Look me in the eye

It's fascinating how much information can transfer between two humans solely through eye contact.

I say that as a person who has a serious issue with doing this at all.  I have no idea where my avoidant behavior comes from, although I do recall hearing "Look at me when I'm talking to you!" a lot as a kid when I was in trouble.  But I find making sustained eye contact dreadfully uncomfortable.  I recall vividly being in a men's workshop a while back where one of the exercises was standing, a foot or so apart, face-to-face with another man, and simply holding each other's gazes for three minutes.  Those three minutes seemed to drag on forever, and it required phenomenal willpower on my part not to look away.

[Image is in the Public Domain]

Perhaps part of it is my intense dislike of being the focus of attention, another outcome of my rather unfortunate childhood.  Interestingly, this tendency never bothered me much while I was teaching; to me, a teacher isn't (or shouldn't be) saying "Hey, look at me!", (s)he is saying about the topic being studied, "Hey, let's look at this other thing together, isn't this cool?"

I've wondered, though, if my tendency to look away when people glance at me has influenced my ability to form relationships.  I can see how this might make me seem aloof or unfriendly.  It's certainly contributed to a regrettable inability on my part to be able to tell when someone is flirting with me.  My friends, knowing my general cluelessness, have been known to say, "Um... you do realize (s)he was flirting with you, right?"  The answer almost always is "no."  The sad truth is that I wouldn't know if someone was flirting with me unless they were holding up a sign that said, "HEY.  STUPID.  I AM CURRENTLY FLIRTING WITH YOU."

And given the fact that I would probably be looking away the whole time, even that might not help.

The reason all this squirm-inducing stuff comes up is because of a study out of the University of Würzburg published this week in the Journal of Experimental Psychology, entitled, "Don't Look At Me Like That: Integration of Gaze Direction and Facial Expression," in which we find out that for most people, whether or not we have a desire to meet someone's eyes depends strongly on what their facial expression is.

The researchers, led by Christina Breil, used photos of individuals who were either looking toward or away from the viewer, and had one of four emotional expressions: joy, anger, disgust, and fear.  The team measured how quickly volunteers looked into the eyes of the person in the photograph, and how long that (virtual) eye contact was maintained.  What they found was that we tend to look more quickly into the eyes of people expressing joy or anger (and hold the gaze longer), and be reluctant to look at those expressing disgust or fear.  In fact, the disgust and fear photos attracted more attention when the person in the photo was looking away from the viewer.

The anger results interested me the most, because I get really uncomfortable (even more uncomfortable than normal, which is saying something) around angry people.  I'm a champion conflict-avoider, which probably won't come as any real shock.  Breil et al. explain that this is thought to occur because anger, while generally considered unpleasant, is still an "approach-oriented" emotion; note that we even call angry confrontations "getting in your face."  Disgust and fear, on the other hand, are "avoidance-oriented;" they make us want to retreat from whatever it was that elicited the response.

I wonder how someone with a generally avoidant orientation, like myself, would have done with this experiment.  I certainly don't have nearly the problem looking at a photograph that I do looking into the eyes of a real person.  But if I hadn't known what the gist of the experiment was beforehand (which the volunteers, of course, didn't), it'd have been interesting to see how I'd have reacted.

The eyes, they say, are the window to the soul.  Certainly we express a great deal of feeling with them.  And how we respond to those expressions seems to be pretty nearly universal -- illustrating that once again, for social animals, effective communication is a strong driver for evolution.

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Puppy dog eyes

We have two dogs, our big thirty-kilogram galumphing galoot, Guinness:

And his comical sidekick, little eight-kilogram Cleo:

They are best buddies and love to be outside playing together, which is as fun for us as it is for them because watching them is so damn comical.  Cleo is about twice as fast as Guinness is, and runs in circles around him, sometimes attempting a full-on body slam that is completely unsuccessful because of this inconvenient law of physics called Conservation of Momentum.  Usually Cleo just ricochets off Guinness's side like a ping-pong ball off a boulder, but it never seems to discourage her from trying again.

