Usage: To laugh is human ("Man is the only animal who laughs," noted the French philosopher Henri Bergson; but see below, Primatology I). Chemically, according to some researchers, laughter provides relief from stress by releasing pain-killing, euphoria-producing endorphins, enkephalins, dopamine, noradrenaline, and adrenaline. Socially, laughter binds us as friendly allies united against outsiders, and against forces beyond our control. Psychologically, the comic laugh (in response, e.g., to funny jokes, puns, and satire) is a recent development perhaps linked to the evolution of speech (see below, Speech).

Anatomy. 1. Diverse facial, jaw, and throat muscles are involved in the laugh, including levator labii superioris, risorius, mentalis, depressor anguli oris (the "frown" muscle), orbicularis oris, buccinator, and depressor labii inferioris (Ruch 1993). 2. Laughter may be accompanied by a general lowering of muscle tonus and an increase in bodily relaxation, leading one, e.g., to "collapse in laughter" (see Ruch 1993). 3. In laughing, the abdominal muscles and diaphragm contract in a respiratory "fit," not unlike sneezing or crying. Zygomatic and risorious muscles of the face contract in a grimacing smile; mandibular muscles may rhythmically contract as the lower jaw quivers. In a belly laugh, heartbeat accelerates, blood pressure rises, and vocal cords may uncontrollably vibrate.

Conscious control. "Does the low level of conscious control that we have over our own laughter reflect the typical level of control that non-human animals have over their own species-typical vocalizations?" (Provine 1996).

Contagious laughter. "Consider the bizarre events of the 1962 outbreak of contagious laughter in Tanganyika. What began as an isolated fit of laughter (and sometimes crying) in a group of 12- to 18-year-old schoolgirls rapidly rose to epidemic proportions. Contagious laughter propagated from one individual to the next, eventually infecting adjacent communities. The epidemic was so severe that it required the closing of schools. It lasted for six months" (Provine 1996).

Exhilaration. Laughter is frequently associated with--and thus may be a sign of--the emotion of exhilaration (Ruch 1993). According to Ruch (1993), exhilaration is a "pleasurable, relaxed excitation" which begins with a "sudden and intense increase in cheerfulness, followed by a more or less pronounced plateau and a prolonged fading out of the emotional tone."

Life history. The human laugh is partly learned, partly familial, and so highly contagious that we readily respond to televised "canned laughter" (see MEDIA, "TV II"). As infants, we laugh reflexively near the 10th week of life. When very old we may cackle, as the larynx becomes inelastic with age.

Literature. 1. "There was laughter of warriors, voices rang pleasant, words were cheerful." --Beowulf. 2. "And Laughter, holding both his sides." --John Milton (L'Allegro; ca. 1630).

Media. According to Esquire magazine, more than anything else, women want men to make them laugh (Spokesman-Review, Feb. 7, 1999).

Primatology I. Stimulated by the mammalian brain, laughter has much in common with animal calls. Gorillas and chimps "laugh," e.g. (i.e., give breathy, panting vocalizations), when tickled or playfully chased.

Primatology II. "It is noteworthy that chimpanzee laughter occurs almost exclusively during physical contact, or during the threat of such contact, during chasing games, wrestling or tickling. (The individual being chased laughs the most.) Although people laugh when tickled, most adult human laughter occurs during conversation, typically in the absence of physical contact" (Provine 1996).

Solitary laughter. "In the absence of stimulating media (television, radio or books), people are about 30 times more likely to laugh when they are in a social situation than when they are alone" (Provine 1996).

Speech. 1. "One of the key features of natural laughter is its placement in speech. Laughter is not randomly scattered throughout the speech stream. The speaker and the audience seldom interrupt the phrase structure of speech with laughter. In our sample of 1,200 laughs there were only eight interruptions of speech by laughter, all of them by the speaker. Thus a speaker may say 'You are going where? . . . ha-ha,' but rarely 'You are going . . . ha-ha . . . where?' The occurrence of laughter during pauses at the end of phrases suggests that a lawful and probably neurologically based process governs the placement of laughter in speech--a process in which speech has priority access to the single vocalization channel. The strong and orderly relationship between laughter and speech is akin to punctuation in written communication (and is called the punctuation effect)" (Provine 1996). 2. ". . . the average speaker laughs about 46 percent more often than the audience" (Provine 1996).

