetics, it’s that my privilege is helping to produce your disentitlement.

That’s our situation. The media, politics, and popular opinion are overrun with invalid, absolutist notions of the omnipotence of genetic explanations. All I can do is try to explain why they’re wrong.

Simplicity and certainty are for Nazis. Complexity and nuance are for Lefties. And scientists.

Next in this series, I’ll try to explain the confusion between alleles and traits…a confusion that scientists have contributed to repeatedly for the last hundred years.

A few references:

The bad:

https://www.techtimes.com/articles/44425/20150406/researchers-uncover-genetic-roots-of-fear-of-spiders.htm

https://www.sciencealert.com/deep-unshakeable-fear-spiders-no-random-quirk-fate-born-arachnophobia

https://www.telegraph.co.uk/news/science/science-news/10486479/Phobias-may-be-memories-passed-down-in-genes-from-ancestors.html

https://www.dailymail.co.uk/sciencetech/article-2158452/The-shape-fear–spiders-scare-Humans-hardwired-fear-angular-legs-unpredictability.html

The good:

The structure of genetic and environmental risk factors for fears and phobias

Neurobiology of fear and specific phobias

Comments

  1. ftltachyon says

    Makes sense to me. My wife loves spiders. I probably like them a lot more now than I did before I met her!

  2. John Wilkins says

    my curiosity about arachnophobia — I seem to totally lack it, and am instead fascinated by spiders
    Yeah, but you’re weird; you liked looking at your musculature when you cut your hand if I recall.

  3. Owlmirror says

    we have strong evidence that leopards were significant predators of our hominin ancestors, with traces of big cats gnawing on their skulls. We know that even today, leopards are dangerous to baboon and chimpanzee troops. Shouldn’t we, by that logic, have ailurophobia burned into our genome? But no, instead we’ve become raging ailurophiles. […] Ailurophobia seems to fade easily into ailurophilia, which ought to tell you something about the malleable and experiential nature of these things that some people would like you to believe are hardwired by an inbuilt ancestral and genetic memory.

    Ah, but don’t forget the potential effect of widespread Toxoplasma gondii infection . . .

  4. says

    Science and religion are both philosophies that try to explain the world. Religions relies on anecdotes which have very limited predictive value. Science is based on objective empirical data which confers significantly higher predictive value and accuracy [albeit, colored by human bias and limited by scientific methodology]. In the past, the power elite were able to use religious narratives to present themselves as saviors to ignorant common people. And while ‘modern culture tends to favor scientific explanations’, there is still a large population of modern people who prefer their irrational in-group narratives to scientific predictions.

  5. John Morales says

    Skeptical Partisan:

    Science and religion are both philosophies that try to explain the world.

    Such simplistic vacuity!

    Allow me: Science is a pragmatic methodology based on a particular epistemology; religion is a superstition, and philosophy is the study of knowledge.

    (how, why, and whether)

  6. nomdeplume says

    Arachnophobia seems to me to be likely to be a learned response – there is a constant barrage of warnings from parents and media, fromthe moment you are able to understand warnings as a small child. Snakes seem to me possibly a different matter. I wasn’t warned about snakes as a child (there were none where I lived) but nevertheless I get a gut reaction, fight of flight, not only whe I see a snake, but when I see a curving shape of the right thickness. Other animals I think also lack fear of spiders (except as a food source!), but do have apparently instictive reaction to snakes, either avoiding or trying to kill them. I don’t think you could “hard wire” snake fear into the brain through evolution, but perhaps fear of a sinuous shape might be an evolutionary advantage, in the way fear of heights, or deep water, probably is.

    Lack of fear of leopards seems to me in a different category. How, and why, would leopards be distinguished from other big cats, or indeed dogs? Fear of something with sharp teeth running at you on the other hand might well be innate, in the same way as birds react to a hawk shape overhead, but not to other bird silhouettess, or fish react to a shadow on the water.

    Interesting tooic, thank you PZ, look forward to next one.

  7. unclefrogy says

    hmmm I am not generally afraid spiders but i will have a very strong negative reaction to unexpected black widows, finding them where I do not expect to. Some times I get startled when I unexpectedly find other types of animals as well especially animals I have never ever seen before (arachnids mostly) though I do get scared when i accidentally corner a skunk.
    I wonder if the root of the phobia is not the unexpected encounter, many animals seem to have that kind of response?
    things are complicated indeed.
    uncle frogy

  8. jrkrideau says

    I don’t remember even hearing about arachnophobia until I read about it here. I live in a fairly northern climate where spiders are tiny and essentially harmless.