Remember Chester and Spike, from Looney Tunes?

Yeah, that's Guinness and Cleo, right there.

Carol and I frequently laugh ruefully at how many times a day we say, "They are so stinkin' cute."  I mean, it's true, but it's kind of ridiculous how much they have us wrapped around their paws.  Guinness, especially, has an incredibly expressive face, and when we talk to him he gazes up at us adoringly as if he's hanging on every word we say.  The funny thing is that it doesn't, in fact, matter what exactly it is we're saying.  We could be explaining to him something like why it is not a good idea to eat the sofa, or reading to him from a text on economics for that matter, and he will still stare at us as if to say, "My god, yes!  That's genius!  I never would have thought of that!"

A paper presented last week at the annual meeting of the American Association for Anatomy has shown that this ability dogs have to communicate with their facial expressions is no accident.  Researchers Anne Burrows and Kailey Omstead of Duquesne University did a detailed comparison of mimetic muscles -- the tiny muscles in the face that allows us (and other animals) to alter our expressions -- between domestic dogs and wolves, and they found something fascinating.

To understand what's going on here you have to know a little about muscle composition.  In the broadest-brush terms, mammals have two types of skeletal muscles; fast-twitch muscles, which can contract rapidly and powerfully but aren't able to maintain sustained contraction, and slow-twitch muscles, which are much slower to react but can remain contracted for long periods.  Our upper bodies are predominantly fast-twitch muscle; this is why lifting a heavy weight with your arms is doable, but keeping it lifted for more than a few minutes is excruciatingly difficult.  On the other hand, the three big muscle groups in your upper legs -- the quadriceps, biceps femoris (hamstrings), and gluteus maximus -- have to maintain tension just to allow you to support your own body weight, but can do so for hours without fatiguing.  One of the reasons for this is that slow-twitch muscles have a protein called myoglobin, which improves the ability of the muscle to absorb oxygen from the blood; it's this protein that makes the dark meat of a chicken dark.  And notice which two muscles are dark meat -- the leg and the thigh, same as us.

Not that I'm recommending eating humans, mind you.

Anyhow, back to dogs.  The analysis by Burrows and Omstead found a striking difference in the muscle composition of dogs' faces as compared to wild wolves; dogs' mimetic muscles are predominantly fast-twitch, while wolves' are predominantly slow-twitch.  What this means is that dogs' faces are much quicker to change in expression.  Wolves do have expressions; one obvious example is the wrinkled forehead and retracted lip that signifies aggression or anger.  But domestic dogs can alter their expressions rapidly and subtly in response to the circumstances, allowing them to communicate with humans in a way few other animals can.

"Dogs are unique from other mammals in their reciprocated bond with humans which can be demonstrated though mutual gaze, something we do not observe between humans and other domesticated mammals such as horses or cats," said study co-author Anne Burrows.  "Our preliminary findings provide a deeper understanding of the role facial expressions play in dog-human interactions and communication."

This difference between dogs and their wolf cousins is almost certainly due to unwitting artificial selection by humans -- our ancestors back in the Paleolithic, when we have the first evidence of dog/human cohabitation, selected the puppies that were the most responsive to us as companions.  (At the same time, selection was going on for other features as well, such as size, color, and skill at tasks like herding or retrieving.)  Over the intervening years this selection has actually altered the composition of the muscles in our canine friends' faces, so that they're even better at communicating with us.

Which I think is amazingly cool.  But I'd better wrap this up, because Guinness just looked at me with a furrowed brow and a head tilt, which means he wants his breakfast.  You know how it goes.

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Falling into the uncanny valley

As we get closer and closer to something that is unequivocally an artificial intelligence, engineers have tackled another aspect of this; how do you create something that not only acts (and interacts) intelligently, but looks human?

