Clap, Clap, Clap - Unsystematic Review Essay on Clapping and Applause

Abstract

The rationale for the following unsystematic review article is to provide a dense description of clapping behavior from an ethological, psychological, anthropological, sociological, ontological, and even physiological perspective. The article delves into its historical uses, possible biological-ethological evolution, and primitive and cultural polysemic-multipurpose social functions. It explores the different distal and immediate messages transmitted by the simple act of clapping, to its more complex attributes like synchronicity, social contagion, as a device of social status signaling, soft biometric data, and its, till now, mysterious subjective experience. The subtle distinction between clapping and applause will be explored. A list of primary social functions will be introduced based on the literature on clapping. In addition, a series of unresolved questions and possible research avenues will be suggested. In contrast, out of the scope of the essay and published as a second article will be the contents of clapping morphological variations and a comprehensive description of purposes achieved through them.

Introduction

Few researchers have developed scientific explorations and hypotheses about the origin, function, and intention of clapping and applauding. However, even so, today, many unresolved questions and gaps in knowledge are sufficiently evident to argue that applause behavior is understudied. There is no chapter dedicated entirely to this behavior. Articles tend to address one aspect, such as its relationship to diseases such as Parkinson's (Abdo et al., 2007) or frontotemporal lobar degeneration (Schönecker et al., 2019), synchrony (Néda et al., 2000), development (Fitzpatrick et al., 1996), as a relevant behavior in political speeches (Bull & Noordhuizen, 2000), or as acoustic identity (Wróbel & Zielińsk, 2021), but no review has been published yet.

Moreover, due to its complexity, usefulness, and ubiquity in social contexts and cultures, interest in the applause could extend to political scientists, historians, sociologists, musicologists, psychologists (Repp, 1987), ethologists, and every curious human observer.

Definition

The first obstacle in studying clapping is its definition. Unfortunately, the unsystematic review of the literature shows that each author defines clap or applause differently, sometimes not even presenting this necessary distinction, and even on occasions using definitions not on dictionaries but rather on their subjective perspective in which the research will be done. As such, it is argued that semiotics, human ethology, and nonverbal communication research need a formal definition; an operationalization of clap and applause.

So, within Western culture, the word "clap" is the socially accepted signifier that describes beating the palms against each other, often rhythmically – but not always - to produce a sound. First, however, let us inspect what a dictionary has to say. The Merriam-Webster online English Dictionary refers to it as a verb with at least five meanings: 1) "to strike (two things, such as two flat, hard surfaces) together to produce a sharp percussive noise," 2) "to strike (the hands) together repeatedly usually in applause, 3) to strike with the flat of the hand in a friendly way", 4) "to place, put, or set especially energetically, and 5) "to improvise or build hastily."

Here it will be argued that to comprehend the action, it is essential first to decompose the building blocks of clapping so as to highlight the common aspects between definitions. Let's get into its components one by one.

First, it is commonly accepted as an action, usually involving coordinated movement. Secondly, three definitions emphasize the presence of a blow between hands, between things, or between hand and body. Clapping can be done not only between hands but between parts of the body or between objects, but here in the article, hand-to-hand clapping will be our focus, and it is out of reach the different ways in which people can clap their own body as well as of the other person.

Third, a sound results from the clash of the action, which the two most frequent definitions highlight. While the social purpose of clapping may change due to almost infinite factors, the mechanic purpose of the action may be the acoustic generation of a prototypical human sound: the clap sound. Not surprisingly, the word clap is an onomatopoeia in itself. How many words are equal to the sound their produce? It is indeed one of the few.

Fourth, two secondary definitions imply that clapping conveys either a friendly message or doing something energetically. Both meanings could convey a nonverbal attitude of non-menace and affiliation.

Fifth, and last but of vast importance, repeatedly hand striking – aka. clapping –is usually conceived as "applause," but not always. It makes the case that applauses are at least in part claps, but claps are not necessary applauses. So, clapping and applauding may not be the same, even if they are sometimes used interchangeably.

The definition of the same dictionary on applause is "to express approval especially by clapping the hands." In this definition, ‘applause’ makes the case that it may be done with claps, but it could also be conveyed through other verbal and nonverbal channels (e.g., saying "I applaud you"). The core of the meaning of the word "applause" is the behavior’s purpose: expressing approval. So, while clapping could convey multiple meanings, applause is reserved for claps that send messages such as praise. Clap has no intrinsic meaning, and applause has one.

An equally significant aspect is the way the Royal Spanish Academy conceives the word applause, which derives from the Latin "applausus" and "applaudĕre1." It alludes to the rhythmic repetition of behavior with the symbolic goal of expressing approval and enthusiasm, agreeing with Merriam-Webster's previous definition.