    I remember having one live on my bedpost for a year or so when I was a teenager. I was quite fond of him/her. I did have to fight my mother off a couple of times when she noticed the web.

    @ 9 nomdeplume

    Where I grew up we had everything from 5 cm “cute” snakes to 3 metre things. None dangerous.

    I was not impressed to nearly step on a 3 metre black snake in my bare feet or to accidentally grab a 1 metre snake while climbing a tree as a 10 year old.

    Strangely enough while I am snake adverse I really don’t fear them. I am much more adverse to pictures of snakes. If you saw the original “Raiders of the Lost Ark”, I spend about 30 percent of the time clutching my girlfriend’s hand and asking if I could open my eyes.

    On the other hand, I have been known to stop traffic while we got a snake off the country dirt road. Drivers have always been very friendly and helpful.

  9. nomdeplume says

    Incidentally the Redback is the same genus as the Black Widow. The reason it is feared (apart from the toxic venom) is because it is often abundant around houses and sheds, and often nests in situations (in upturned plant pots, under pieces of metal, in wood piles) where it can be easily encountered accidentally. There is a country and western song called “There was a redback on my toilet seat”, which escalates the fear level!

  10. slithey tove (twas brillig (stevem)) says

    One hypothesis I read a while ago, was that the arrangement of legs on a spider “short circuits” one of the “shortcuts” our brains have developed to anticipate the direction a potential threat may take. Being optically radially symmetric we are left with completely uncertainty as to the direction it may take. Which is enhanced by the observation that they do move in all directions equally. The “predictability” of quadropeds makes them slightly less threatening than the octopodal arachnid.
    thank you for reading

  11. says

    John Morales: Thank you for such an edifying and enlightening comment… now please provide a comprehensive and comprehensible explanation for adult foreign language speakers with roughly a third grade education in their native language. I always seek to improve communication with my frequent audience.

  12. m n says

    @ nomdeplume #7

    It’s definitely possible that a heritable disposition to be more likely to fear snakes is a thing, but I wouldn’t think it’s anything like universal in humans.

    To counter your anecdote with another anecdote, I grew up where there were dangerous snakes around (rattlesnakes, coral snakes; cottonmouths when I was a bit older) and even learned about how dangerous they were in early elementary school and from relatives, but I’ve never been afraid of snakes. I’d keep a healthy distance while looking, but I was always excited to see a rattlesnake while hiking; they’re so cool!

    I am, however, afraid of spiders (though not, I would say, in any innate way, as I decidedly was not prior to having a wolf spider drop down my bikini when I was 12 or 13).

    I have a sneaking suspicion that both familiarity or the lack thereof AND traumatic experience can play a part in phobic responses. A lack of familiarity can generate fear, because the unknown and poorly understood is more frightening than things we know how to deal with, and this lack of knowledge, specifically when we know only a little and that little bit is “sometimes dangerous!”, can lead to an outsized fear response. Then, also, an intense experience can cause trauma and a learned fear response.

    Thus, because I was educated about snakes as a child and never had a traumatic experience with one, I hadn’t an opportunity to develop a phobia towards snakes; but having had less information about spiders (at the time I think what I knew about wolf spiders was: 1. Painful bite, 2. Mom hates them) and having had a traumatic experience with one, I was primed and ready to develop a fear response towards spiders.

    This isn’t to say that a heritable disposition to develop certain phobias (or just phobias in general) isn’t possible, just that I don’t think it’s remotely feasible to say that that’s likely the only factor.

  13. wzrd1 says

    A good chuckle is, not all that long ago, science was a philosophy. Then, science went toward evidence, rather than seeking evidence that confirmed a belief, but what evidence revealed.
    The US was Johnny come lately to the table and with a longstanding anti-intellectual undercurrent that even Azimov observed.
    Once, it was, what you saw, I consider sawn by me. Wrong answer.
    Hence, why science loves replication.

    <

    blockquote>There is some degree of variation in this circuitry: some individuals will be more or less sensitive to activation of this network, and others will vary in how readily they habituate to fear stimuli. There is a normal and healthy level of function: sure, you should be hesitant to handle a spider or a creature unfamiliar to you; that’s what this circuitry is for.

    <

    blockquote>

    Indeed!
    As you mentioned previously, the “blueprint” isn’t a solid clonal system, but a guide to a total organism. Graduations of tissues in specific locations is important, not always critical, hence the occasional error the occasional teratoma.
    More often, things work amazingly well. Not a clone, which would inherit errors and eventually grow extinct, but some errors improve survival.

