Week 3

Beyond the Classical Theories

  • Elaboration component

    • The degree to which people use activated schemas to generate further thoughts, images, and inferences related to the reinterpretation of an event that are not necessary for comprehension

Benign-Violation

  • The cognitive analogy of “tickle“ in which we demonstrate both signs of discomfort (e.g. grimaces) and pleasure (e.g. smiling, laughing; Harris Alarado, 2005)

  • Tickle from Friend vs. Stranger (not benign) vs. Self (not a threat) (Fridlund & Loftis, 1990)

  • Perhaps developed from rough and tumble play, as we got more complex so did the list of things in this category expanded

  • The Darwin-Hecker hypothesis: ticklish laughter is
    a reflexive, involuntary response that evolved as a
    social bonding mechanism
    ● Ticklish laughter is similar to humorous laughter, but
    is distinct in that it is less controllable and linked to
    physical touch
    ● Darwin: laughter from tickling is a primitive form of
    communication that helped to establish social bonds,
    especially during playful interactions.
    ● Hecker extended: tickling can produce reflexive
    laughter even when the tickler's intent is not
    humorous, indicating a physiological response rather a cognitive one

consider the bizarre events of the 1962 outbreak of contagious laugh? ter 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. The Tanganyikan laughter epidemic is a dramatic example of the infectious power of laughter something that many of us may have experienced in our own lives. Many readers will be familiar with the laugh tracks of television situation comedies attempts to stimulate contagious laughter in viewers and the difficulty of extmguishing their own "laugh jags/' fits of nearly uncontrollable laughter. Have you ever been overcome by a comparable urge to chant "hello-hello-hello?" Rather than dismissing contagious laughter as a behavioral curiosity, we should recognize it and other laugh-related phenomena as clues to broader and deeper issues. Clearly, laughter is a powerful and pervasive part of our lives an important component of that biobehavioral bedrock of our species known as hu? man nature. Laughter's significance has been recognized at various times and in various ways by such scientific and philosophical dignitaries as Aristotle, Kant, Darwin, Bergson and Freud. Yet aside from a general appreciation that laughter is good for us? "the best medicine" and is somehow associated with humor, we know little about laughter itself. My approach to understanding laughter is one that a visiting extraterrestrial might take were it to encounter a group of laughing human beings. What would the visitor make of the large bipedal animals emitting paroxysms of sound from a toothy vent in their faces Area sonable approach would be to describe the simplest and most obvious aspects of the noisy behavior: its physical characteristics, the rules that govern its ex? pression, characteristics of the animals emitting the sounds (such as gender), the mechanism of sound production, and whether similar sounds are made by related species. To Earthlings this naturalistic approach is known as ethology a biologically oriented scientific discipline devoted to understanding what animals do and how and why they do it. Ethologists treat behavior as an evolutionary adaptation. The species-wide distribution of laughter and its stereo? typical (and simple) structure suggests that the behavior has strong genetic and neurophysiological bases qualities attractive to those who wish to understand the mechanisms and natural history of behavior. During the past eight years I have been observing human laughter in various natural habitatsshopping malls, classrooms, sidewalks, offices and cocktail parties with the investigative spirit of our hypothetical alien. Observing everyday behavior in these set tings has provided an opportunity to appreciate laughter as a social vocalization of the human animal. These studies have produced some unexpected insights into the phenomenon of human laughter its social nature, the lawful relationship between laughter and speech, gender differences and the biological basis of contagion. Laugh Structure One of my first goals was to describe the sonic structure of human laughter. This proved to be more difficult than I expected. Like other spontaneous acts, laughter often disappears when one attempts to observe it, especially in the laboratory. Some unconventional approaches were called for. Although I could occasionally elicit laughter from friends and colleagues during playful conversations, I was often forced to engage in shameless hamming (something that graduate school did not prepare me for). One of the most productive approaches was to encounter people in public places and simply ask them to laugh. The request was usually answered with a burst of laughter. About half of the laughing subjects reported that they could not laugh on