It's a harder question than it appears at first.  We're all familiar with depictions of robots from movies and television -- from ones that made no real attempt to mimic the human face in anything more than the most superficial features (such as the robots in I, Robot and the droids in Star Wars) to ones where the producers effectively cheated by having actual human actors simply try to act robotic (the most famous, and in my opinion the best, was Commander Data in Star Trek: The Next Generation).  The problem is, we are so attuned to the movement of faces that we can be thrown off, even repulsed, by something so minor that we can't quite put our finger on what exactly is wrong.

This phenomenon was noted a long time ago -- first back in 1970, when roboticist Masahiro Mori coined the name "uncanny valley" to describe the phenomenon.  His contention, which has been borne out by research, is that we generally do not have a strong negative reaction to clearly non-human faces (such as teddy bears, the animated characters in most kids' cartoons, and the aforementioned non-human-looking robots).  But as you get closer to accurately representing a human face, something fascinating happens.  We suddenly start being repelled -- the sense is that the face looks human, but there's something "off."  This has been a problem not only in robotics but in CGI; in fact, one of the first and best-known cases of an accidental descent into the uncanny valley was the train conductor in the CGI movie The Polar Express, where a character who was supposed to be friendly and sympathetic ended up scaring the shit out of the kids for no very obvious reason.

As I noted earlier, the difficulty is that we evolved to extract a huge amount of information from extremely subtle movements of the human face.  Think of what can be communicated by tiny gestures like a slight lift of a eyebrow or the momentary quirking upward of the corner of the mouth.  Mimicking that well enough to look authentic has turned out to be as challenging as the complementary problem of creating AI that can act human in other ways, such as conversation, responses to questions, and the incorporation of emotion, layers of meaning, and humor.

The latest attempt to create a face with human expressivity comes out of Columbia University, and was the subject of a paper in arXiv this week called "Smile Like You Mean It: Animatronic Robotic Face with Learned Models," by Boyuan Chen, Yuhang Hu, Lianfeng Li, Sara Cummings, and Hod Lipson.  They call their robot EVA:

The authors write:

Ability to generate intelligent and generalizable facial expressions is essential for building human-like social robots.  At present, progress in this field is hindered by the fact that each facial expression needs to be programmed by humans.  In order to adapt robot behavior in real time to different situations that arise when interacting with human subjects, robots need to be able to train themselves without requiring human labels, as well as make fast action decisions and generalize the acquired knowledge to diverse and new contexts.  We addressed this challenge by designing a physical animatronic robotic face with soft skin and by developing a vision-based self-supervised learning framework for facial mimicry.  Our algorithm does not require any knowledge of the robot's kinematic model, camera calibration or predefined expression set.  By decomposing the learning process into a generative model and an inverse model, our framework can be trained using a single motor dataset.

Now, let me say up front that I'm extremely impressed by the skill of the roboticists who tackled this project, and I can't even begin to understand how they managed it.  But the result falls, in my opinion, into the deepest part of the uncanny valley.  Take a look:

The tiny motors that control the movement of EVA's face are amazingly sophisticated, but the expressions they generate are just... off.  It's not the blue skin, for what it's worth.  It's something about the look in the eyes and the rest of the face being mismatched or out-of-sync.  As a result, EVA doesn't appear friendly to me.

To me, EVA looks like she's plotting something, like possibly the subjugation of humanity.

So as amazing as it is that we now have a robot who can mimic human expressions without those expressions being pre-programmed, we have a long way to go before we'll see an authentically human-looking artificial face.  It's a bit of a different angle on the Turing test, isn't it?  But instead of the interactions having to fool a human judge, here the appearance has to fool one.

And I wonder if that, in the long haul, might turn out to be even harder to do.

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Saber-toothed tigers.  Giant ground sloths.  Mastodons and woolly mammoths.  Enormous birds like the elephant bird and the moa.  North American camels, hippos, and rhinos.  Glyptodons, an armadillo relative as big as a Volkswagen Beetle with an enormous spiked club on the end of their tail.

