Born to Be Good: The Science of a Meaningful Life

Bachorowski then conducted microscopic analyses of the fundamental acoustics of laughs. This laborious work yielded three clues to the deep meaning of laughter, and why it emerged in human evolution. The first clue helps us to begin to make sense of the astounding varieties of laughter. Bachorowski has differentiated between what she calls voiced laughs, which have tone to them and involve vibrations of the vocal folds (chords), and unvoiced laughs, which do not. Voiced laughs sound like songs, rising and falling as they move through space. Other people perceive these laughs as invitations to friendship and camaraderie. Unvoiced laughs—hisses, snorts, grunts—are not perceived as such. Much as the language of smiles is divided into Duchenne and non-Duchenne smiles, there are voiced laughs of pleasure and unvoiced laughs not involving pleasure. In his remarkable meditation on laughter, The Book of Laughter and Forgetting, Milan Kundera writes about two kinds of laughs. The laugh of the devil denies the rational order of the world. The laugh of the angel affirms the beauty of things and brings lovers, friends, and comrades together in common purpose in an elevated state above the earthly ground. Voiced laughs are Kundera’s laughs of angels and unvoiced laughs those of the devil. Both are vital to the social contract.

Bachorowski made a second crucial discovery in analyses of how the laughs of individuals play off one another like the sounds of different instruments in an orchestra. The laughs of friends, as opposed to those of strangers, start out as separate vocalizations but quickly shift to become overlapping, intertwined sounds whose acoustic qualities mimic each other. Bachorowski deemed these laughter duets antiphonal laughter. This is the kind of laughter that unites people in affection. Friends, when responding to humor and levity, quickly find a common place in acoustic space for sharing laughter; their minds are united in two-to three-second periods of antiphonal laughter.

Finally, Bachorowski identified where laughs fall in acoustic space compared to consonants and vowels. Here a remarkable discovery: Laughs occupy a part of acoustic space that is different from vowel sounds like “ahhh” and “eee.” We may describe laughs in the written word as “ha, ha, ha” or “hee, hee, hee,” but in fact the acoustic structure of laughter is distinct from that of the vowels we use to represent this mysterious category of behavior. Certain regions of the human vocal apparatus produce the vowels and consonants that make up human speech, in which so much of human social life transpires. But there is another register of the human vocal apparatus, another form of output—laughter—with different origins and functions than human speech.

In light of Bachorowski’s discoveries, it is now assumed that laughter preceded language in human evolution, emerging in early protohuman form some four million years ago. This is significantly earlier than when humans started to put together vowels and consonants into phonemes, and those phonemes into words and sentences. Recent neuroscientific data on laughter, summarized by Willibald Ruch, one of the leading laughter scientists, yields a similar conclusion about the early appearance of human laughter in evolution. Ruch has synthesized numerous brain studies of laughter. Some focused on the brain correlates of pathological laughter. For example, people who suffer from a syndrome known as pseudobulbar affect will abruptly break into uncontrollable laughter in response to inappropriate stimuli—the tilt of a head, the movement of a hand, a trivial comment in a conversation. In other studies, laughter was observed following electrical stimulation to specific regions of the brain. When people laugh, subcortical, limbic regions of the brain and brain stem—most notably a region known as the pons, which is involved in sleep and breathing—are activated. These regions are much older evolutionarily than the cortical regions involved in language, suggesting that the deeper meaning of laughter is intertwined with breathing.

WHAT’S SO FUNNY ABOUT LAUGHTER

 

Laughter, then, is social and contagious. It empties the air deep in the cavities of our lungs, allowing heart rate and blood pressure to drop, the muscles of fight/flight exertion to go limp, and our psyche to fall into a calm state. These laughter facts fit nicely with the most enduring notion about the meaning of laughter, that it is the behavioral output of the experience of humor. Humor is as difficult to deconstruct as laughter, but there is consensus about the canonical structure of humorous acts: they involve some juxtaposition of contradictory propositions that produces a state of tension and ambiguity. The resolution of that contradiction then arrives in the form of a conceptual insight or punchline, the contradiction is resolved, and we laugh.