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Tears (meltingasphalt.com)
417 points by urs2102 on Mar 20, 2017 | hide | past | web | favorite | 115 comments

Tears aren't excretory or cathartic? Maybe this guy hasn't been through the right kind of situation.

When one of my kids was going through a health crisis I did a heck of a lot of lone crying. Each time internal stress and anxiety would build, my guts would get all churned up, then it would reach the point where I would cry and the "symptoms" would all reduce dramatically before starting to build up again.

I was amazed at the time that crying had such a noticeable effect on physical symptoms. I thought I must be dumping something, adrenalin?, out my tear ducts.

I'm probably wrong, though it's not the kind of set up you can test in a lab.

I don't think his point is that it isn't cathartic; he's pointing out that there is no physiological reason for crying in particular to have evolved to be cathartic. What have leaking eyes or a quavering respiratory system got to do with relieving overwhelming emotions? Nothing. And no other animals experience this.

It's a confusion of cause and effect (or post-hoc fallacy). "I cry because it makes me feel better" supposes that feeling better is the purpose of crying. But really it's the other way around: Crying is the purpose of feeling better. Crying is the thing with purpose, because it's an important and useful social signal. Overpowering urges to succumb to it, and feeling better after having done so, are evolution's way of coaxing our minds to do something that's useful to us, just like urges to eat or have sex, and feeling better after having done them.

It's not really a confusion of cause and effect. It's that most probably there's a cause-and-effect somewhere we don't know. America the landmass did exist before we got to know that it did.

It's quite suggestive that most of the nervous situations can lead up to physiological phaenomena like crying, laughing or stomach pain.

Why do we smile when we're happy? Is it because we're happy (we also expose a similar face when we're scared), or is smiling the purpose of feeling happy?

Not sure if you're arguing for or against my point, but I'd say the purpose of feeling happy is to reinforce the behavior that got you where you are. Smiling (and the compulsion to smile, which few other animals have, though they do feel pleasure) is to signal your state of mind to your peers.

I wouldn't say (and wasn't saying) that the purpose of feeling sad is to cry or engender social signaling (parallel to happiness, the purpose of sadness is downregulation of behavior), but the compulsion to cry itself and the relief afterwards is about signaling.

From: http://science.howstuffworks.com/life/inside-the-mind/emotio...

"The phrase "having a good cry" suggests that crying can actually make you feel physically and emotionally better, which many people believe. Some scientists agree with this theory, asserting that chemicals build up in the body during times of elevated stress. These researchers believe that emotional crying is the body's way of ridding itself of these toxins and waste products.

In fact, one study collected both reflex tears and emotional tears (after peeling an onion and watching a sad movie, respectively). When scientists analyzed the content of the tears, they found each type was very different. Reflex tears are generally found to be about 98 percent water, whereas several chemicals are commonly present in emotional tears [Source: The Daily Journal. First is a protein called prolactin, which is also known to control breast milk production. Adrenocorticotropic hormones are also common and indicate high stress levels. The other chemical found in emotional tears is leucine-enkephalin, an endorphin that reduces pain and works to improve mood. Of course, many scientists point out that research in this area is very limited and should be further studied before any conclusion can be made."

Crying can, quite literally, act like a stress valve!

Maybe those hormones are in emotional tears because that's what's in the blood at the time, same as breast milk containing alcohol if you've imbibed recently.

In other words, tears reflect the body's hormones rather than influencing them.

I want to agree with what you say but "ridding toxins" etc is classic bullshit. You may be releasing some helpful or at least stimulating chemicals in response. You may be activating different neuropathways, epigenetics, etc, even, to play down the buzzword path.

    > but "ridding toxins" etc is classic
    > bullshit
That's exceptionally context dependant, and in this one:

    > First is a protein called prolactin
    > Adrenocorticotropic hormones are also common
    > leucine-enkephalin
You've made the wrong call. I'm all about detoxes being pseudoscience, but you have more than one organ in your body dedicated to ridding it of toxins.

I never cried tears of happiness when the primary sex hormone in my system was testosterone. Now that estrogen is, I cry all the time. Not just from hormones, but also from how happy I am not not be living a lie anymore. And sometimes for absolutely no reason whatsoever. And it's emotionally cathartic as fuck.

This entire thing is so anecdotal and from-personal-experience, it's not remotely interesting in its attempts to generalize.

That's interesting. I've got a colleague who made the same change, and she claims also that crying "as a man" is rare and very hard – as if that pathway is somehow blocked – while it comes very easily "as a woman" when taking hormones and generally helps to relieve bad emotions (or fortify good ones?). If she stops taking hormones for a while, she can't cry anymore.

As a "manly man", I imagine a cathartic cry would help to get rid of deep frustration, stress and anger, but I couldn't cry even if my life depended on it. I'm not an expert, but I feel it's more about nature than nurture – I guess males historically were coping better exhibiting an aggressive "fight" response. It of course leaves men hanging out to dry in situations where an active fight response doesn't help at all, attacking isn't possible and you have to deal with being helpless or hopeless... Cue to male (murder/)suicide.

> but I couldn't cry even if my life depended on it. I'm not an expert, but I feel it's more about nature than nurture

I couldn't either, but after seeing a therapist for some time (for a light depression), I became much more aware of my emotions. Crying became much more easy as well.

Could be a cultural thing this difference in crying between the sexes.

I suspect it is. Look at Chagnon's Yanomamo ethnographies, or at the Homeric epics. Or the Old Testament, or Beowulf, or Le Morte D’Arthur. Men cry at the drop of a hat in all of those.

True -but is present there as a thing for men to aspire to, or recorded as a historical fact?

Seems to me like dumping a chemical out of your tear ducts is exactly the type of thing you can test.

Reminds me of all the historic (and continuing!) confusion around women's sexual health.