What do they all have in common?  Besides being huge and cool?

They all went extinct, and all around the same time -- around 14,000 years ago.  Remnant populations persisted a while longer in some cases (there was a small herd of woolly mammoths on Wrangel Island in the Aleutians only four thousand years ago, for example), but these animals went from being the major fauna of North America, South America, Eurasia, and Australia to being completely gone in an astonishingly short time.

What caused their demise?

This week's Skeptophilia book of the week is The End of the Megafauna: The Fate of the World's Hugest, Fiercest, and Strangest Animals, by Ross MacPhee, which considers the question, and looks at various scenarios -- human overhunting, introduced disease, climatic shifts, catastrophes like meteor strikes or nearby supernova explosions.  Seeing how fast things can change is sobering, especially given that we are currently in the Sixth Great Extinction -- a recent paper said that current extinction rates are about the same as they were during the height of the Cretaceous-Tertiary Extinction 66 million years ago, which wiped out all the non-avian dinosaurs and a great many other species at the same time.  

Along the way we get to see beautiful depictions of these bizarre animals by artist Peter Schouten, giving us a glimpse of what this continent's wildlife would have looked like only fifteen thousand years ago.  It's a fascinating glimpse into a lost world, and an object lesson to the people currently creating our global environmental policy -- we're no more immune to the consequences of environmental devastation as the ground sloths and glyptodons were.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!] 

Canine emotional therapy

I had a rather terrifying nightmare last night, and as is usual with such things, the retelling doesn't convey how absolutely awful it was.

My wife and I were in a house -- not our own, it was one of those generic tasteful split-level homes you can see in every upper-middle-class suburban neighborhood in the United States.  From the furnishings it was occupied, and the owners obviously had children because there were toys scattered about.

Then the toys began to come to life.

It wasn't like Chucky in Child's Play, where it was a possessed doll that had an evil personality; it was more that they were being controlled remotely, and only looked like toys but were actually weapons.  After a struggle we fought our way past them, and at some point (don't recall how) we were able to deactivate them.  So we're trying to find the way out of the house, stepping over all the fallen toy/weapons, and then (of course) they started to reboot.

This was the moment when I was thrashing around so much that my wife woke me up.  I didn't scream or anything (that'll be relevant in a moment) but was flailing and had awakened her.  She reassured me that it was just a dream, we didn't have evil remote-controlled toys in our room, and I was able to shake the fear pretty quickly.

I got up to get a glass of water, and when I opened my bedroom door, my dog, Guinness, was standing there looking up at me with a concerned expression.

So I got my water, and he followed me back into the bedroom, jumped on the bed, and basically smooshed himself against me, his head under my chin.  I put my arm around him and he gave a big sigh and we both fell back asleep.

Why this is weird is that this was pretty un-Guinness-like behavior.  He's never allowed on our bed at night, mostly because he weighs seventy pounds and takes up a large amount of space.  We sleep with the door closed and he always spends the night quietly snoozing on his sofa.  (Yes, he has his own personal sofa.  Yes, I know he's ridiculously spoiled.)  Whenever I get up in the middle of the night -- not that unusual, because I'm an insomniac -- he virtually never budges, much less barging in and jumping in bed with me at two AM.  

So his behavior last night was very uncharacteristic, up to and including his basically draping himself over me once we got back into bed.  I know it may sound ridiculous, especially coming from a self-proclaimed rationalist skeptic -- but I swear, it seemed very much like he sensed that I'd had a bad scare and was upset, and wanted to comfort me.

Me with my valiant protector

What makes me curious, of course, is how he knew.  As I said, I hadn't shouted out.  The conversation my wife and I had after I woke up was quiet, and given that I recovered from my fright rather quickly, not at all agitated.  And when I got up to get my glass of water, he was already at the door waiting for me, so he must have known something was wrong, enough that it woke him up, and he decided to come and see if he could help.