    Acquired disorders are a sign that you are inherently flawed, that you are somehow inferior. That you are damaged by nature, rather than that you’ve been overloaded with damaging environmental inputs.

    Yeah, bullshit on rye, served up as a Reuben sandwich.
    I know a lot of individuals far superior as richly experienced, welcoming individuals who are pillars of their community that have PTSD. Calling that a genetic flaw, in the absence of family members (typically absent in the idiots calling it genetic), is nonsense and not reflected in any real metric that has been measured.
    Meanwhile, such an idiotic notion is disproved, via US Armed Forces data, psychological evidence and medical observations.

    Third, there is a sense of self-justification. I am well-off, I’m not being discriminated against, the system is working well for me — while for someone else, they are poor, they are suffering, the odds are stacked against them. Which is better for my self-esteem?

    True, but I don’t judge people who choose to masturbate with a cheese grater. One can feel self-justified, but so do mass murderers, as history has so well provided proofs of.
    I’m not discriminated against, I still manage to not manage to not rape my neighbor’s cat, wife, child or neighbor or commit any atrocity. Indeed, when a house guest managed to “drop a mickie” into our water glasses, I haven’t hunted the bastard down after he raped my wife. I did alert the community, who likely will address that issue, but I didn’t suggest any course of action.
    Although, I did suggest that the level of offense was quite high. I’m not some mythical and perfect god, someone harmed another in a way that is obscene. Did the very same thing in other situations where my wife wasn’t involved.
    But then, the poor are ignored, so our Constitution and laws are largely optional.

    Simplicity and certainty are for Nazis. Complexity and nuance are for Lefties. And scientists.

    Well, if that was true, the idiots would lack any form of machine or chemistry. And based upon that, they wouldn’t have firearms. Or computers. Or electricity. Or live in a damned frigging house.

    As for the original premise, as discussed by PZ, can’t agree more. With some qualms on modest biological issues. And those quibbles are so modest, that likely, neither us would be annoyed as to being right or wrong.

    After all, science is only opinion, as measured to six sigma.**
    I doubt I need to further proceed.

    Time for humor.
    I have a gun! And can’t find a single frigging grease point, what in the actual fuck is going on?*

    *Grease guns, there were the rare military submachine guns, then there were the far more common grease guns, to lubricate bearings.
    Of which are becoming nearly extinct, due to “permanently lubricated bearings”. Yeah, their life ends due to lubrication failure.
    As for the military weapon, I would enjoy a chance to fire one, but would be utterly unlikely to actually enjoy it. I’m a precision marksman, using calipers to measure the distances between paper perforations is my preference. That’s simply an ancient, but notable, weapon of war.
    I use military specific weapons in semiautomatic mode in competition for prize.
    I use other weapons to hunt for meat, usually, not even bothering to load the weapon.
    But, if a deer presented itself, in season and with license, I have no problem lowering my meat bill and filling a deep freezer.
    Annoyingly, the last time I saw a white tailed deer in the licensed hunting grounds, she had a small fawn and it was buck season.
    With odd cards hung on trees and browsing level plants, “On vacation in the Bahamas, be back after the season has ended”. ;)

    OK, in hunting, the reality is, idiots shoot up the woods, game knows what time of year it is and head distant from roads, idiots make reasonably accessible roads areas sound like the fucking deer are shooting back.
    I’ve even heard multiple sonic booms caused by high power rifle rounds passing overhead and some trimming tree limbs.

    But, with firearms, my firearms serve multiple purposes. Dust collection inside of their safe, the primary usage. Secondary usage, successful competition with other marksmen/women, to win a cash prize or more welcome, specific food prize (turkey or ham), the latter’s bone(s) used in creating wonderful soups.
    After, said weapons go back into the safe and are forgotten until half year maintenance interval, where drudgery with carcinogenic compounds are engaged in to clean and lubricate my investments.

    **Yeah, seriously high levels of evidence is required today. My first sentence reflected the history quite poorly, Albert Einstein had a philosophy degree in a rather hard, mathematical science.
    His largest contribution was adding Lorentz into his notions of calculations.
    His “correction” for Newton to correct for Mercury’s orbit, well, yeah, likely an error.
    Lacking his first wife, another physicist, he entirely emitted nothing beyond personality.
    Which is something that I do respect, his pacifism. After running away, which is understandable and I’d support him.