How so?

I mean what is the link to tears, just "confusion"?

Also, Victorian attitudes to female hysteria are confounded by JC attitudes towards female sexuality.

Ah, ok - I read the "how so" in the context of GGP post:

"Reminds me of all the historic (and continuing!) confusion around women's sexual health"

I don't think the difficulty in testing that hypothesis is whether your samples have some chemicals in them or not. It's finding a sample population, and the collection of their samples.

That is, it's somewhere in the neighborhood of profoundly rude to approach someone in the midst of terrible grief, all, "I see you're weeping over your loss. Let me have some of your tears for science!"

You could "pre-enroll" people — say, the families of terminally ill patients — to collect their own tears when they do suffer that loss, and weep for it. Even then, though, compliance is going to be difficult to manage. Their priority in that moment isn't your experiment; it's their own devastation. And absolutely rightly so.

Having to stop, or even momentarily diminish, their weeping to fetch the sample kit — do they even have it with them? do they remember where it is? — then open it up (because it has to be sterile, right?) and jab it in their face might also have a materially deleterious effect on the grief-processing role that their weeping in that moment is supposed to provide. If so, that might also taint the results of the experiment, no?

So, no, it's not just a matter of testing for the presence of some chemicals.

(Edited for clarity and phrasing.)

Or you could just find people who are prone to cry at sad films (since I've had kids - me).

Sure. I cry at movies and shows pretty often, too. (The finale of "Six Feet Under"? OMFG.) But that presumes those tears aren't somehow subtly different from personal grief tears.

I really doubt they are, but if we're going to ask the question, it behooves us to get the most accurate answer possible.

I don't think you are wrong. I've had the experiences of deep grief before. Crying and tears can be cathartic; they can also result from feeling something profoundly moving, usually resting on a deep undertone of sadness.

It also sucks when you have a lot of sadness and grief bottled up -- yet for whatever reason, you can't cry.

I will also note: judgement is a subtle form of disgust.

Dr. Eckman has a great Atlas of Emotions: http://atlasofemotions.org/ which is a great starting point for differentiating between the culturally-universal emotions and the myriad of emotional states.

From my personal experience though, the best way to study and make sense of emotions is to experience them. Intellectualizing emotions without experiencing them is not sufficient.

Any number of mechanisms could serve this purpose, though: urination, sweating, blowing your nose. Why should these chemicals leave our eyes? I believe that is what the author is trying to answer.

Many features of human physiology serve more than one function -- our eyebrow ridges protect our eyes from sun, dust, getting punched. I don't mean to reject your idea; but it doesn't seem to go very far towards explaining why tears are the way they are.

Do you have any reason to believe the same chemicals are exclusively in tears (vs feces, urine, sweat, saliva, etc)? Also, it should be easy to do an order-of-magnitude estimate of the effect, even if a chemical is exclusively in tears (concentration * volume). It's highly implausible tears contain anywhere near enough of a particular hormone to affect concentrations across a volume as large as a human body, and deserves some scrutiny/evidence.

I had the same reaction when reading that, but I think the author was mainly trying to make the point that there is no reason a priori to attribute direct psychological properties to lacrimal secretions.

There's a while lot more to crying than just the tears.

It's a key piece to his thesis, and it's tripe. It's like saying exercise can't make you feel better because sweat glands don't excrete excess norepinephrine .

I don't think you understood his argument at all.

What didn't I understand? He insists there has to be a reason why we cry (as understood by tearful weeping) and spends the rest of the article trying to ascribe a social purpose to it. His rejection that crying is therapeutic is a cornerstone to that, and it ignores a whole range of alternate lines of inquiry.

Exercise has a host of indirect (endorphin production), secondary (improved circulation), and tertiary (self-image) effects that improve mood. I think his failure to imagine other reasons for crying are just as limiting as trying to deny those effects of exercise because sweat doesn't contain mood improving hormones or excrete mood worsening ones.

1) He didn't deny that crying is therapeutic in the emotional sense (in that you feel good afterwards); only that the expulsion of tears or the quavering of breath serves no regulatory function physiologically. Just because it feels good after those things happen doesn't mean they caused it.

2) His point is that the urges to cry and feeling good afterwards are evolved instincts to coax you to do something socially useful, i.e. to signal to your kin that you're in distress. The tears and sobbing are the signal; an effect of your emotional state, not the cause of it. The tears are intended to act on your peers, not your physiology. When they've done their job, you're relieved.

In other words, the "symptoms" of crying are probably arbitrary and could have been any number of things that accomplish the goal of signalling, because there is no reasonable physiological connection to the display and the change in emotional state.

3) Exercise is not a good analogy because it has a direct physiological effect on your system. It is exercise which strengthens your muscles and cardiovascular system, not any other activity. Thus it makes sense that we feel internally rewarded for having exercised, because the activity is directly needed in some sense to maintain homeostasis. Compare this to his hypothesis about crying, which is that if its purpose is truly to be a signal, it would have made just as much sense for us to evolve to, say, shiver, or urinate, or faint, or vomit, or convulse, or do any other highly recognizable behavior involuntarily to indicate distress to our peers.

1) Why don't you think it's physiologically therapeutic, too? As I note in another comment, we have to correct drug studies for the placebo effect because we actually get better if we believe we're going to. Breathing changes can modify mood. Maybe this is incorrect, but I'm certainly not going to accept it serves no physiological function without any sort of proof.

2. I believe you are misunderstanding his point, which is, "inherently they're just a piece of social technology, a device for coordinating the tradeoff between dominance and social support."

2b) You undermine your point #1 by pointing out that the "symptoms" are arbitrary. Out of the thousands of possible responses, why tears + weeping? There are more effective signals, and other social animals acknowledge dominance & submission differently. That would suggest crying has a reason beyond social signaling.

