The Evolution of Laughing and Crying

How have we humans come to be so skillful at smiling, laughing, and crying? Other notable human behaviors – reproducing, fighting, sharing, hunting –  have easily visible predecessors among most animals. But our repertoire of daily grins, laughs, and tears – except for some vaguely similar expressions among chimps, dogs, and rats – is unique. We express life’s joys and sorrows in ways that seem to have little ancestry.

But neuroscientist Michael Graziano proposes that we smile, laugh, and cry in useful mimicry of a protective, cringing reflex that is millions of years old.

In The Spaces Between Us: A Story of Neuroscience, Evolution, and Human Nature (2018), Graziano describes his team’s years of research at Princeton on how the brain monitors the personal space around us. This flexible buffer zone can extend out to the edges of the car we are driving or to our child who is leaning over a ledge. The buffer also shrinks to the physical closeness we allow with those we trust and even disappears altogether for pair bonding and sex. The buffer is a protective, not a social space. “Personal space is all about the zone where you keep people out, not the zone where you invite people in” (Kindle location 472).

Cringe (mikecrudge.com)

So where do smiling, laughing, and crying come in? Such expressive reactions are rooted in an ancient cringe posture that people still take on when their protective zone is suddenly and dangerously threatened – by seeing a stone thrown at them, for example. The posture reflects the brain’s first priorities: protect the eyes and the abdomen. “The forehead is mobilized downward and the cheeks are mobilized upward, dragging the upper lip with them.” As a result, the teeth are exposed. Hands cover the abdomen, the body hunches down, shoulders rise.

Smiles (Mount Pleasant Granary)

We think of a smile as being about teeth, but the display of teeth is only a consequence of the cheeks lifting upward to protect the eyes. Still, the sight of this wincing “smile” may have reassured an early enemy that the individual in the cringe posture was not a threat. But the potential victim learned even more: that the facial expression could be imitated, mimicked, in order to ward off injury, to play it safe. Millions of years later, we smile.

Graziano states his point carefully. “…[T]o be clear, the human smile is not a defensive cringe. When you smile, you are not thereby protecting your eyes from a flying stone. You’re not expressing fear. You’re not anticipating an attack. But the evolutionary precursor of a smile is a defensive cringe that protects the eyes in folds of skin. A smile is an evolutionary mimic” (2255).

 

Laughter (pngimage.net)

While the smile mimics a gesture that might have headed off a conflict before it started, laughter may have emerged as a way to prevent harmless play-fighting already in progress from getting too serious. Graziano connects laughter with tickling. When a child is tickled, the hand of the tickler moves into the child’s protective space, the cringe reaction begins to sound the alarm, the hand reaches an area of sensitive skin and “the touch evokes a full-blown laughter…an entire collection of alarm shrieks, defensive blocking and retracting, a pursing of skin around the eyes, upward bunching of the cheeks, upper lip pulling up, and secretion of tears”(2316). Laughter evolved from such an alarm reaction that tells a play-opponent that yes, you’ve touched me, touché, now that’s enough. Like the smile, laughter gradually became a social signal, read by others, mimicked by those who want to signal their good-natured agreeableness.

Graziano acknowledges that such speculation does not explain the many types of laughter – or the nature of humor itself. But it does suggest why, after the long road of its evolution, full and hearty laughter shares many of the facial markers of the defensive cringe.

Crying (youtube)

Crying, unlike smiling and laughing, adapts the cringe response to the loser’s need for friendly resolution after an all-out fight is over.  After an attack, a primate victor often comforts the loser. The loser’s cringing, moaning, and tears signal not only surrender but a plea to restore amity. After a million years of such reactions, we mimic the post-drubbing defensive cringe as a way to express pain and ask for consolation – even when we are crying alone.

Graziano’s book is very clear, very engaging, and at times very personal. And I value knowing how laughter and tears both link us to early ancestors while also displaying such an evolutionary distance from the original reflex.