command. Indeed, we have much less conscious control over laughter than over speech. It is easy to say "ha-ha-ha," but difficult to laugh on cue. We do not "speak" laughter. In collaboration with an undergraduate assistant, Yvonne Yong, I took the recordings to the Sound Laboratory of the National Zoo in Washington, D.C. Here the laughs were analyzed with a sound spectrograph, a device that translates a sound into an image that reveals the changes in frequency and intensity of the sound over time. Giggles, shrieks and belly laughs replaced the laboratory's usual sonic fare of indigo bunting songs and the calls of golden lion tamarins. Laboratory workers gave us quizzical looks but politely refrained from asking about the origins of the sounds. The sound spectra revealed the distinct signature of laughter. A laugh is characterized by a series of short vowel like notes (syllables), each about 75 milliseconds long, that are repeated at regular intervals about 210 milliseconds apart. A specific vowel sound does not define laughter, but similar vowel sounds are typically used for the notes of a given laugh. For example, laughs have the structure of "ha-ha-ha" or "ho ho-ho," but not "ha-ho-ha-ho." There are mtrinsic constraints against producing such laughs. Try to simulate a "ha ho-ha-ho" laugh it should feel quite unnatural. When there are variations in the notes, they most often involve the first or last note in a sequence. Thus, "cha-ha-ha" or "ha-ha-ho" laughs are possible variants. The explosively voiced blasts of a laugh have a strong harmonic structure, with each harmonic being a multiple of a low (fundamental) frequency. The harmonic structure is revealed in a sound spectrogram by the evenly spaced stacks of short horizontal lines in the spectrum, the lowest of which is the fundamental frequency. Given their higher-pitched voices, it is not surprising that the laughter of females has a higher fundamental frequency (about 502 hertz) than male laughter (about 276 hertz). Whether it is a deep belly laugh or a high-pitched titter, however, all human laughter is a variation basic form. It is this structure it allows us to recognize laughter of individual differences. The notes and internote time inerval carries information that us to identify a sound as laughter sounds between laugh notes ar out of a tape recording?leav notes separated by intervals o a laugh still sounds normal. Th note time interval carries inform but the internote expiratory s not. If the notes are removed recording and the gaps betwee vals are closed, all that rem laughter is a long, breathy sigh. The Stereotypie structure of is, at least in part, a result of th tions of our vocal apparatus. It i 1996 cult to laugh with abnormally long note durations, such as "haaa-haaa-haaa," or abnormally short durations (much less than 75 milliseconds in length). Like? wise, normal note durations with ab? normally long or short internote inter? vals do not occur. Try to produce a natural laugh with a long internote in? terval, such as "ha-ha-ha." As with the natural rhythms of walking or running, there are only so many ways to laugh. laugh note position Figure 3. Decrescendo characterizes normal laughter; each note decreases in amplitude rel? ative to the previous note. The crescendo of recorded laughter played backward sounds unnatural. Here the average amplitude of eight successive notes is displayed for at least 22 subjects. The structural simplicity of a laugh is also suggested by its reversibility. A short segment of laughter?"ha-ha ha"?played backward on a tape recorder still sounds rather like "ha-ha ha." Indeed the sound spectrum of a laugh is similar whether scanned from left to right or from right to left?a laugh note has a high degree of temporal sym? metry. Yet one aspect of a laugh that is not symmetrical is its loudness. Laugh? ter is characterized by a decrescendo in which the laugh notes that are late in a sequence are usually lower in amplitude than earlier notes (presumably because we run out of air). Recordings of laugh? ter played backward produce a bizarre sounding crescendo. Chimpanzee Laughter There is a common misperception that laughter is exclusive to human beings. From at least the time of Darwin, howev? er, it has been known that diimpanzees and other great apes perform a laugh-like vocalization when tickled or during play. To pursue the details of this primate laughter, I teamed up with Kim Bard, who is nursery director and caregiver for young cWmpanzees at the Yerkes Region? al Primate Center in Atlanta. It is a plea? sure to be able to play with young diim? panzees in the pursuit of one's science. Chimpanzee (Pan troglodytes) laugh? ter differs in many ways from its hu? man counterpart. The vowel-like notes of human laughter are performed by chopping a single expiration, whereas chimpanzee laughter is a breathy panti? ng vocalization that is produced during each brief expiration and inspiration. Unlike human laughter, the laughter