3) I don't think exercise is a poor analogy here, but let me be direct: crying could have a direct or secondary neurological effect on mental state that doesn't have an analog in other animals.

That also seems like the stress & anxiety could be causing the other symptoms: crying alleviates stress, which would then ease the symptoms.

The question of why humans cry is always fascinating, since it's such an instinctive behavior we don't seem to realize how bizarre it is. I tried a little to develop a deliberately insane theory to submit to BAHfest (SMBC's festival of bad scientific hypotheses http://www.bahfest.com) and proposed that crying exists to blind us during periods of great emotional stress, since we'd otherwise be prone to irrational and dangerous behavior. Unfortunately, compared with the real attempts to explain tears, it seemed a little too plausible to be bad! When the state of research has someone proposing "we cry because of the soot flying into our eyes at prehistoric funeral pyres," it's hard to be deliberately weird. (I eventually came up with a much funnier topic, so swing by if you're in the area shameless plug etc)

To be fair, I think the soot hypothesis is so terrible it would fit right in at BAHfest.

Frankly I'm astonished it has any credibility whatsoever, and if it does, it would severely dim my view of the entire field.

Across species eye contact is a thing for both carnivore/herbivore dynamics and also dominance hierarchies so if you intentionally wanted to create a weird theory I'd suggest mixing those in weird ways.

So if a hunter gets hurt while hunting he could screw up the hunt for everyone by being hurt except for crying messes up his eye to eye stare down so he temporarily falls to the bottom of the dominance hierarchy allowing the overall tribe better luck hunting and more meat for everyone including himself, therefore cry in pain, in the long run equals more delicious meat. Stalking being more a carnivore behavior than herbivore I'd theorize crying is extremely manly and women carried the trait originally rather than directly benefiting by expressing the trait.

The vegan types can be very vociferous when presented with commentary about the biology of the human body appearing to have evolved to support meat eating, so be careful, its very politically incorrect to look into things like cross species carnivore eye contact behaviors or apparently evolutionary evidence of stalking and hunting biological technologies.

What's the worst that can happen from a vociferous vegan?

Who doesn't want that trophy?

As a parent, it seems like a glaring omission that most crying is done by babies. It's right there in the article that humans have the "most dependent babies," and signaling behaviors are often repurposed responses, so it's a good starting point to say that crying (with big inhales and audible sobs) evolved as a "baby in distress" alarm, in which a baby makes a lot of noise because it needs help. We go to that place when we feel small or want the kind of support a parent would give.

Babies often don't have tears for the first few months, but I'm not sure that's important. I do think they play a role on the playground, and a lot of the speculation about their effects in social situations sounds right. I don't have any ideas to contribute on why crying is accompanied by tears.

In any other species, wearing a signal that advertises, "I recently lost in a dominance challenge," is a strict liability — an invitation for others to pile on, opportunistically, and attack you while you're down (or else to mentally note that you're no longer a good, strong ally). There's no upside, therefore, to using anything other than a quick facial expression or flash of body language, to show your submission only to the aggressor.

That sounds like an overly harsh picture of non-humans to me! I'm pretty sure at least certain apes help their potentially-non-kin in distress. Humans aren't the only social mammals.

I found the preamble a tad confusing. It seems to imply that all our evolutionary behaviours aim at solving a problem. I had understood that they are simply the emergent phenomenon of selection - in other words they are the behaviours associated with successful individuals/groups. Is this just a sort of shorthand - assigning a kind of design _intention_ to Nature as a simpler way of expressing this? If so, isn't it anyway the case that not all selected behaviours do actually solve a problem, but are sometimes just a case of "stuff that became associated with success"?

I should say my last encounter with biology was a GCSE some time in the 1990s.

> Is this just a sort of shorthand - assigning a kind of design _intention_ to Nature as a simpler way of expressing this?

Yes, and it's a fairly common, if misleading, shorthand. It's easy to communicate and so gets spread quickly and easily but it always takes careful reading to work out if the author is perpetuating a misconception around intelligent design or merely using an easily digestible metaphor. I suspect the author is doing the latter from a cursory reading, but I might be wrong.

You could describe it as bad language. Two physics examples.

A classic momentum problem where a moving railroad car "acts on" a stationary car making the cars couple and move together, slower. There's no ambiguity with language like "acts on". I'm sure a very angry physicist could get very unhappy about the finer details of "acts upon" in that context but mostly people are pretty tolerant of it.

But what, is acting on what, in a classic quantum mechanics double slit experiment? Is one slit acting on the other? I mean, you can't even define the wave/particle as a wave or a particle much less what the whatever it is, is acting on. A physicist sees it where a wave/particle is interacting with a system of slits sounds pretty suspect to a non-STEM person even if it is the weird truth. Or truthier than some other interpretations.

So given the two examples what does "acts on" mean in a physicist sense across all physics problems? Keeping in mind that the intelligent design people say things like "God acts on the earth via miracles" now how does that statement fit in with the two physics thought experiments on the topic of "acts on"?

Layman here. Wouldn't that metaphor be valid if the "problem" being solved is actually a driving factor of selection?

E.g., birds capable of flight have numerous physiological changes which could be seen as "optimizations" for flight. Yet, formally, "flight" doesn't appear anywere in the equation - it's just genetic markup that has been driven in a certain way by recombination and selection.

However, for many birds, the ability to fly - and to fly better than their predators or competitors in some aspect - actually highly influences the ability to survive: Therefore genetic markup that results in physiology more capable of flight results in a higher likelihood than markup that worsens the ability to fly.

(Of course other factors, such as environment, influence selection. Additionally, certain traits can increase likelihood of survival in a different way - even if they are poor solutions to the original "problem" - and lead to adaptation. So the metaphor is obviously not perfect)

The line is blurred here because it's describing human behavior, and we're certainly capable of intent. A little bit of it at a time, amortized over many generations and selected via evolution, but still intent.