In order to clarify the matter, the primary two differences between clap and applause will be presented: 1) applauses are always considered a series of multiple claps; instead, claps are, in essence, individual behavior but frequently performed in a sequence2, and 2) secondly, on one hand, applause is generally related to its function as approval signal, on the other hand, clapping is a more descriptive way of referring to behavioral action with no particular social message.

In this essay, clap and applause were initially considered as synonyms since the article was originally written in Spanish, in which the word clap is translated as "palmada", which is rarely used in comparison to the word "aplauso" (applause), which is generally interchangeably used to refer to clap or applause, to express approval, convey respect to the national flag or clapping to the sound of music, but in the end, this differentiation is crucial for a better understanding3.

The formal definition proposed here is this:

Clapping is a universal bodily action performed consciously whereby the two primary movements are 1) the lateral inward movement of the forearms in the transversal axis – generally - towards the center of the sagittal axis and 2) the collusion between left and right open hands against each other in a prototypical frequent position, with several variations in hand, arm and posture options, that produces from the blow an acoustic human widely recognizable sound. The mechanical objective of such action is to compress and explode a small air bubble between the palms (Connor, 2003). It is done with a subsequent constant repetition of the same action in most cases, following a relatively stable rhythm with a tendency to increase or decrease the amounts of claps per minute. One more thing is that claps are most generally performed with the intent to communicate something.

A fundamental quality of clapping is the emission of a non-verbal audible message through the audible channel and as a byproduct of applause. As developed later, the junction between movement and sound makes up the complete behavior, and the absence of one of them will modify the reception of the communicative message. There is no sound of clapping without a blow. Besides its kinesics properties, a central characteristic, possibly the reason for the widespread cross-cultural usage, is that it is perhaps the most common audible activity of humans performed to be heard by others that do not involve the vocal tract (Repp, 1987) and may be the loudest.

Even if some researchers consider the claps or applauses as a behavior of an emotional response to semiotic stimuli (Richardson, 2021), this essay argues that it is a misconception to circumscribe such complex behavior to a specific category of inner states, being emotion, cognition, or attitudes. Other conceptions, like Atkinson (1984), that "one person may clap their hands, but it only becomes applause when several do so repeatedly and at the same time" (p. 21) may cloud this behavior rather than help. Defining clapping and applause based on the number of performers seems an unnecessary taxonomy. Instead, evaluating its purpose or execution may be of much more help to discriminate these two words, as it will be shown.

Is a Clap a Gesture?

As such, clapping behaviors face the traditional obstacle: every taxonomy is nothing more (and nothing less) than a helpful temporal device selected based on the researcher's perspective. As a result, neither taxonomy is universal (Kendon, 2004) nor an omnicompetent tool; instead, they are used based on the needs and preferences of the researcher.

Visible non-verbal behaviors - kinesics - could be organized into one of three options, gestures, manners, or postures (Poyatos, 2010). The first is more dynamic and fleeting, conscious or unconscious, body movement used as a primary communicative tool (while exceptions). The second, manners, is an underused classification that brings light to the often dark and rarely differentiated horizon between what seems a gesture and not, and what seems a posture and is not. It refers to more or less dynamic body attitudes (e.g., walking, the way someone eats or drinks). Finally, the third one, postures, are more extended and static positions adopted by the body or some of its parts for a prolonged time with less communicative intention. Sometimes frontiers between categories are blurred so that behavior may be simultaneously in two or more categories, which in the case of clapping, it may be so. Let us see some examples.

The complexity of classifying the applause lies in taxonomizing. For example, a clap may be simply a co-verbal gesture (while chanting), an emblematic gesture (to convey approval after a theater play), and a regulator of interaction at another time (to indicate that a ceremony is beginning). Maybe in a different context, it could be seen as a behavioral instrumental gesture (while dancing), sometimes as a deictic gesture ("hey, I am over here"), or as a manner (clapping as an activity).

Evidently, as a non-verbal act, clapping can be interchangeably classified into different categories based not only on the operationalization of the researcher but also on the purpose of the clap at the moment of execution. For instance, a pat on the back could be used as an adaptor to communicate approval, while at another time, the same pat could be to request the turn of dialogue, which would be considered a regulator.

Evidently, the claps could be classified differently based on the purpose they fulfill. This is, the article argues, and as Kendon criticizes it in his book of 2004, one of the problems with the most popular taxonomy in the research of nonverbal communication from Ekman and Friesen (1969). Today is one of the most cited articles in the field of visible nonverbal behavior (Plusquellec & Denault, 2018).

