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.

Life after Dying? Absolutely

I and many – not all – of the people I know feel quite sure that life ends at death. And yet we rely on an afterlife of a natural kind: other people’s lives will continue after we have gone. If people did not believe that was so, life would lose much of its meaning.

So argued philosophy professor Samuel Scheffler in “The Importance of the Afterlife. Seriously” in the New York Times back on September 21, 2013.

Because we take this belief [that the human race will survive after we are gone] for granted, we don’t think much about its significance. Yet I think that this belief plays an extremely important role in our lives, quietly but critically shaping our values, commitments and sense of what is worth doing. Astonishing though it may seem, there are ways in which the continuing existence of other people after our deaths—even that of complete strangers—matters more to us than does our own survival and that of our loved ones.

(youtube)

To make his point, Scheffler offers this doomsday scenario.  “Suppose you knew that although you yourself would live a long life and die peacefully in your sleep, the earth and all its inhabitants would be destroyed 30 days after your death in a collision with a giant asteroid. How would this knowledge affect you?” It is reasonable, he says, to imagine people losing the motivation to research cancer, to reform society, to compose music, and perhaps even to have children.

Scheffler’s discussion has personal relevance for me. I’ve written about my occasional flashes of panic that when I die, not only will my life cease but so will my past, along with the lives of everyone I know and perhaps the entire universe. I described the fear thus:

These flashes of annihilation come at me seemingly out of nowhere. My gut tightens and there is an instant of blur and panic until I catch something else to think about. The suddenness is like the flash of some frightening memory from childhood or like the imagining of a car crash. The odd thing is that the sudden blankness sometimes includes my surroundings along with me.

I compared my experience to that of the child who closes his eyes and thinks that because he can’t see anyone, no one can see him. Except that my reaction is fear, not delight.

Lives (legacy.com)

I haven’t had such panicky moments now for several years. A couple of thought streams have helped. The first I mentioned in the  early post. I bring my attention to all the significant people – from family members to national leaders – who have died without the world ending. In fact, I wrote, “Every year we are surrounded by the deaths of plants and animals of every description and beyond counting, death on such a scale there might well be reason to fear an apocalypse. Yet none occurs.” And among the benefits of a funeral, I suggested, is the opportunity for the living to be reassured that the death of one of their own will not jeopardize the existence of the others.

I’ve also been reading about how the activities of any organism, even a bacterium, consist of refueling, protecting, repairing, and reproducing itself. Each living thing is alive by virtue of the fact that it – we all – try to avoid harm, seek out energy sources, reproduce. So it is not just that organisms prepare for the future. It is that being alive in the first place is to be a mechanism for continuity.

Learning about such basics of biology puts the existence of life on a solid ground that I hadn’t quite felt before. And it helps me understand why believers in traditional religions seem so confident about their afterlives.