Particularly blurred because of the Baldwin Effect: https://en.wikipedia.org/wiki/Baldwin_effect

The short short version is that once things have intention, they can evolve more rapidly in synch with that intention (Assuming that the intention also yields more viable offspring)

By "stuff that became associated with success", do you mean something like "the mutation that causes the occasionally life saving trait X also causes blue noses, and that's why our noses are now blue"?

I'm no gene expert, but I don't think it normally works that way. There are a lot more genes involved and a lot more degrees of freedom, making the nose color and X independent. Or so I, as a non expert, think.

Having recently read "Are We Smart Enough to Know How Smart Animals Are?" [1] by the brilliant primatologist Frans de Waal, the whole introductory paragraph reeks of the "humans only" dogma.

Even the link to the Wikipedia article directly contradicts the statement of humans being the only species to bury their dead.

How counter-intuitive it is: so many aspects of evolution we accept as continuum with shared phenotypes (and extended phenotypes) all the way through, yet when it comes to our intelligence and specialness, we forget all of this.

[1] http://books.wwnorton.com/books/Are-We-Smart-Enough-to-Know-...

FWIW the author acknowledges in a footnote that some of the "human only" traits are contested.

I totally agree that anthropocentrism in a fallacy/trap that we can fall into in all sorts of domains of thought - metaphysics, ethics, behavioral/evolutionary economics or whatever its called, etc.

But, to paraphrase Marshall Sahlins, "'Animals are basically people' is a much healthier perspective than 'People are basically animals.'"[1]. Which is to say, I think we can let our biases slide in this case, because even though we're focusing on ourselves because of our misperceived 'specialness', we can still learn broader truths in spite of this because we aren't actually so special or apart from nature.

[1] From intro to http://www.prickly-paradigm.com/titles/western-illusion-huma...

I hear what you are saying. But it is also a mistake to simply assume that there is nothing that is unique to human psychology. In particular, we need to explain why humans have been so remarkably successful, including at dominating other species.

For instance, in all other social mammals, as far as I know, the social group consists of only the group you directly belong to and are in immediate contact with, and this group is in competition with all other social groups of your species.

But in human foraging groups, you band is a member of a larger tribe of many bands that you cooperate with, even though the bands are in no immediate contact most of the time. Now think of all the behaviors and cognitive mechanisms required to make that happen.

Yeah, but I doubt that any non-anthropocentric measure of biological success puts humans anywhere special:

Biomass: krill dominate

Individual count: bacteria probably soon by a massive landslide

Evolutionary stability: the Goblin shark had been around for millions of years

When people talk about how special H. sapiens is they tend to always say that we're the only species to have some conjunctive list of traits. But for any given species there is some list of traits that single it out as unique and special, so I find those arguments pretty contrived.

However, perhaps humans do win out in the per capita production of waste heat category.

Wideness of niche.

Tardigraves and some lichens can live most anywhere it seems. And then life forms get more advanced and their range of terrain generally implodes in size, even migrating birds usually don't cover more than one continent at any given time.

Then suddenly despite being just another big ole thing you'd expect humans to be trapped in a dinky little African savannah by a river, but no, here we are under the ocean and covering the planet pole to pole and under ground and in the air and in space. If its not possible to live there we import stuff and live there anyway like Antarctica or space.

No species has a range as large as us, not even close, other than little microscopic tardigrave critters, and maybe rats. And our internal and external parasites I guess. You don't see alligators in the arctic or polar bears in jungles or whales in space stations or dolphins in grasslands.

There is one interesting bean counter type trait where you do something with the ratio of brain mass to body mass and add a correction factor for total mass, and we kick butt on that one.

Another one is information bandwidth, we can transmit a couple K visually per second via reading and a good fraction of a K per second via speech and no other animals even remotely come close. A human toddler transfers orders of magnitude more data before kindergarten than the entire lifespan of most animals, and as far as humans go toddlers rate as pretty dumb.

I'm sure if ants brains were not so small in an absolute sense and if they could communicate as many bits per second as humans can they'd be teaching us a thing or two about math and physics, but ...

Wideness of niche. That's a good one. Once we become trans-planetary, I guess that will also be quite a distinguishing trait. Also, note my optimism :P

Akin to the brain-to-body-mass ratio that you mention, I wonder if this wideness of niche idea can be meaingfully quantified.

Would you be able to point me to some sources? I'd like to level up a little bit on this topic.

Humans have caused far more extinctions than any other species. In a way you could consider that a sign of success/dominance. (Obviously most would instead view it as a tragedy. Regardless, it's a distinguishing factor.)

Neat summary and contextualization of the topic! Seems simple on the surface, which is why a nice lead through is helpful.

Last week at the zoo I watched the Chimpanzee dynamics for a good half hour or so. Very extreme by comparison to us. Loud. Chasing. Urination.

I suspect that biologically there's some overlap between Tears in Humans - which Chimps don't seem to possess the capacity to produce - and Defecation as a communication mechanism that Humans have spent a lot of time evolving away from. Each can be quite expressive.

Is there anyone here that's an actual subject matter expert on this topic? I know 1) that I am not a expert on why people cry 2) I don't believe the author has more than a day's worth of googling more background on the subject than me 3) I suspect there are people that have devoted a whole lot more time than the author to the question of why humans cry.

I'm not trying to judge the author, I'm just selfish about and hate wasting my time. This had every hallmark of half-assed pseudo-intellectualism and I don't have a day of time to find out.