RESEARCH REPORTS: 1. ". . . it is scarcely possible to point out any difference between the tear-stained face of a person after a paroxysm of excessive laughter and after a bitter crying-fit" (Darwin 1872:207). 2. Laughing strengthens bonds of comradeship (Van Hooff 1967:59). 3. Laughter is more social than humorous (Van Hooff 1967:59). 4. Our laugh resembles the great ape's relaxed open-mouth face (esp., its "rhythmic, low-pitched staccato vocalizations and . . . boisterous body movements" (Van Hooff 1967:60). 5. "For example, they [deaf-and-blind-born children] smile and laugh as we do when they are happy and emit the correct sounds when they do so" (Eibl-Eibesfeldt 1971:12). 6. People in good spirits may laugh 100-to-400 times a day (Fry 1983). 7. Human laughter "seldom exceeds 7 seconds" (Ruch 1993). 8. Laughter may be vocal or voiceless, may include all vowel and many consonant possibilities; it frequently begins with an initial "h" sound, most usually as "he-he," grading into "ha-ha" (Ruch 1993). 9. Robert Provine, who studied 1,200 bouts of laughter in malls and public places, characterized the verbal remarks the laughing accompanied as "not funny" (Angier 1996). 10. Provine found that a. laugh vocalizations last about 75 milliseconds, separated by rests of 210 milliseconds; b. average speakers laugh 46% more than listeners; c. male speakers laugh only slightly more than male listeners; d. female speakers laugh considerably more than female listeners; e. male speakers laugh 7% less than female listeners; f. female speakers laugh 127% more than male listeners; and g. speakers usually laugh at the end of complete phrases (rather than in the middle), as a kind of nonverbal punctuation.

Neuro-notes I. Visual, auditory, tactile, and vestibular (but rarely smell or taste) cues stimulate laughter's complex, reverberating chain of events involving areas of the brain stem, hypothalamus, and frontal lobes, as well as centers of the motor and cognitive cerebral cortex.

Neuro-notes II. 1. "Researchers may have found the location of [the] sense of humor in the brain, according to their presentation at the 86th Scientific Assembly and Annual Meeting of the Radiological Society of North America (RSNA) in Chicago, Illinois. Humor appreciation appears to be based in the lower frontal lobes of the brain, a location associated with social and emotional judgment and planning, according to imaging research" (Flapan 2000). 2. "'As with almost any behavior, we found that laughing at a joke involves several parts of the brain,' said Dr. [Dean K.] Shibata [assistant professor of radiology at the University of Rochester School of Medicine in New York]. 'Our [fMRI] imaging results show that while the ventromedial frontal lobe is likely the center for telling you what's funny, the accompanying laughter and feeling of mirth may be triggered by connections to other areas of the brain [including the nucleus accumbens; see PLEASURE CUE] which are involved in motor control [moving the mouth] and positive emotions'" (Flapan 2000).

Neuro-notes III. Mirror neurons: As in human beings, the laughter of an individual chimpanzee can trigger imitative laughter in chimps nearby (source: Davila-Ross, Marina; Allcock, Bethan; Thomas, C.; and Kim Bard (2011). "Aping Expressions? Chimpanzees Produce Distinct Laugh Types When Responding to Laughter of Others," in Emotion, Vol. 11, No. 5, pp. 1113-20). In both species, imitative laughter is likely due to mirror neurons.

Neuro-notes IV. Mirror neurons: "Rapid facial mimicry (RFM) is an automatic response, in which individuals mimic others' expressions. RFM, only demonstrated in humans and apes, is grounded in the automatic perception-action coupling of sensorimotor information occurring in the mirror neuron system. In humans, RFM [as in laughing] seems to reflect the capacity of individuals to empathize with others. Here, we demonstrated that, during play, RFM is also present in a cercopithecoid species (Theropithecus gelada) [in the "play face," thought to be homologous with human laughter]." [Source: Mancini, Giada, Ferrari, Pier F., and Elisabetta Palagi (2013). "Rapid Facial Mimicry in Geladas." In Scientific Reports (Vol. 3, 28 March 2013; http://www.nature.com/srep/2013/130328/srep01527/full/srep01527.html).]

See also ISOPRAXISM.

Copyright 1998 - 2016 (David B. Givens/Center for Nonverbal Studies)
Photo of "Smile, Surfacing" (Fiesta Mexicana, Spokane, Washington, USA) by Doreen K. Givens (copyright 2007)