Here, to illustrate how the mentioned taxonomy works, applause and clapping are classified based on the functions fulfilled at the moment of execution. For example, applause could be considered an emblematic visual gesture, which means a behavior that has a meaning capable of being translated into a word or phrase, known by members of the same culture, and performed with full consciousness. In fact, in a text, the word "applause" can function as a linguistic emblem, indicating the presence of approval, but a "clap" may not convey it. So, a clap in and of itself can have multiple purposes, so it will be incorrect to consider it an emblem in every case.

Emblems have a prototypic mode of execution concerning the place of presentation (in the case of applause, maybe there is a prototypic latency between sounds that help recognize the characteristic rhythmical sound) and a specific intensity (not necessarily), which facilitates their recognition. Clapping, like laughter which is not an emblem and has much more flexibility in being capable of sending multiple messages, is very susceptible to individual variations; nevertheless, the intended signal of clapping in several contexts creates a usually consensual signal of approval and is still clearly decoded as an emblem, as generally laughter is understood as a positive behavior but polysemic and not limited to a cultural meaning or a verbal translation. So, while applause may be considered an emblem, clapping may seem it is not.

Claps could likewise be considered in a different category, the last of the five, adaptors. In this category, it would fit as an audible self-adaptor (Poyatos, 2017a). They are movements in which one part of the body comes into contact with another and produces a sound (Poyatos, 1988).

Another option is to consider claps as regulator devices that signal the beginning or end of certain events like a musical or political rally; they could indicate the start of a race or call out the attention of a class of talking-interrupting students. Maybe in neither of the last cases, those claps relate to approval, but sometimes, claps can be both at the same time an emblem (as applause) and a regulator. For instance, to acknowledge the welcoming of the national flag.

Due to the multiplicity of functions that claps can fulfill and the different morphologies, this article argues that the most descriptive and least interpretative classification fits better to study such complex behavior. Therefore, the clap will be considered a phonokinesic non-verbal manner, a compound visual behavior that produces a particular sound with no specific meaning but has ample polysemic potential. Clapping is a complex behavior composed of several movements and positions of the body performed to produce a bursting sound at coordinated intervals. Although acts such as walking or jumping seem to fall in the domain of 'manners,' these behaviors are non-interactive, and task-performing actions are challenging to categorize. Manners describe a bodily attitude whose corresponding meaning is socially codified concerning the specific situation (Poyatos, 2013). Moreover, clapping, just like walking or swimming, involves a repetitive set of coordinated and repetitive sequences of timed behaviors. In contrast, applause is best suited to be considered an emblematic nonverbal behavior with cross-culturally shared meanings of approval, praise, and support.

In non-verbal communication, it is challenging to establish a dictionary of behaviors, if not impossible, since, by basic principle, any behavior can have several meanings, and different meanings can have several associated behaviors (Burgoon et al., 2021). Maybe it is better to think about inventories or human ethograms. It is, therefore difficult to give a single meaning to a bodily action because the cause of it will never be known with absolute certainty, and such attempts to correlate a meaning with behavior have proven to be quite unfortunate. In addition, an endless number of moderating variables (aka. factors of influence; see Patterson & Quadflieg, 2016), such as the environment, culture, personality, gender, and even the idiosyncrasy of the person who will carry it out, will modify the execution, function, and meaning of every nonverbal behavior. Clapping does not escape these factors of influence.

In summary, clapping is a behavior with multiple variations in the range of potential messages and behavioral forms of doing it, while applause is an emblematic behavior with a circumscribed horizon of positive supportive and approval meanings. Types of messages sent through claps possibly depend on behavioral differences. In other words, claps could be performed in different ways and with different intended purposes and meanings, and as such, the messages sent polysemic and multipurpose non-verbal signs (Givens & White, 2021). The multiple variations are out of the scope of the essay, and here, its evolutionary and ontogenetical history will be explored.

Evolutionary Origin of Clapping

Hypothetically speaking, clapping behavior was a communicational vehicle when primates' ancestors lacked vocal apparatuses suitable for producing spoken language at a given moment in evolution. At the same time, they did have the muscles and motor and structural capabilities indispensable to produce claps.

Considering that clapping is a manifestation of shared communication with other primates (Kalan & Rainey, 2009), chances are that humans have inherited this behavior from a primate predecessor. In the evolutionary plane, there is a clear inflection point of the manual action of the arms when ancestors replaced the crowns of tall trees for the plains of the savannah, and as a result of a long evolutionary process, they freed their upper limbs from quadruped walking. It would not be inadmissible to think that only here, once the hands freed from supporting the body, they could execute more complex movements, previously unthinkable.