Any dog owner will confirm that dogs are uniquely in tune with their owners' emotional states.  We had a brilliant, and rather loony, border collie named Doolin, who could sense when my wife was going to have a migraine and would essentially glue herself to Carol's side until it was over.  The odd thing was that Doolin knew before Carol did; in fact, Carol came to look at Doolin's odd behavior as a clue that she better find her migraine meds while she could still think straight and see what she was doing.  Another of our dogs, Grendel, always knew when we'd finished dinner.  We have a strict no-begging policy at meals, but once we're done, even if we're still seated at the table, they can come up for some petting and attention.  Grendel could infallibly tell when we were done eating, and seconds later would come loping in to get an ear rub.  We tried more than once to figure out what his cue was -- whether it was the sound of putting our silverware or glasses down, or something we said like, "That was good, thanks for cooking" -- but never could really pin it down.  But his appearance was like clockwork, every single night.

There have been some preliminary studies of dogs' abilities to recognize their owners' emotions from facial cues, with (in my mind) rather equivocal results.  One back in 2016, which appeared in Biology Letters of the Royal Society, looked at "equivalent valence" between a human's expression and the emotion conveyed in a recorded utterance -- how, for example, a dog might react to an angry face combined with a playfully-toned phrase.  It found that when the facial expression and the tone of the utterance had equivalent valence, the dog spent longer looking at the photograph than either when the valence was different, or when the photograph was shown with a recording of white noise.

A second, in 2018, looked at the difference in reaction when dogs were shown faces with various emotions simultaneously on two different monitors, one to the dogs' right, the other to the left.  It's been determined that dogs, like humans, have lateralized brains, with the two cerebral hemispheres performing complementary (rather than redundant) functions, and that (again like humans) they usually have dominant left hemispheres.  Because of this, the conjecture was that more intense emotions would cause the animals to pay more attention and turn their heads to the left, while less intense emotions would either show no preference or result in a rightward turn.

Sure enough, that's what happened.  Human faces showing fear, anger, and disgust caused a preferential leftward turn; a surprised face and a neutral expression caused a rightward turn (and also a shorter time looking at the photograph).  Additionally, the intense/negative faces caused the dogs to experience an increase in heart rate and signs of canine stress -- lowered tail, pulled back ears, and so on.  A surprising result was that a happy face caused a leftward turn.  One possibility is that humans' smiles are a fairly uncommon way of expressing relaxation and happiness in the animal world; for most species, baring the teeth is a threat, not a gesture of friendship.  It's also possible that the dog was reacting because of the intensity of the expression, not its actual emotional content.  Impossible to tell.

Those experiments, though, are pretty broad-brush.  What I've found in my long years of being a dog owner is how attuned they are to the specific gestures and actions of their owners, when the same gesture or action from someone else would cause no response at all.  Our aforementioned border collie, Doolin, was a phenomenal frisbee-catcher -- but only when my wife was throwing it.  When Carol threw the frisbee, Doolin always took off in exactly the right direction, and nailed maybe 95% of the throws with a spectacular leaping catch in mid-air.  With me, she was equally likely to run pretty much any direction, and missed most of the throws.  Like with Grendel's "dinner's over" cues, we tried like hell to figure out what Doolin was picking up about my wife's body language when she threw the frisbee that I couldn't seem to duplicate, and never did figure it out.

So I'm back to where I started, which is simply an anecdotal sense that dogs are exquisitely sensitive to their owners' emotional states.  I've noted that when I'm feeling low Guinness is much more likely to spend the day snoozing at my feet rather than on His Personal Sofa, but I don't know whether that's because of his sensitivity, because of dart-thrower's bias, or simply my reading more into his behavior than what's actually there.  In any case, it's a curious phenomenon, and worthy of more study.  In the interim, I'd love to hear my readers' dog stories -- feel free to post your experiences of your dogs picking up on your feelings in the comments section.  Or, conversely, feel free to tell me I'm full of malarkey.  Don't worry, it won't bother me, Guinness will be right there to make me feel better.