of a chimpanzee lacks discrete, vowel-like notes that have sharp leading and trail? ing edges on sound spectra. Chim? panzee laughter has the sound and ca? dence of a handsaw cutting wood. The sounds of chimpanzee and human laughter are sufficiently different that without viewing the characteristic "play face" and source of stimulation (such as play and tickle), naive human beings may be unable to identify the chim? panzee vocalization as laughter. You can experience the difference in produc? tion between the two forms of laughter by placing a hand on your abdomen and comparing the abdominal pulsa? tions of chimpanzee-like panting with the smoother act of speaking "ha-ha ha" during a single expiration. People laugh as we speak. If chim? panzees laugh as they speak, by pro? ducing one laugh sound per expiration and inspiration, we have identified an important and previously unrecognized constraint on the evolution of speech and language in chimpanzees and pre? sumably other great apes. The close coupling of laughter to breathing in chimpanzees may be evidence of a more general limitation on these ani? mals to speak. (In contrast to the suc? cess of teaching hundreds of signs to chimpanzees, efforts to teach them to speak English have produced meager results.) Indeed, the inability to modu? late expiratory airflow may be at least as limiting to speech as the structure of the vocal tracts of nonhuman primates. Breathy, panting laughter is probably the primal form that dates back to the common ancestor of all great apes and people. Human beings evolved their characteristic laughter after branching from an ancestor in common with chim? panzees (estimated to be around six million years ago, according to DNA hybridization data). It is noteworthy that chimpanzee laughter occurs almost exclusively dur? ing physical contact, or during the threat of such contact, during chasing games, wrestling or tickling. (The indi? vidual being chased laughs the most.)
most adult human laughter occurs dur? ing conversation, typically in the ab? sence of physical contact. Social and Linguistic Context Laughter is a decidedly social signal, not an egocentric expression of emotion. 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. Indeed people are more likely to smile or talk to them? selves than they are to laugh when they are alone. Aside from the obvious im? plication that sociality can enhance laughter and perhaps one's mood, these observations indicate that laughter has a social function. What can we say about laughter as communication? In an attempt to gather some clues, my colleagues and I have collected ob? servations on 1,200 instances of natural? ly occurring human laughter. Three un? dergraduate assistants (Lisa Greisman, Tina Runyan, Michelle Bowers) and I wandered various public gathering places where we eavesdropped on groups of laughing people. We carefully took note of the principals engaged in the behavior?the gender of the speaker and the audience, whether the speaker or the audience laughed and what was said immediately before the laughter. Contrary to our expectations we found that most conversational laughter is not a response to structured attempts at humor, such as jokes or stories. Less than 20 percent of the laughter in our sample was a response to anything re? sembling a formal effort at humor. Most of the laughter seemed to follow rather banal remarks, such as "Look, it's An? dre," "Are you sure?" and "It was nice meeting you too." Even our "greatest hits," the funniest of the 1,200 pre-laugh comments were not necessarily howlers: "You don't have to drink, just buy us drinks," "She's got a sex disorder?she doesn't like sex," and "Do you date within your species?" Mutual playful? ness, in-group feeling and positive emo? tional tone?not comedy?mark the so? cial settings of most naturally occurring laughter. Research that focuses only on the response of an audience to jokes (a common laboratory scenario) target only a small subset of laughter. 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 interrup? tions 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 neurologi cally based process governs the place? ment of laughter in speech?a process in which speech has priority access to the single vocalization channel. The strong and orderly relationship be? tween laughter and speech is akin to punctuation in written communication (and is called the punctuation effect). Our field study revealed other clues about laughter in human communica Figure 7. Experimental use of a "laugh box," which reproduces a recording of human laughter, shows that laughter by itself is a suf? ficient stimulus to elicit a response of laughter. (Photograph courtesy of the author.) tion. A counterintuitive finding was that the average speaker laughs about 46 percent more often than the audi? ence. This finding reveals the limits of analyses that report only audience be? havior?the typical approach of humor research?and neglect