>I don't believe the author has more than a day's worth of googling more background on the subject than me

There's a certain irony in this accusation considering 30 seconds on his site led me to find out he's writing a book on the subject of social psychology. http://elephantinthebrain.com. The fact that he took the time out of his book writing to write this article probably means he's researched and thought a lot about the subject.

He may be a secondary/tertiary source on this matter, but that doesn't mean he has nothing insightful to say about it, or that people who read the article are wasting their time (not to say that the reverse isn't true; maybe he hasn't properly learned the topic, but it's wrong to assume he just wrote this article off the cuff).

They also say:

> Incidentally, Why Only Humans Weep by Ad Vingerhoets is the most useful book I've read about crying.

strongly implying it's not the only reading they've been doing!

Ok, well, by way of that example, in less than an hour or so, I was able to read Vingerhoets last 2 years of selected publications (via his personal website, http://www.advingerhoets.com/journal-articles/) and of particular note one of the most recent (http://www.tandfonline.com/doi/full/10.1080/02699931.2016.11...) was actually rebutting/failing to reproduce the other study cited in this article by the Israeli group (http://faculty.washington.edu/beecher/Gelstein_et_al_2011.pd...) on the chemosignal theory.

It's not just about reading the sources. It the quality of the analysis and faithful representation of the sources. Don't you think that this major disagreement between two primary sources would have undermined his thesis (though captured the actual level of nuance/disagreement that exists in the research), or at signaled appropriate levels of uncertainty to the reader?

I still think a days worth of Googling (real, concerted, sustained effort) would leave anyone with a better understanding of the subject matter than reading this article. If someone wants to read an edgy pop-biology econometrical/anthrological opinion piece, that's another story.

"Like all psychology books, The Elephant in the Brain examines many quirks of human cognition. But this book also ventures where others fear to tread: into social critique. The authors show how hidden selfish motives lie at the very heart of venerated institutions like Art, Education, Charity, Medicine, Politics, and Religion.

Acknowledging these hidden motives has the potential to upend the usual political debates and cast fatal doubt on many polite fictions. You won't see yourself — or the world — the same after confronting the elephant in the brain."

Pardon my skepticism that someone that has a scholarly background in unrelated subject areas and has spent 10 years outside academia is going to do anything but scratch their own itch or vent their own spleen. Nothing wrong with that. But also pardon my false modesty. I'm not what I would consider an expert, but I'm not ignorant about biology, endocrinology, chemistry, evolution, genetics, psychology, history, geology, quantum mechanics, plumbing or any number of other subject areas that any person who wants to be well-rounded in has at their fingertips now.

Anyway, I didn't say (and don't think) the article was written off the cuff, I said it's half-assed pseudo-intellectualism. Fisking this thing is beyond by scope of my interest, but:

1. "If evolution devised to make our bodies do something, then the action is unlikely to be a meaningless side effect. There has to be a point to it." extraordinary claim, arguable merit, completely taken for granted

2. "Modern Western culture portrays sadness and tears as inextricably linked" I don't know anybody that thinks this (everyone is aware of happiness, response to beauty, stress, etc), one example of pattern of over- or misstating status quo to boost heterodox bona fides.

3. "There's an idea that we sometimes cry due to extreme happiness, but I think that's a little off the mark. I would rather say that we cry when we feel humbled by something great — something that would otherwise, if it weren't so humbling, cause unbridled happiness" the rare actual example of begging the question (in context of his later claims)

4. "Unfortunately, "stimulus: response" is the wrong frame to use to analyze crying, mostly because it saps the crier of any kind of intelligent agency." another extraordinary claim of arguable merit used to support later argument

5. "Another misconception is that crying is somehow directly therapeutic. Yes, it can feel good to cry, but no:" this whole line of reasoning is ridiculous, why bother to conduct double blind drug trials with placebos, again? Again, core to his thesis, and very flawed.

6. "The fact that we, as receivers, often feel manipulated by someone else's tears is the giveaway that crying is a signal — i.e., because it aims to change our behavior. When someone's tears are making a "request" that we feel is legitimate (and when our interests overlap with the sender's), we're happy to oblige. But we need to make sure we're not getting jerked around, so we're eager to evaluate the situation, to determine how appropriate an episode of crying is. In other words, we can get really judgmental about tears." I see no citation for this, and it doesn't match my experience, so I can only presume this is the author substituting anecdote/personal feelings for fact. Certainly under-supported.

7. "No one contests that these are, in fact, two of the ways we use tears. " I completely contest that human being utilize tears as signals in they way the author claims. It's only because of the rhetorical structure of the piece that this even seems plausible at this point. If I wrote a single sentence article that said "I believe crying is a signal to others of submission/distress instead of an involuntary reflex" the difference in a readers' reaction should indicate the difference between the degree this article is convincing vs the degree to which it has merit.

8. "Why did we evolve yet another way to signal submission or distress?" Arguable merit, lacking support for thesis this is evolved rather than learned.

9. "Tears, in this theory, are a political act, in the same way that tattling, gossiping, and whistleblowing are political" Did anyone even read to this point? How far are we removed from the practical reality of "I cried when I found out a loved one died" reality most of us experience?

10. "The answer is fairly simple. Humans, unique among all animals, have an instinct to resist aggression even when it's directed toward other members of the group (even non-kin)" Really, this could use a citation.

There are more, but again, my time is finite.

Please don't mistake my prior comment as "I didn't read the article". I read the article and thought it was lacking, an example of someone that starts out with their thesis and backfills with trivia, mediocre citation support, and fancy language to lead you to the intended destination. Since there are presumably actual experts on this out there, though, I was hoping that one of them might read this and volunteer some information about the subject.

This just seems like someone read Harari and took away the wrong lessons about pop soft-science writing.

>Humans, unique among all animals, have an instinct to resist aggression even when it's directed toward other members of the group (even non-kin).

I'm not convinced that this is a unique to humans.