  14. nomdeplume says

    @13 I should have added that I have spent my adult life in places with very deadly snakes. Have had a number of very close encounters of the Australian Brown Snake kind. This has certainly enhanced my healthy respect, and perhaps my snake phobia. On the other hand, also plenty of redbacks here as well, and while I am cautious when picking up, say, an old plant pot, I don’t have any fear of spiders at all, and take great interest in their fascinating activities. My wife does have arachnophopis, very strongly, and I have to carefully remove intruders with the aid of a glass jar and piece of cardboard!

  15. brucegee1962 says

    I recollect that in school, I was taught that other animals, particularly those that weren’t raised and trained by parents in a herd-like setting, had far more of their behaviors governed by instinct; our behaviors, on the other hand, rely more heavily on what we are taught. I’m certainly willing to believe that my old school taught me poorly.

    I think that the evo-psych crowd, though, looks back at the amazing behaviors that other animals seem to be born knowing, and says that, if they start off with all this pre-programmed knowledge, then perhaps we humans have more of that software hardwired into them than we’re aware of. Here’s what catches me up: baby rabbits know to hide when the shadow of a hawk passes over. Baby anacondas don’t get any lessons from their parents that teach them how to ambush and smother their prey. Baby spiders know how to spin a web without ever having witnessed one. So how do I reconcile all of those behaviors of other animals with this?

    it’s challenging enough to see how a network of genes can generate the rough outlines of a brain, setting up reward and fear nuclei and pathways, without proposing that a search image of a specific kind of organism can be propagated through the complex and mostly indirect series of cellular interactions that end in the result of clusters of cells and pathways.

    If genes can pass down a behavior as complex as web-building in a brain the size of a pinhead, then why is that evo-psych opponents say our own genes can’t pass down similarly complex behaviors?
    Before flaming me — normally I’m as dismissive of evo-psych as anyone else here, but I’m genuinely curious what the counter is for this argument of theirs.

  16. imback says

    @brucegee1962 #16 asks

    why is that evo-psych opponents say our own genes can’t pass down similarly complex behaviors?

    It may be possible that genes pass down complex behaviors, but the point is that you cannot conclude that’s the case without evidence. Requiring evidence is central to doing science.

  17. neptis says

    Thank you for this article, PZ! I’ve also wondered why arachnophobia exists and expressed the opinion that some of it might be cultural in previous comment. This was a really interesting read.

    #16
    From what I’ve learned about animal behavior, you can often break down seemingly complex reactions to simpler rules: taking your rabbit example, it will not just hide from the shadow of a hawk, but also from a pigeon’s or even a paper kite’s. Any moving shadow of a smaller size really.
    Fearing spiders does seem to be awfully specific, because there’s no simple trigger. You don’t get the same reactions when posting bee / isopod / ladybug / housefly pictures, although they are also hairy, have lots of legs, a segmented body, and move unpredictable respectively
    That was enough to give me a pause and make me wonder if it’s really just a genetic response.

  18. hemidactylus says

    Having a resident spider as a shower buddy has me reflecting on my attitudes toward them. I don’t cower in fear over its presence. I think it’s kinda cool. I would hesitate to grab it and let it crawl over my hands. I don’t have a phobia for snakes. Had a few as pets. But my Irwin handling skills are rusty and I am not about to chase one down and get up close and personal. I don’t keep reptiles as pets anymore because contamination fear of salmonella. Disgust? One fear replaces another.

    Is there a fear of “social constructionism”? It’s a gradation thing that gets over-applied without a sense of irony as social construction becomes itself a social construction and the pomo bogey of an overarching narrative. Be careful out there folks.

    Searle’s contrast of brute and social facts is helpful. The latter has a heritage going back to Durkheim. Erroneous phrenology maps were a social construction. That brains do some localization of function is a brute fact. That Adam Smith and Thomas Malthus influenced Darwin shows the socially constructed aspect of evolutionary theorizing. The convergence of Wallace shows something was in the air. But evolution is now as brute a fact as it gets, though much of pop fad evo psych gets by on the reflexivity inherent in social facts shared by adherents. Ideological bubbles.

    So why are there popular fears of spiders? How much is enculturation? Are there sex differences in arachnophobia that could be attributed to how boys and girls are differentially raised? Could there be folkways and mythic disparagement of spiders? As we partly learn our racism from parents as models of how to interact with unknowns could fears of spiders be similar? Could arachnophobia be vicarious and contagious? But if too easily spread how prepared could such fears be even if nonspecific? Or is it more along the lines of adopting the superstition infused ideology of your parents as Dawkins and others say of religion?