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Science writer Elizabeth Kolbert established her reputation as a cutting-edge observer of the human global impact in her wonderful book The Sixth Extinction (which was a Skeptophilia Book of the Week a while back).  This week's book recommendation is her latest, which looks forward to where humanity might be going.

Under a White Sky: The Nature of the Future is an analysis of what Kolbert calls "our ten-thousand-year-long exercise in defying nature," something that immediately made me think of another book I've recommended -- the amazing The Control of Nature by John McPhee, the message of which was generally "when humans pit themselves against nature, nature always wins."  Kolbert takes a more nuanced view, and considers some of the efforts scientists are making to reverse the damage we've done, from conservation of severely endangered species to dealing with anthropogenic climate change.

It's a book that's always engaging and occasionally alarming, but overall, deeply optimistic about humanity's potential for making good choices.  Whether we turn that potential into reality is largely a function of educating ourselves regarding the precarious position into which we've placed ourselves -- and Kolbert's latest book is an excellent place to start.

[Note: if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Why the sad face?

Springboarding off Saturday's post about non-human animals having emotions, today we're going to look at a study that came out a couple of weeks ago in Frontiers of Veterinary Science that demonstrates that not only do animals have emotions, they've evolved to be able to play on ours.

In a paper with the rather intimidating title "The Application of Geometric Morphometrics to Explore Potential Impacts of Anthropocentric Selection on Animals' Ability to Communicate via the Face: The Domestic Cat as a Case Study," animal behaviorists Lauren Finka and Mark Farnsworth (of Nottingham Trent University), Stelio Luna (of São Paulo State University), and Daniel Mills (of the University of Lincoln) looked at an interesting phenomenon; the way human selection of animals for pets has led to the animals evolving traits that trigger a nurturing response in the owners.  A particularly interesting one is the "inner eyebrow raising muscle," which in domestic dog breeds is far more highly developed than in wild dogs, and which causes the furrowed brow "sad puppy" look any dog owners out there will no doubt recognize immediately.  My lovable rescue dog Grendel was the past master of this particular expression:

No, he was not spoiled.  Don't even suggest such a thing.

People seeing Grendel usually took one look at him and said, "Oh, you poor poor puppy!  Why the sad face?  Here, puppy, have a cookie."  Which, of course, led him to understand that looking sad got him what he wanted.

Evolution for the win.

The study that came out a couple of weeks ago, however, took a look at cats, which in general have less emotionally expressive faces than dogs do.  My wife's cat, Geronimo, who died a couple of years ago at age eighteen, had a spectrum of facial expressions that ran the gamut from "I'm pissed off" to "I hate you," occasionally reaching the level of "fuck off and die."  I know this is ascribing human thoughts to a non-human animal, but whenever Geronimo looked at me, his yellow eyes narrowed to slits, I always came away with the expression that he was plotting to disembowel me in my sleep.

But the current study shows that most domestic cats have a wider range of emotional communication than Geronimo did.  Interestingly, what the researchers called "pain features" -- movements of the face indicative of distress -- were often present in "baby-faced" breeds like Persians even when the animals were not actually in distress, while long-faced breeds like Siamese showed fewer "pain features" even when the animal was in pain.  I wonder if this is why Siamese cats have a reputation for being "aloof" and "independent," and Persians a reputation for being in need of pampering?