The author is simplifying or possibly over-simplifying. About a third of The Secret of Our Success was devoted to how human social norms are different from those of our primate relatives and really the whole book is worth reading if you found the article interesting.

Can you provide some counterexamples?

After 5 minutes of googling:

* "Buffalo's brutal revenge: Animal gores lion and tosses it into the air after pride attacks its herd and slaughters one of its companions" http://www.dailymail.co.uk/news/article-3518658/Buffalo-s-br...

* "Rhinos save Buffalo from Hyena Attack" https://www.youtube.com/watch?v=e-cbxLyRN0o

I guess that wolves and crows will also be good examples, but I don't have a link just now.

Also, I live in Argentina and here it's common to have "dogs walkers" that pick a small number of unrelated dogs 5-10 from different owners. I guess that if someone is stupid enough to attack one of the dogs, the other dogs will react.

I've heard tell of ravens attacking humans who had previously attacked other ravens, sometimes quite a while before; at the moment I'm unable to go hunting a cite, but that might be a place to start.

I think it's clear from context that the author meant intra-group aggression. A dispute between a human and a group of ravens isn't really a matter of politics in the way a dispute within a group of humans (or chimps for that matter) is.

For some reason I just find his articles annoying..his tendency to ascribe a scientific or economic purpose/motive behind everything ..seems too much like positivism and eliminative materialism. Science and economics isn't the answer to everything.

Yeah the idea that these things can be explained simply by a purposeful guiding force like evolution is an attractive idea not unlike the belief in a higher power. What seems more likely is that many human traits and behaviors are highly complex evolutionary cruft — things accumulated over millions of years that fall into a few categories:

1) evolved "recently" to create a specific advantage for a human population (the author's favored explanation for crying)

2) provided an advantage for a distant ancestral species and stuck around long past the context in which they were advantageous (the human appendix)

3) random interaction between different traits or behaviors initially evolved from 1&2

4) random evolved trait that happened to be part of an evolutionarily successful population (Epicanthic fold)

5) random interaction between evolved traits or behaviors and a novel environment to produce novel behavior (over-eating and obesity caused by an evolutionary preference for high-caloric foods and their now-widespread availability)

I tend to not like the speculative aspects of evopsych like the ones in this post because they don't really account for the amount of randomness, complex interaction, and vestigial weirdness that seems to result from evolution.

I also find his articles annoying but I have no problem with ascribing a scientific or economic purpose/motive behind everything.

The problem is that the explanation has to be solid, based in evidence and experiments. This article is a well written rambling, or to be more clear just an opinion.

For example in:

> We're also the only creatures who sing from the ground, sing and dance together, bury our dead, point declaratively, enjoy spicy foods, blush, and faint [1] (not to mention all of our weird sexual practices).

> [1] human-unique traits. Some of these are contested. [...] And I'm sure there are other examples of similar behaviors enacted by non-human animals. But the basic point stands: We do a lot of things that, if not singularly unique, are nevertheless extremely rare.

He cherrypicks a few behaviors and say that they make us unique, and when there is contradicting evidence he just ignore it. Whales can sing, wolves howl (is that similar enough?) and just ignore birds because they are not intelligent enough. Bonobos have a lot of weird sexual practices that are similar to the human one, and other animals have even weirder sexual practices that are unimaginable in humans. And the list of exceptions go on ...

It's similar to: from https://xkcd.com/775/

> See, that's just the kind of bullshit sexism that discredits evo-psych. Your "evolutionary histories" always seem tuned to produce 1950's gender roles.

But perhaps they are useful for understanding and exploring how things work? As this article was clearly attempting to do.

I'm toying with the idea that tears are the direct result of excess CSF pressure (i.e. a way to vent that), having observed someone with that condition who tears very easily. Just maybe. This would presumably require that the lacrimal fossa be connected to the inside of the skull, which is certainly possible. Humans, the only upright animal, have unique fluid pressure problems within the skull (except for giraffes - maybe they cry, and nobody's noticed) so crying being unique to humans wouldn't be too surprising. One tiny bit of evidence, a study showing valproic acid ratios (in those taking the drug) are about the same in both CSF fluid and tears: https://www.ncbi.nlm.nih.gov/pubmed/6799283

Of course, crying being a signaling mechanism is another explanation. Maybe a better one.

The only other connection I can make is that migraines are closely correlated with dry eyes (and emotion can trigger migraines.) So people with migraines are sometimes advised to use eyedrops to reduce migraine incidence these days. Lacrimation is also a migraine symptom. If your brain is very active due to emotion, maybe tears help to reduce the chances that migraines result? (Or returning to the first hypothesis, maybe CSF pressure is elevated during migraines.)

Not a disproof, but chimps are more socially sacrificing than this article indicates, they will find crippled chimps for long periods, as a group; IIRC not just relatives.

"I'm toying with the idea that tears are the direct result of excess CSF pressure (i.e. a way to vent that)," Don't, it's not. Why don't you thing 1) high CSF pressure is mood altering/predisposing to tear activity 2) high CSF may be the result of an underlying cause also express in lactrimal gland activity? Those are simpler explanations, and not false, like the lacrimal duct/CSF hypothesis. As for valproic acid, you are letting the tail wag the dog (the point of the article was to suggest diagnostic technique, and the drug was present in all tested fluids... the burden of proof would be on your to say why concentration in tears would not correlate well with serum levels, which also correlated as well with csf levels).

The only things I could find about migraines and dry eyes were positively correlated, but not strong, and not enough to be causative. Can you share more sources? Also, most source indicates IIH can be comorbid with migraines, but is unrelated, curious if you have sources to share on that, too.