the social nature of the laughing relationship. The gender of the principals involved plays a large role in determining the amount of speaker laughter. Whether they are speakers or audiences (in mixed-sex groups), females laugh more often than males. Female speakers laugh 127 percent more than their male audi? ence. In contrast, male speakers laugh about 7 percent less than their female audience. Neither males nor females laugh as much to female speakers as they do to male speakers. (The lot of the female comedian is not an easy one? whether her audience is male or female.) These gender differences in the pat? tern of laughter are at least as strong as those noted for speech by the linguist Deborah Tannen of Georgetown Uni? versity. The limited cross-cultural evi? dence suggests that males are the lead? ing humor producers and that females are the leading laughers. These differ? ences are already present by the time that joking first appears around six years of age. What message is being conveyed by a laughing speaker or a laughing audi? ence? In some respects laughter may be a signal of dominance/submission or ac? ceptance/rejection. Consider the distinc? tion between laughing with and laugh ing at someone. Valuable insights about laughter's social function will come from studies of laughter in groups of people who differ in social rank and gender. A response of laughter by the audi? ence may affirm or negate the spirit of the speaker's message. "Polite" laugh? ter, for example, may be a forced effort on the part of the audience to signal their accord with the speaker, quite the opposite of the indignant "ha!" A speaker, in other cases, may buffer an aggressive comment with laughter or deliver a remark using "laugh-speak," a consciously controlled hybrid of laugh? ter and speech. Talk-show hosts, who are experts at shaping the course of a conversation, commonly use laugh speak. In this sense laughter may modi? fy the behavior of others by shaping the emotional tone of a conversation. Laugh Tracks and Contagion The use of laughter to evoke laughter or a positive mood is familiar to viewers of situation comedy shows on television. "Laugh tracks" (dubbed-in sounds of laughter) have accompanied most "sit? coms" since 7:00 p.m. (Eastern Standard Time) on September 9, 1950. On that evening the Hank McCune Shaw?a com? edy about "a likeable blunderer, a devil? ish fellow who tries to cut corners only to find himself the sucker"?first used a laugh track to compensate for the ab? sence of a live audience. Despite the fact that the show was short-lived, the televi? sion industry discovered the power of laughter to evoke audience laughter. The recording industry recognized the se? ductive power of laughter shortly after World War I with the distribution of the OKeh Laugh Record, which consisted of trumpet playing that was intermittently interrupted by laughter. It remains one of the most successful novelty records of all time. Acknowledging the commercial potential of this novelty market, Louis Armstrong, Sidney Bechet, Woody Her? man and Spike Jones all attempted to cash in with laugh records of their own. In the mtervening years social scien? tists have confirmed that laugh tracks do indeed increase audience laughter and the audience's rating of the humor ousness of the comedy material. How? ever, scientists did not consider that, in the absence of a joke or a remark, laughter by itself can evoke laughter. This is a key element in the propagation of contagious laughter. I recently performed some investiga? tions of the phenomenon of contagious laughter in an undergraduate psycholo? gy classroom. The stimulus was a "laugh box"?a small battery-operated record player from a novelty store?that emit? ted an 18-second span of laughter. The "canned" laughter was played 10 times, with the beginning of each segment sep? arated by a one-minute interval. On the first stimulus nearly half of the students reported that they responded with laughter themselves. (More than 90 percent reported smiling on the first stimulus.) However, the effectiveness of the stimulus declined with each repeti? tion until only 3 of the 128 students laughed on the tenth trial. By that point about 75 percent of the students rated the laugh stimulus as "obnoxious." The negative effect of the repeated stimulus seems to go beyond the re? sponse expected from the recurrent ex? posure to a generic auditory stimulus, such as "Hello, my name is George." The reaction may reflect the deep bio? logical significance of laughter, which in this case may be perceived as jeering or ridicule. (Colleagues whose offices ad? join my own can attest to the aversive ness of periodic canned laughter. Per? sonally, I find myself wincing every time one of the laugh boxes in my office is ac cidently activated.) Certainly it is plea? surable to laugh at or with people, but is quite unpleasant to be laughed at, or to be the recipient of a scornful "ha." Court fools and presidential