The authors write:

The ability of companion animals to readily solicit care from humans is obviously advantageous.  However, it is possible that permanently vulnerable looking individuals might have a diminished capacity to clearly indicate when care is or is not required, as well as to display other information relevant to their actual state or intentions.  Thus, if certain cat breeds are being selected to display “pain-like” features on their faces, these features may serve to solicit unwanted or inadequate attention from their caregivers.  More generally, such types of anthropocentric selection might lead to increased anthropomorphic tendencies.  If, for example, the animal has the appearance of an expression which humans find relatable on some level, even if it is not necessarily reflective of that animals' affective state, it may be used to attribute emotions or characteristics to them.  For example, “grumpy cat” a cat made famous by her coverage on social media, achieved her moniker due to her perceived “frowning” facial appearance.  However, this was likely a result of a combination of her feline dwarfism and paedomorphic [infant-like] features, rather than an expression of her irritability.

One interesting point the authors make is that one possible reason that cats in general have fewer facial cues to solicit nurturing from humans is that they've been in domestication as companions for a far shorter time than dogs have.  The human/dog relationship goes back millennia; and while cats have been used as mousers for centuries, their use as companion animals is of fairly recent origin.  In fact, a large percentage of current domestic cat breeds are under a hundred years old -- in other words, if you trace most "pure-bred" cats' ancestry back two hundred years, they all descend from a population of generic-looking felines that began to be heavily selected when people started keeping them in their homes, and expecting something more out of them than just ridding the house of rodents.

In any case, as the authors point out, the advantage to the pet is obvious.  In our case, our dogs play us like fiddles.  One of our current dogs, a lovable big galoot named Guinness, knows that to get what he wants all he has to do is put his head in my lap and just stand there.  I've tried ignoring him, but he knows that patience always gets him what he wants (usually petting) in the end.  If I make eye contact with him, the tail starts wagging, because he knows he won.

As usual.

But as my wife points out, the fact that they've evolved to yank on our heartstrings isn't entirely a one-way relationship.  We get companionship and love and lap-warming, and there's real value in that.  So really, I'm perfectly okay with being used.  A petless home would be a lot cleaner and quieter, but it would also be a lot colder, lonelier, and sadder.

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As a biologist, I've usually thought of myself as immune to being grossed out.  But I have to admit I was a little shocked to find out that the human microbiome -- the collection of bacteria and fungi that live in and on us -- outnumber actual human cells by a factor of ten.

You read that right: if you counted up all the cells in and on the surface of your body, for every one human cell with human DNA, there'd be ten cells of microorganisms, coming from over a thousand different species.

And that's in healthy humans.  This idea that "bacteria = bad" is profoundly wrong; not only do a lot of bacteria perform useful functions, producing products like yogurt, cheese, and the familiar flavor and aroma of chocolate, they directly contribute to good health.  Anyone who has been on an antibiotic long-term knows that wiping out the beneficial bacteria in your gut can lead to some pretty unpleasant side effects; most current treatments for bacterial infections kill the good guys along with the bad, leading to an imbalance in your microbiome that can persist for months afterward.

In The Human Superorganism: How the Microbiome is Revolutionizing the Pursuit of a Healthy Life, microbiologist Rodney Dietert shows how a lot of debilitating diseases, from asthma to allergies to irritable bowel syndrome to the inflammation that is at the root of heart disease, might be attributable to disturbances in the body's microbiome.  His contention is that restoring the normal microbiome should be the first line of treatment for these diseases, not the medications that often throw the microbiome further out of whack.

His book is fascinating and controversial, but his reasoning (and the experimental research he draws upon) is stellar.  If you're interested in health-related topics, you should read The Human Superorganism.  You'll never look at your own body the same way again.

[Note:  if you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]

Puppy dog eyes

Conversation between Carol and me a few days ago:

Me:  Honey, I think Guinness is sad. 

Carol:  Sad?  What does he have to be sad about?  He spends his whole day sleeping, playing, and eating. 

Me:  I dunno.  But just look at him.

Carol:  That's not sad, he just wants something. 

Me:  See?  He needs something.  That's what's making him sad. 

Carol:  He's just manipulating you. 

Me:  Is not. 

Carol:  Is too.  That dog has you wrapped around his little paw. 

Me:  [to Guinness]  I'm sorry, buddy.  I guess Mommy just doesn't love you as much as I do. 