I do think "high CSF pressure is mood altering/predisposing to tear activity" precisely because the CSF pressure needs to be brought down" (in this hypothesis.) and that high CSF is the result of an underlying cause that also expresses itself in lactrimal gland activity, due to said pressure. I think you'd have to do an arabesque to find an underlying cause with two roots from some underlying cause rather than one (obviously more complex even if you can think up such a thing) (and it wouldn't explain the study I cited.) But knock yourself out, suggest such a causal arrangement/pathway.

The I believe very recent study I saw found a high correlation. I've heard anecdotal reports of eyedrops helping; it's too soon to find studies of (neutral) eyedrops helping, but you can find preliminary studies of migraine treatment beta blocker eyedrops at pubmed dot com.

No tail wagging dog - it's common for studies about one thing to discover something interesting that's consistent with quite another hypothesis (which is the most evidence can be, qua Popper.) That's all I've claimed in this case. There was no such correlation with saliva, so it's clear that disproof was risked - the Popperian litmus test for actual evidence.

How does this theory explain the act of crying in private?

The theory explains why someone would want not to cry in front of people (loss of prestige/dominance), but not why someone would want to cry alone, in private.

The theory is that we involuntarily cry under certain conditions, to leave physical evidence of those conditions later.

So one answer to your question is that you never know if someone will come by and look at your face in a few minutes.

Why do we laugh or smile in private when we're watching something funny? Why do we say "Ow!" when we're hurt, or scream when we're startled? Why does our body posture change based on our mood, even when no one's around to watch?

Adding in an extra check that says "if (someone is watching) { ... do this signaling thing ... }" more costly than just doing it.

That's not how evolution works. If evolution builds a mechanism to make you respond to a certain stimulus in a certain way, then it's more work (and more unlikely) to then make that mechanism only act under certain circumstances. We wouldn't not cry in private unless there were additional fitness advantage to it.

The appendix seems to be a counterexample to this philosophy of evolution. Useless body parts exist. What are the chances there are no useless behaviors? (By "useless" I mean "no fitness advantage.")

Not sure I agree wholly with the GP, but recent theories suggest that the appendix does in fact serve a useful purpose. It can act as a reservoir for gut bacteria that are necessary to our digestive health. It helps repopulate gut flora when they get wiped out by illness (often caused by other bacteria) that causes a bad case of the runs.

I agree that science can't explain everything. But I think that for every individual case, you need to make a sincere attempt to come up with a scientific explanation and then fail, before you can decide it is a mystery.

Our expression of grief is probably a result of a mutation that altered the structure of our amygdala so that fear controls brain chemistry less than our primate ancestor. When an animal is in fear, chemical reactions desensitize and suppress brain activity involved in emotional expression to protect the self from being perceived as weak and dedicate brain energy to motor functions.

Looking at tears and the neurological development from genetics through adulthood would be a great way to understand what makes us human.


It seems to me that crying often produces a cognitive process. So I feel sad about something and feel I can't do anything about it and cry, and after a while I don't feel so sad and see the situation in a different perspective where I can go on living. Or something distressing happens, and I talk about it and cry some, and after a while I feel better.

This seems to be a different sort of situation than crying to get help with an immediate situation. I wonder if that sort of case evolved first, and then got modified and used for the cognitive processing one.

I have a two year old son. As you can imagine he cries a lot. Lately we have been applying some EQ lessons we've learned and have tried to teach him to be aware of how he feels when he cries. You'd be surprised he's actually pretty good.

He starts to cry and then says "I'm crying." We acknowledge that he is crying by saying something like "You seem sad." He generally stops crying at that point and we move on. Its like the signal was sent and received. He feels heard.

Interesting article, still a lot of unanswered questions and open areas for discussion...

Most of my life, I was pretty unemotional. I didn't cry watching movies or TV, and even personal matters never brought me to tears. At some point, just shy of 30 years old, everything changed. I was always empathetic, but, that went in to overdrive... Seeing someone else cry or watching a powerful moment on TV can trigger an instant welling of emotion.

I recall Scott Alexander (slatestarcodex.com) proposing the tears/bullying hypothesis somewhere, but I can't seem to find it at the moment.

The subject matter reminded me a lot of his post about guilt, but I don't remember one about tears. Maybe that's what you were thinking of?

Could tears be there for some kind of moderating effect on cellular action potentials? Tears are notoriously salty; "salty" has even become synonymous with bitterness, angst, or remorse. I think their production does seem to have a noticeable effect on cognition, but for all I know it's just a coincidence. Certainly they would extract sodium from the body to some degree, I just wonder how much of an effect that would have.

EDIT: here is a vaguely-relevant(?) study from 2014 about an infant presenting with inconsolable crying allegedly because of "an alteration of sodium channels inducing neuropathy in small-caliber fibers" (1)

EDIT 2: As for why this is something that happens from the eyes specifically, I wonder if it is for a particular local effect on ion channels in the frontal lobes.

[1] https://www.ncbi.nlm.nih.gov/pubmed/24468061

First: tears are just as "salty" as blood, so they have no net effect (120–170 mmol/l sodium for tears vs 140 mmol/l in plasma). Even if that was not the case, it would have hardly any effect (5 liters of blood v. a few ml tears). Finally, any effect would be dwarfed by the robust homeostatic system regulated by the hypothalamus.

Second: from your study: "Treatment with analgesics and ice packs was established" the infant was crying because the peripheral vascular disease caused them substantial pain.

Edit: I guess your "edit 2" is aimed at me? I mean, maybe? It seems like a huge piece of speculation on your part without a particularly well thought out mechanism, so I'd love to see a bit more work on your part before discussing further. I assume you mean that it would be a change in Na+ concentrations propagated by osmotic difference via the optic nerve, because otherwise I don't know how you'd propose that would work (meninges, blood-brain-barrier, and all). Some kind of quantification of the osmotic difference and the rate that would propagate..