aides learn early in their careers that it is safer to laugh with the boss than at him or her. The efficacy of laughter alone to elicit laughter raises the intriguing possibility that human beings have auditory "fea? ture detectors"?neural circuits that re? spond exclusively to this species-typical vocalization. In turn, the feature detec? tor triggers the neural circuits that gen? erate the stereotyped action pattern of laughter. This mechanism, involving a laugh detector that drives a laugh gen? erator, may be the foundation of conta? gious laughter. (Contagious yawning appears to involve a similar process in the visual domain.) Those who attempt to explain away their laugh-evoked (contagious) laughter as nothing more than a response to a "funny" stimulus are saying that they laughed in response to a stimulus that made them laugh, a circular argument. The structural simplicity and species typical character of laughter makes it a prime candidate for the evolution of ^^^^^^^^^^^ Figure 9. Pioneering broadcast comedian Ed Wynn set the precedent for "laugh tracks" (dubbed in laughter) in 1922 while perfonning a live comedy routine on radio solely to a microphone. The absence of audience laughter during the studio presentation so disrupted the comedian's timing that the stage crew was recruited as an impromptu audience. Originally added for the benefit of the performer, it was later recognized that the addition of laughter increased the audience's en? joyment of a performance. Television comedies from the early 1950s until the present often have had laugh tracks added to their broadcasts even when they were "recorded before a live audi? ence." Laugh tracks do indeed increase audience laughter and the audience's rating of the hu morousness of the comedy material. Here Ed Wynn (right) and Leon Errol act up in a skit from the televised Ed Wynn Show in the early 1950s. such a laugh detection and releasing process. Future psychophysical studies must determine which of laughter's pa? rameters?note structure, note dura? tion, internote interval and amplitude dynamics?are necessary for the per? ception of laughter and the activation of the hypothetical laugh detector or re? leasing mechanism. Similar detectors may have evolved for universal phone? mic features of speech but the variabili? ty and complexity of language and the absence of a contagious response to as? say the activation of the detectors will make their discovery more difficult. Future Directions Now that the critical dimensions of laughter as a social stimulus and motor act have been identified, we can pursue a variety of promising issues. Consider "pathological laughter," a frequent and
"laughing gas" and other drugs known to increase laughter simply lower the threshold for laughter, or do they alter its pattern or quality? In aphasia (a dis? order of language production or percep? tion) is there sparing of laughter and, if so, which of laughter's several dimen? sions are spared? Does vocal laughter punctuate the signed speech of the con genitally deaf, in whom there is not a shared organ of expression? The left cerebral hemisphere has a specialized role in language?is this also true of the production or perception of laughter? Many developmental issues remain open. Laughter typically appears in hu? man babies around 3-1 /2 to 4 months of age, but we know little about the details of the developmental process. Must ba? bies hear their own laughter or the laughter of others for laughter to ma? ture? If so, is there a critical period dur? ing which such laughter must be experi? enced? The report of laughter in a few congenitally deaf-blind children suggests that at least some features of laughter de? velop without benefit of auditory and vi? sual stimulation, evidence of a strong maturational and genetic basis. For a more satisfying account of laugh acquisi? tion, we must conduct high-resolution studies that contrast the development of normal and hearing-impaired children. All of us have encountered people with bizarre-sounding laughter. What is different about such laughter and what does this tell us about the mechanism of normal laugh production? Do these odd types of laughter run in families? If so, what is the nature of its develop? ment and heritability? In my otherwise forgettable high-school physics class there was a kid who brayed like a don? key when he laughed. Where is Roger now that I need him? Comparative studies may provide clues about both the evolution and so? cial function of laughter. 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 vo? calizations? Do the great apes show the sexually dimorphic or contagious laughter described in human beings? Does the pattern of laughter vary with rank within a troop? Aside from the great apes, do other animals produce laugh-like vocalizations? How do the neurobehavioral mechanisms of laugh production vary between species? Tick? le may be a kind of Rosetta Stone for such comparative laugh research b