Six Interesting Ways That Cars Are Like People

Cars are a favorite metaphor and mirror for us humans, from their vroom for the young to the creaks and breakdowns for the aging. The comparisons would seem to have been exhausted, but I keep running into new ones. Here are a few.

(thehiat.blogspot.com)

(thehiat.blogspot.com)

Some car comparisons occur to us because we can say that under certain circumstances, cars “die.” Atul Gawande discusses one aspect of how they do that in his book, Being Mortal: Medicine and What Matters in the End, although he mentions cars only once. He is explaining why genetics has little to do with how long we will live.

The classical wear-and-tear model may explain more than we know. Leonid Gavrilov, a researcher at the University of Chicago, argues that human beings fail the way all complex systems fail: randomly and gradually. As engineers have long recognized, simple devices typically do not age. They function reliably until a critical component fails, and the whole thing dies in an instant. [But complex systems with thousands of parts are engineered with layers of backup systems. And so are we.] We have an extra kidney, an extra lung, an extra gonad, extra teeth.

Nonetheless, as the defects in a complex system increase, the time comes when just one more defect is enough to impair the whole, resulting in the condition known as frailty. It happens to power plants, cars, and large organizations. And it happens to us: eventually, one too many joints are damaged, one too many arteries calcify. There are no more backups. We wear down until we can’t wear down anymore.

And then there’s oxidation. Here’s an excerpt from a booklet, Circumin: The 21st Century Cure, by Jan McBarron, MD, about anti-oxidants and the health benefits of a component of the spice turmeric:

Think about the rust on the bumper of a car. Rust is caused by oxidation or damaging oxygen molecules that corrode and eventually destroy the structure of metal. These same corrosive oxygen molecules…are found inside the human body…and contribute to the deterioration of cells.

The idea of a living car is cute Disney but unappealing otherwise, since it is the human driver who brings it to life. (johnwarrand.com)

The idea of a living car is cute but unappealing otherwise, since the attraction of a car is that it is we ourselves who bring it to life.
(johnwarrand.com)

Number three: Biologist Ursula Goodenough brings up car engines to make the point that while some random changes in the genes of organisms may work to our species’ benefit, those genes that set up the basic processes of cell assembly and maintenance have been humming along in all living things for billions of years. So organisms keep these efficient “housekeeping genes,” as she calls them, just as they are. “Changing them is like randomly modifying a carburetor or a timing belt after it’s already in synch with the rest of the engine: the usual outcome is that the car fails to run properly and often, as we say, the engine ‘dies’.”

I don’t remember where I read the idea behind number four: cars are like people in that both result from gradual processes of selection. For cars, the selector is not nature but the competition of the automotive marketplace. Any particular trait of a car or an organism will endure only if the versions that carry the trait succeed sufficiently to be widely reproduced.

Another evolutionary similarity. Cars are made to move. For humans too, motion has shaped us. Our oldest claim to organic uniqueness is that we walk on only two legs without a tail or feathers for support. Six million years ago, our ancestors clumsily rose up from four feet to two in order to get a better look as they walked across the savannah. The change helped trigger changes in our eyes, hands, legs, and brains. We, like cars, are made to move, and moving, in turn, made us.

Force and focus behind the wheel (www.zco.com)

At the controls
(www.zco.com)

Finally and more philosophically, the driving experience echoes the way that we experience ourselves as a mind inside a body. Cars give us an opportunity to be a heightened version of our brain-in-a-body selves. Most of the time we might feel like just a mishmash of thoughts inside a squishy physique. But put us in the driver’s seat and we’re a bigger, sleeker animal and a laser-like self.

The comparison goes further. We humans construct many entities besides cars that we can get into or put on—and in some sense “bring to life.” They include not only planes, trains, and ships but also clothes, buildings, novels, and even gods. In each of these, we position ourselves to be protected and enhanced and can readily identify with or personify the thing itself. We build and live in our protective houses and decorate them to make them reflections of ourselves. We “live” in the novels we read (or write) and imagine the living characters. And most strangely, we build gods and heroes by animating them with powers, passions, and virtues that we wish we had. All of these are cars of sorts, to transport and intensify us.