I am not clear on what you mean by "no net effect", and not entirely sure how tears are comparable with blood since tears are expelled from the body; blood (and any sodium it carries away from the brain) hopefully remains in the body (not to mention that blood contains a lot more than just NaCl, compared with tears). I am also curious as to how quickly the hypothalamus would respond to a local drop in sodium ions. What you say is plausible; I do tend to agree with you about the study interpretation. Like you, I really want to hear from an expert in this field.

EDIT to reply to your edit: No, my edit 2 above was made before I saw any replies, sorry about that. Yes, it is certainly nothing but speculation.

(Thank you for pointing me in the direction of further study - I'm afraid this type of thing is a bit beyond my education when it comes to biology)

"No net effect" = tears are produced by the lacrimal glad. I am more of an interested hack, compared to someone that actually knows something (medical professional like a neurologist or ophthalmologist), but my educated guess is that cells in the lacrimal gland produce tears entirely from inputs from the circulatory system, and because of the circulatory system structure in your brain v. face, it's actually rather not as local as the physiological proximity suggests. So the change would be indirect, mediated by blood, and since the concentration of sodium is the same in each crying wouldn't effect blood sodium concentration in the first place. You may under-appreciate how rapid blood moves through the body, too, and quickly any local change would move to equilibrium.

ps: you're welcome, happy studying! (it's daunting, keep in mind https://news.ycombinator.com/item?id=1390027, and remember that some of the smartest people out there become doctors, and they spend a dozen+ years training in just single areas of study and indefinite continuing education)

There seems to be a very interesting book in the making by the same author and in a similar vein of this article. The website says it will be finished at the beginning of 2018:


Curious if anyone knows anything about the similarities/differences between human crying and dog whining?

Or birds holding a wake for a lost member of the flock. California Quail do that around me. One will get caught by a cat, and next day you will see the flock, right where the other bird died.

I remember having a debate in high school about this. There was a very obvious difference between people that grew up on farms around lots of animals, and types of animals, and everyone else (most of which lived in town). Farm kids: yes, animals have emotions and "feel". Town kids: very uncertain. Later I went to a larger city for college in a state not known for agriculture, it amazed me the ignorance of people about animals. Absolutely no clue. And the larger the city I visit, the less people comprehend the outside world.

Do dogs whine amongst themselves, or is it a behavior they only use around humans? (like meowing in cats: cats don't meow to other, only to get something from people - it's a trait learned from domestication). I image behaviors learned by domestication behave a little differently: the selection pressure is much greater, and they evolve in response to feedback from a completely different species instead of one's own.

Kittens meow (and loudly) to their mothers if left alone for too long. So it's not a behaviour unique to human cat interactions.

As is typical, it is a innate behaviour that seems to be repurposed when interacting with humans.

Humans are very auditory, and cats faces are not as expressive as dogs are. So cats seems to [1] discover that meowing is a good way to get a human's attention.

Behaviourism predicts that when an organism is faced with a 'problem' to solve it will often run through it's behavioural repertoire, trying each behaviour until one seems to trigger the desired outcome.

[1] each cat on his own!

There is also another cat sound that to me seems to signal surprise, that sort of 'mrrrrow' sound.

If you wake up a cat, or sneak up on it they consistently make that sound.

Actually, with meowing, adult cats not raised around humans don't do it, but kittens do it; it's a behavior of kittens that continues being rewarded in domestic situations after maturity and so isn't abandoned.

Neotenous behavior isn't at all unusual in domesticated animals.

That's actually a great question. I'm not sure at all. It's definitely really hard to look at a dog's ability to communicate in a vacuum outside human domestication.

Couldn't find any papers on whether they whine amongst each other on a quick Google myself.

In the case of dogs, we should probably look at wolves to see if the whining was a response to domestication. But I don't know if wolves whine, so I'm not much help there.

>Idk if wolves whine

They do

Domestication goes both ways, over time we may have developed a response to them whining.

I remember a test done where humans had to listen to dog and cat sounds and identify what the animal was communicating (to humans or other animals) and we were quite good at it.

Are you sure about the meowing? I have heard and seen cats meowing at magpies and to each other.

Cats will chirp at birds, but it's a hunting behavior and a different sort of sound. I've never seen adult cats meow at one another the way they will at humans.

Definitely queues up Terminator 2: https://www.youtube.com/watch?v=eSotD5M3bsY

A bit of an odd article. I normally equate crying as grieving, viz a combined physical and psychological reaction to some external distress. Here it seems the author is fundamentally concerned with crying as the purely physical response of 'tearing' which I don't know if it really makes sense to breakdown that way. Nonetheless, an interesting piece and written by a fellow Cal Bear as well.

Most of the things in this list are not specific to humans.

Interesting idea + bad research = fake news

this needs to stop so badly.

I hope someday I'll read such detail research on when and how we evolve to lie. It always fascinated me, when this starts and how it propagates from one generation to another. I'm almost sure, it's the most unique human trait.

Read "Liars and Outliers" by Bruce Schneier.

Is he sure that only humans cry? I can perfectly remember my dog (RIP) crying with tears when I lock him up in a cage (sometimes we need to lock him up because he is too friendly to visitors).

I don't know about the author, but every vet that I've talked to has seemed pretty certain of it. We have an older dog who has begun to get weepy. We first assumed that it was related to resultant pain from her arthritis, but her vet (and three subsequent vets) all assured me that I was definitely wrong.


Is it possible that there's an allergen in or near your dog's cage?

He just doesn't have tears, he cries out loud and make a sound like he is in pain.

I believe the howling. Dogs definitely howl, and will happily do so to voice disapproval, sadness, etc., etc. If there are tears alongside that howling, then your dog may be an anomaly.

Article is wrong. Crying is cathartic.

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