What situations would evoke applause in pre-homo sapiens times? Perhaps, to signal the physical presence of a predator or advert a relevant event to our peers by drawing attention to a possible threat, as the wild gorillas of the west do (Kalan & Rainey, 2009), or signaling a potential opportunity. Other options, with no exhaustivity, could be a loud sound and a blow to visually and audibly intimidate an opponent (threaten), to invite other congeners to engage in a playful interaction (affiliative game), or to promote social interaction in group situations or cooperation between individuals of the same species (act as devices that promote group synchrony like yawning).

All of the above are plausible speculations since clapping is par excellence, the non-vocal signal with the highest acoustic volume, and a source of an efficient volume projection capacity. This is a simple, quick, and effective action. However, because of this, its true origin becomes blurred and questionable. Nevertheless, it leaves room for the reader to deduce and produce his conclusions until there is no doubt about the true origin. Hopefully, science will answer, but in the meantime, "imperfect knowledge is better than none in navigating the waters of our social world" (Burgoon et al., 2010, p.24). In this case, it is better to have a theory to comprehend a widely cross-cultural frequently used behavior instead of not having one.

An interesting evolutionary theory about the clap's origin is that of Steven Connor (2003). The author suggests that "clapping can be understood as a specialization of the action of the hand strike, which is a distinctive achievement of primates" (p.67). Clapping, he says, must be a variant resulting from slapping one's own body, which is often accompanied by jumping and striking, typical behaviors of primates in states of excitement. Clapping was, for the author, a more controllable and consistent alternative, more helpful in producing body sounds than slapping the palm against the chest or other body parts.

The specific abrupt sound of clapping seems to involve the startle reflex of the listener's midbrain (Givens & White, 2021), turning it into a valuable signal to redirect the attention of others. In addition, some apes use audible gestures, such as clapping, to communicate with their peers intentionally, especially when their companions look in a direction other than the sender desires (Call & Tomasello, 2007). Such evidence points to considering clap sound as significant stimuli that attract the brain's attention as they may hold survival or adaptive value.

Claps, besides creating a more powerful sound than a self-administered slap to any part of the body, possibly had the purpose of producing not only noise but to make a visual-audible exhibition of body size, strength, and musculature. Perhaps, it fulfilled a function similar to that achieved by blows to the chest of gorillas, in which the sound produced by the blows may reveal aspects of fitness or honest signal of body size (Wright et al., 2021).

The most current example of this theory of slapping parts of the body as a visual and acoustic display of fitness or dominance is the Maori dance or "haka." In their coordinated dance, performers clash their hands with several different parts of their bodies. The ritual has at least two opposite meanings based on the context of usage; it can be a hospitality greeting reception dance or a method of intimidation prior to a confrontation with an opponent. For example, when players of the New Zealand rugby national team performed this coordinated activity before a match in front of rivals to intimidate and demonstrate intergroup unity. With the dance, they manage, in addition to quail their opponents, activate the body muscles with the repeated self-administered hits that stimulate their muscles, exhibit group coordination as a cue of group skill, and increase synchrony of group feelings and states.

If Connors's theory is correct, it would seem unexpected that one of the most pancultural behaviors used to recognize the merit and approval of others (applause) has its origin in a violent or dominant exhibition of self-blow. It could mean that clapping as a polysemic behavior has created many different paths for different usages and functions.

In contrast to the aggressive-hostile theory, if the clap's social function were related to playfulness-affiliation, it would suggest a positive valence function and be more in line with it. The ethologist Morris (1972) suggested an alternative theory about this. The act of patting one hand against the other to express approval possibly stems from patting someone's back to congratulate them. The actor or athlete opens his arms as a sign of inviting others to hug him and put his arms and hands behind and around his back respectively, but, since the spectators cannot do it, they perform the clapping as a substitute signal for patting on the back. Maybe it’s a way to recreate the sound that patting the back of the person would produce. This same observation of the applause as a kind of embrace seems to have been previously mentioned by James (1890) in a comment on F.G. J. Henle's Anthropologische Vorträge (1876-80). So, in those instances, clapping action becomes applause when it is symbolically used as a non-physical distance haptic behavior that at distances simulates, somehow metaphorically, that one embraces another.

Based on the theories proposed, claps possibly have three distinctive primitive basic functions and one modern one.

The distal functions fulfilled by clapping in ancient times could be one or more of the next: 1) deictic (attracting or redirecting attention), 2) an indicator of playful invitation, or 3) a visual and acoustic threat. Nevertheless, these three distant functions logically are accomplished at least slightly with applauses, as used in the 21st century during most social situations. So, potentially, the message of approval of the applause is the proximal function of modern applause but not of clapping.

