S Y N A P S I S

James Belarde //

“He was born with a gift of laughter and a sense that the world was mad.” -Rafael Sabatini, in Scaramouche

Have you ever been to a party hosted by a three-month-old baby? Neither have I, but wonder what that might look like? Maybe some formula milk mocktails and mashed peas laid out on a table (a short one, naturally), a shaker toy for everyone to keep occupied, and plenty of room on the floor for guests to lie down and just wriggle? All while the sounds of Raffi’s “Baby Beluga” ripple out from a record player in the corner (of course this cool baby is up-to-date on vintage vinyl music trends)? Fortunately, my surreal, borderline terrifying vision has almost certainly never taken place. But infant-hosted parties do exist and were an important part of a celebratory milestone in at least one cultural tradition: the A’wee Chi’deedloh (“The Baby Laughed”) ceremony observed by the Navajo (or Diné) Native Americans.

The A’wee Chi’deedloh is a celebration held to commemorate a baby’s first laugh. At around three months-old, family and friends would watch the infant closely for that first musical giggle parents delight in hearing. They would even attempt to elicit it, and when the baby did laugh, it was time for the little one to go straight from its first laugh to hosting its first party (they grow up so fast!). Of course, an infant cannot host a party (see my detailed absurdist nightmare above), so the one responsible for earning the child’s first laugh hosts the event on their behalf, helping hand out gifts to the many guests invited and facilitating the celebration’s proceedings. This tradition is rooted in the Diné belief that a newborn has a proverbial foot in two worlds, the spirit one and the physical one. The first laugh indicates the infant’s desire to leave the spirit world and join their family and larger community on earth. In other words, the baby is ready to become a social being.¹ This belief underlying the A’wee Chi’deedloh shows an intuitive understanding of the most defining feature of laughter: it exists primarily as a social phenomenon. But how did human laughter originate?

As I discussed with smiling in my last article,² laughter is also a globally recognized human behavior that occurs in a variety of situations. Though laughter today is most often associated with humor and comedy, it can occur when we’re amused, nervous, embarrassed, or even frightened. Further complicating its function in society, humans laugh in both sincere displays of goodwill toward others and instances of hostile humiliation. In fact, just as smiles can be classified as Duchenne or non-Duchenne depending on whether they are accompanied by a genuine feeling of joy or not, respectively, laughter can also have Duchenne and non-Duchenne classifications.³ But despite these similarities to the smile and the tendency for the two phenomena to coexist, the field of gelotology (“the study of laughter”) usually stresses that smiling and laughter have quite distinct evolutionary origins.

Throughout recorded history, laughter is most commonly associated with humor, resulting in some theories suggesting it evolved alongside, or immediately after, language. This is because humor is often seen as verbal or conceptual play that requires the existence of a complex communication system. Proponents of this theory believe laughter is a physical manifestation of such verbal recreation. However, many observations cast doubt on this thinking. Babies produce laughter long before they start fumbling with speech sounds. Even infants born congenitally blind and deaf are reported to express laughter normally. Nevertheless, the development of speech in these children is hindered, and they require extensive support to acquire verbal ability.³

Further evidence against the theory of laughter evolving after speech comes from patients with brain damage that results in a neurological condition called pseudobulbar palsy (PBP). PBP is a term used to describe patients who experience frequent, uncontrollable episodes of laughter and crying despite having no emotional stimulus for this behavior. Though caused by all sorts of brain injuries including stroke,⁴ trauma,⁵ Parkinson’s,⁶ and other degenerative disorders,⁷ the underlying principle is the same: the more evolutionarily advanced cerebral cortex of the brain (responsible for things like language acquisition) is damaged and loses its normal ability to regulate and repress the more primitive regions of our brain (such as the brainstem). This results in uncontrolled laughing, further supporting the idea that laughter is older than speech. Medical therapies aimed at strengthening these weakened control networks from the cortex are the most effective options in reducing the constant laughter,⁸ providing greater support for the idea that laughter is produced by more ancient evolutionary structures.

There are even developmental disorders that reflect this same pattern. Angelman syndrome is a condition defined by abnormal brain development. Among symptoms like epilepsy, movement disorders, and intellectual disability, Angelman patients are frequently noted for their persistent happy affect and bouts of unprovoked laughter.⁹ As one might expect from the discussion above, the highly evolved cerebral cortex is the area most affected in these children.

But if laughter predates speech and didn’t evolve as an indicator of verbal play the way some humor studies have suggested, what was its original function? To answer this, gelotologists look to the behavior of our closest primate relative, the chimpanzee. Though Aristotle held that laughter was uniquely human, some other mammals have laugh-like vocalizations, and this includes the “play-pant” of chimps. Most often mistaken for a dog panting in studies where the sound is played for human listeners (as opposed to human laughter which is almost unanimously identified as such), the chimpanzee play-pant always occurs in situations in which we might expect laughter, such as during playful games or tickling. Classified as a sort of primate onomatopoeia, it mimics the labored breathing of physical exertion but signifies a playful intent rather than true exhaustion.¹⁰ Thus, this faux panting is a sound of joyful play, just like a human’s Duchenne laugh.

Still, modern human laughter is used for so much more than play, as discussed above. If the play-pant is a type of primitive laugh, how did ours develop into the multipurpose tool it is today, one that can be used for both joy and derision? The highly social nature of the A’wee Chi’deedloh celebrated by the Navajo people may provide an important clue—one that I’ll discuss in full in the sequel to this piece. For now, as an apology for such a nail-biting cliffhanger, I’ll offer a favorite joke of mine from a stand-up comedy idol, Mitch Hedberg. Consider it another prelude to addressing this question in my next article. “I bought a parrot. The parrot talked, but it did not say ‘I’m hungry,’ so it died.”

References

1. Lee, Ingrid Fetell. “The Navajo celebration of a baby’s first laugh.” The Aesthetics of Joy, 5 Oct. 2016, https://www.aestheticsofjoy.com/2016/10/navajo-celebration-babys-first-laugh/. Accessed on 1 Sept. 2019
2. Belarde, James. “The Smile: A Confusing Expression for Every Occasion.” Medical and Health Humanities, 24 June 2019, https://medicalhealthhumanities.com/2019/06/24/the-smile-a-confusing-expression-for-every-occasion/. Accessed on 30 Aug. 2019
3. Gervais, M. and Wilson, D. S. “The evolution and functions of laughter and humor: a synthetic approach.” Quarterly Review of Biology. 2005; 80:395-430.
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7. Christidi, F., Karavasilis, E., Ferentinos, P., Xirou, S., Velonakis, G., Rentzos, M., Zouvelou, V., Zalonis, I., Efstathopoulos, E., Kelekis, N., and Evdokimidis, I. “Investigating the neuroanatomical substrate of pathological laughing and crying in amyotrophic lateral sclerosis with multimodal neuroimaging techniques.” Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration. 2018; 19:12-20.
8. Shin, S. H., Kim, Y. W., and Kim, N. Y. “Treatment of poststroke pathologic laughing with duloxetine: a case series.” Clinical Neuropharmacology. 2019; 42:60-63.
9. Buiting, K., Williams, C., and Horsthemke, B. “Angelman syndrome – insights into a rare neurogenetic disorder.” Nature Rev Neurology. 2016; 12:584-593.
10. Provine, Robert R. “Laughter as an approach to vocal evolution: the bipedal theory.” Psychon Bull Rev. 2017; 24:238-244.