Guinness:  *heavy sigh* 

Carol:  *eyeroll*

Turns out, much as I hate to admit it, a piece of research that came out in the Proceedings of the National Academy of Sciences last week suggests that Carol is probably correct.  In "Evolution of Facial Muscle Anatomy in Dogs," by Juliane Kaminski, Bridget M. Waller, Rui Diogo, Adam Hartstone-Rose, and Anne M. Burrows, we learn that since domestication, dogs have experienced significant evolution of one specific set of muscles, as compared to wolves.  The authors write:

Domestication shaped wolves into dogs and transformed both their behavior and their anatomy. Here we show that, in only 33,000 years, domestication transformed the facial muscle anatomy of dogs specifically for facial communication with humans.  Based on dissections of dog and wolf heads, we show that the levator anguli oculi medialis, a muscle responsible for raising the inner eyebrow intensely, is uniformly present in dogs but not in wolves.  Behavioral data, collected from dogs and wolves, show that dogs produce the eyebrow movement significantly more often and with higher intensity than wolves do, with highest-intensity movements produced exclusively by dogs.  Interestingly, this movement increases paedomorphism [retention of juvenile-appearing characteristics] and resembles an expression that humans produce when sad, so its production in dogs may trigger a nurturing response in humans.  We hypothesize that dogs with expressive eyebrows had a selection advantage and that “puppy dog eyes” are the result of selection based on humans’ preferences.

It's not really manipulation, though, unless you call our nurturing reaction toward little children manipulation; we're evolutionarily programmed to nurture our offspring for obvious reasons.  What's interesting is that the nurturing instinct -- our reaction to round faces with large eyes and comparatively small noses, ears, and chins -- has been more or less accidentally transferred to other animals, which is why we ooh and aah over puppies, kittens, bear cubs, and so on.

What's interesting in my case -- and Carol's, too, actually, although she might hesitate to admit it -- is that we have a much stronger positive reaction to puppies than we do to children.  When family friends came over with their six-month-old baby a year ago, and asked me if I wanted to hold the baby, my reaction was:  "Um... sure."  *takes baby*  "Um... hi, baby.  You're cute.  Wow, what a cute baby."  *quickly hands baby back to the parents*

If it'd been a puppy, though?  I'd have been on the floor rolling around with the puppy and completely ignoring our friends, except insofar as to consider how I might successfully steal the puppy without their noticing.  I can't pass a dog on the street without asking the owner if it's okay if I say hi.  And dogs, for their part, seem to take to me immediately.

Kids, though?  Not so much.  Probably a lot of it is that they sense my awkwardness, but for whatever cause, dogs generally like me way more than people do.

So I guess Carol has a point about Guinness's sad look.  He's probably not really sad, he just knows when he uses it, he'll get what he wants.  Now,  y'all'll have to excuse me, because I need to go... um... outside for...  a reason.  Yes, I have a tennis ball in my hand.  That's just a coincidence.   Maybe I'll have some use for it later.  You never know when a tennis ball might come in handy.

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This week's Skeptophilia book recommendation is a little on the dark side; Jared Diamond's riveting book Collapse: How Societies Choose to Fail or Succeed.  Starting with societies that sowed the seeds of their own destruction -- such as the Easter Islanders, whose denuding of the landscape led to island-wide ecological collapse -- he focuses the lens on the United States and western Europe, whose rampant resource use, apparent disregard for curbing pollution, and choice of short-term expediency over long-term wisdom seem to be pushing us in the direction of disaster.

It's not a cheerful book, but it's a very necessary one, and is even more pertinent now than when it was written in 2005.  Diamond highlights the problems we face, and warns of that threshold we're approaching toward catastrophe -- a threshold that is so subtle that we may well not notice it until it's too late to reverse course.

[If you purchase this book using the image/link below, part of the proceeds goes to support Skeptophilia!]