THE UNIVERSALITY OF HUMOR AND LAUGHTER
Humor and laughter are a universal aspect of human experience, occurring in all cultures and virtually all individuals throughout the world (Apte, 1985; Lefcourt, 2001). Laughter is a distinctive, stereotyped pattern of vocalization that is easily recognized and quite unmistakable (Provine and Yong, 1991). Although different cultures have their own norms concerning the suitable subject matter of humor and the types of situations in which laughter is considered appropriate, the sounds of laughter are indistinguishable from one culture to another. Developmentally, laughter is one of the first social vocalizations (after crying) emitted by human infants (McGhee, 1979).
Infants begin to laugh in response to the actions of other people at about four months of age, and cases of gelastic (i.e., laughter-producing) epilepsy in newborns indicate that the brain mechanisms for laughter are already present at birth (Sher and Brown, 1976). The innateness of laughter is further demonstrated by the fact that even children born deaf and blind have been reported to laugh appropriately without ever having perceived the laughter of others (Provine, 2000). Indeed, there is evidence of specialized brain circuits for humor and laughter in humans, which researchers are beginning to identify by means of neural imaging studies. Thus, being able to enjoy humor and express it through laughter seems to be an essential part of what it means to be human.
Interestingly, though, humans are not the only animal that laughs. Primatologists have studied in some detail a form of laughter emitted by young chimpanzees, which was first described by Charles Darwin (1872). Similar types of laughter have also been observed in other apes, including bonobos, orangutans, and gorillas (Preuschoft and van Hooff, 1997; van Hooff and Preuschoft, 2003). Ape laughter is described as a staccato,
throaty, panting vocalization that accompanies the relaxed open-mouth or "play face," and is emitted during playful rough-and-tumble social activities such as wrestling, tickling, and chasing games (see Figure 1). Although it sounds somewhat different from human laughter, it is quite recognizable as such, occurring in similar social contexts as laughter in human infants and young children. Indeed, there is good reason to believe that human and chimpanzee laughter have the same evolutionary origins and many of the same functions.
In addition to laughter, there is evidence that apes may even have the capacity for a rudimentary sense of humor. Chimpanzees and gorillas that have been taught to communicate by means of sign language have been observed to use language in playful ways that are very reminiscent of humor, such as punning, humorous insults, and incongruous word use (Gamble, 2001). Interestingly, these humorous uses of linguistic signs are sometimes also accompanied by laughter and the play face, indicating a close link between humor, play, and laughter even in apes.
All of these lines of evidence suggest that humor and laughter in humans are a product of natural selection (Gervais and Wilson, 2005). Laughter appears to have originated in social play and to be derived from primate play signals. It is viewed by evolutionary researchers as part of the nonverbal "gesture-call" system, which has a long evolutionary history, predating the development of language (Burling, 1993).
With the evolution of greater intellectual and linguistic abilities, humans have adapted the laughter-generating play activities of their primate ancestors to the mental play with words and ideas that we now call humor (Caron, 2002). Thus, although they usually do not chase and tickle one another in rough-and-tumble play, human adults, by means of humor, continue to engage in frequent social play. These evolutionary origins of humor and laughter suggest that they likely have important social emotional functions that have contributed to our survival as a species. Although humor has a biological basis rooted in our genes, it is also evident that cultural norms and learning play an important role in determining how it is used in social interactions, and what topics are considered appropriate for it. In addition, although all forms of humor seem to originate in a basic play structure, the complexity of human language and imagination enables us to create humor in a seemingly endless variety of forms.
As human language, culture, and technology have evolved, we have developed new methods and styles of communicating it, from spontaneous interpersonal joking and banter to oral storytelling traditions, comedic drama and humorous literature, comedy films, radio and television shows, and jokes and cartoons disseminated over the Internet. Besides being a form of playful fun and entertainment, humor has taken on a wide range of social functions over the course of human biological and cultural evolution. Many of these interpersonal functions are contradictory and paradoxical. Humor can be a method of enhancing social cohesion within an in-group, but it can also be a way of excluding individuals from an out-group. It can be a means of reducing but also reinforcing status differences among people, expressing agreement and sociability but also disagreement and aggression, facilitating cooperation as well as resistance, and strengthening solidarity and connectedness or undermining power and status. Thus, while originating in social play, humor has evolved in humans as a universal mode of communication and social influence with a variety of functions.
WHAT IS HUMOR?
The Oxford English Dictionary defines humor as "that quality of action, speech, or writing which excites amusement; oddity, jocularity, facetiousness, comicality, fun." It goes on to say that humor is also "the faculty of perceiving what is ludicrous or amusing, or of expressing it in speech, writing, or other composition; jocose imagination or treatment of a subject" (Simpson and Weiner, 1989, p. 486). It is evident from these definitions that humor is a broad term that refers to anything that people say or do that is perceived as funny and tends to make others laugh, as well as the mental processes that go into both creating and perceiving such an amusing stimulus, and also the affective response involved in the enjoyment of it. From a psychological perspective, the humor process can be divided into four essential components: (1) a social context, (2) a cognitive-perceptual process, (3) an emotional response, and (4) the vocal-behavioral expression of laughter.