    We have no tendency to fear kittens though the primordial image of predatory felines should scare us. After the experience of being bitten by a German Shepherd when young I developed a seriously debilitating fear of strange dogs, but not my own.

    People keep spiders as pets, but how popular are they? My argument against hardwired fear of snakes would be their popularity as pets for people who are not germaphobes.

    As a matter of comparison how many people reduced beachgoing after Jaws? Where would a primordial fear of sharks stem from unless we are aquatic apes (joking)? How many people stopped having kids after It’s Alive made them fear babies? There could be a cuteness factor in the latter. Sure a newborn might kill all the doctors and nurses but just look at the adorable face. Awww! Spiders aren’t cute. They are icky and hide in cupboards and crevices. They are the tiny Other that must be eradicated…hence sprays and pest control companies.

    I have a more rational fear of termites. They don’t look scary in appearance, but they are an economic threat. Pest control companies exploit these fears.

  19. hemidactylus says

    As for PZ’s reflection on science as a lens, I would say without science we see a fuzzy manifest image, but science is a pair of spectacles that greatly improved our vision. I am butchering my second hand application of Sellars’ distinction, but it is apt. Science can work in brute facts. The so-called harder sciences get closer to bedrock. Economics as ideology may demonstrate what Soros considers as reflexivity where application of rational actor models has a self-fulfilling aspect for a time until the bubble pops. So economics has a danger of dealing too heavily in social construction and as propagandized ideology may be weaponized deliberately or at least delude some of its adherents into seeing what they want to be true. Chemistry and physics don’t seem to deal with the same issues of conceptual distortion of the subject matter.

  20. davidc1 says

    @3 All them scientists are weird ,that Jerry Coyne allowed a botfly to hatch out on his head .

  21. says

    It’s not a bad bit of research — it shows that a small sample of 6 month old babies show a stronger pupillary response to spiders than to flowers, but it’s being overinterpreted.

    Such studies always make me wonder if the people who do and talk about them have ever actually met babies in the wild. A 6 month old baby will have had 6 months of flowers. Flowers are abundant in baby-settings. Whether on onesies (even for the boys), wallpapers, rattles, toys, cribs, PJs, “my first picture book”, …
    So at 6 months the baby may well have learned not only to recognise flowers, but also to associate them with good things. Whereas spiders are probably pretty new. There’s rarely a cuddly spider on the play rug and people tend to move them out of the reach of babies, even if only to spare the spider the experience of having its legs pulled out.

  22. stevewatson says

    “a general aversion to biting arthropods is a useful property.”

    Really? I rather enjoy biting certain arthropods, properly cooked and seasoned…..

    (Which shows you how irrational the whole thing is: I’ll happily eat crustaceans, but am repelled by the idea of eating insects, and even touch chelicerates. Except for the horseshoe crab carapace in my collection.)

  23. Jazzlet says

    That being “happy to eat crustaceans, but averse to eating insects” thing bothers me about myself, I know it is irrational, but the thought of eating insects or arachnids is repugnant. I would quite like to know how I would react if fed insects unknowingly, then told I had eaten them …

  24. nomdeplume says

    @16 Tinbergen showed that the response in ducks (I think) was very specific to hawks. Using models “flying” on a wire overhead, he showed there was no response to a model in which what seemed to be long neck moved first ahead of a short body and tail, ie the shape of a waterfowl. When the model was reversed though, so that a short head/body preceded a long tail, the ducklings took evasive reaction. So whether specific phobias can be hardwired may be in doubt, but significant shape recognition certainly can, and this in practical terms, has the same effect.

  25. Pierce R. Butler says

    I tried looking into the spider-caused death statistics.

    Our esteemed host would probably have found bigger numbers had he sought the hurt-like-hell couldn’t-go-back-to-work-for-N-days stats. A tough (though aging) friend of mine spent a month painfully recuperating from a (diagnosed) brown recluse chomping, while plenty of jobs were available and money sorely needed.

    Getting bitten by a horse or falling into a mudpit have low fatality numbers too, but some would recommend avoiding those experiences merely from guesswork and the anecdotal testimonies of those of us who have.

    Living in rural Florida, walking by bushes and fences, tending fruit trees, I plow through multiple webs daily and probably collect several of their inhabitants on clothing, limbs, and head daily – even while trying to leave alone all that I can (including those on porch and in shower). The great majority of local species are both harmless and beneficial, especially in our, ah, insect-rich environment. But my reflex remains to keep/make distance from unknown or scary-looking spiders, and I see no reason to try to change that.

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