It means, then, following the intellectual trajectory of Morris (1977), the applause of approval (or recognition) is a gesture historically displaced from its original biological function (e.g., attracting attention, playing effusively, or threatening) to convey support, approval, or recognition. While clapping is a multipurpose and polysemic behavior with much more communicative flexibility, applause is reserved for communicating positive messages about support, approval, recognition, respect, and congratulations.

Development of Clapping During Ontogeny

Is it an innate behavior? What is the primary function of clapping? So old is the origin of the behavior that it is not unique to our species since we share this behavior with other species of primates (Kalan & Rainey, 2009) and mammals, such as gray seals (Hocking et al., 2020).

David Matsumoto observed judo athletes participating in the 2004 Olympics and Paralympics, on sighted and blind from birth, with the primary purpose of corroborating the hypothesis that there are facial expressions of emotions universal and congenital in all human beings, and this is how he confirmed that there are - at least some - universal facial expressions (Matsumoto & Willingham, 2009). The debate considering the universality and prototypicality of facial expressions is out of scope4.

By adopting this naturalistic approach of contrasting sighted and non-sighted individuals applied to the kinesics expression, evidence shows that clapping behavior is identical in the sighted and the blind. Still, it does differ when observing the applause in the deaf or deaf-mute. These last two groups of individuals, to express approval, do not "clap" but instead perform a silent clap: they raise their arms and hands above their heads and wave them in a horizontal direction5.

They created an emblematic applause waving hands in the air. The main reason seems to be that these individuals valued movement over sound for apparent reasons; furthermore, this signal is conspicuous enough not to be missed. For instance, clapping can be done under the table, or other people can obstruct visibility, impeding hearing-disabled people from recognizing the message of claps and applauses. The subjects with helplessness or dysfunction in auditory senses while performing this symbolic applause do not produce any sound and even modify its basic form and the habitual position of executing them, making another case to classify applauses as emblems. It could be argued that this behavior is not a clap or applause but a symbolic replacement of the hand clap and should not be considered a hand clap. As a result, this 'clapping' behavior seems learned and different from the 'normal' clapping. Nevertheless, even with such modifications, it’s appropriate to consider this an "applause" that transmits the same positive message through a different action.

The previous discovery raises a critical question: possibly clapping is not an innate behavior but an acquired one during development; being that the case, when and how do humans learn to applaud? But even more poignant, do were learn to clap, or is it a biological legacy? Possibly humans learn first to clap, and only after the development of specific cognitive skills can they use the clap as applause.

If clapping is acquired during ontogeny, it must have an origin accessible to all humanity and be easy to learn to explain its worldwide distribution. Homo sapiens have developed a series of universal behavioral patterns, such as laughing, yawning, and smiling, present in the more heterogeneous cultures, all of which have an overarching repertoire of different meanings they can convey. Nevertheless, they tend to occur cross-culturally more frequently, related to a limited set of situations and meanings. Could clapping be considered a behavior in this same category?

Clapping behavior can arise before the spoken word or language appears. Piaget (1977) proposes that, during the first period of life, from birth to around two years, the infant develops an innate motor intelligence for survival. During this period, circular reactions appear as repetitive physical movements. Theoretically, humans could only be able to learn to coordinate claps during the third substage of the sensory-motor (between 4 to 8 months old). During it, hand-eye coordination begins to crystallize. It is perhaps the period that allows individuals access to bodily behaviors more complex than the reflexes with which humans are born.

In experimental studies (Fitzpatrick et al., 1996), children learned to clap late during the first year of life. However, they have not yet developed the necessary coordination to produce a stable and predictable sequence of body actions (or sound), characteristic of the synchrony of the upper limbs of clapping, despite having the ability to coordinate motor skills to fulfill other tasks. The last discovery suggests that clapping is considerably more challenging to learn than other basic body activities. Furthermore, the same study found that optimal motor control necessary to produce a consistent clapping pattern appears to be available only from age seven, progressing from close coordination to complete coordination. So, it takes humans so long to master the art of clapping? More study is needed here.

The researcher who can provide enlightening information on the ontogenetic acquisition of clapping is Desmond Morris. He studied human behavior while traveling in more than 60 countries for eight years. As a result of his research, among other conceptualizations, he established five categories by which homo sapiens incorporate actions into their motor repertoire (Morris, 1977). Every action's origin could be classified as hereditary, absorbed, discovered, practiced, or a mixture.

By discarding some of these options, two things emerge as relevant; applause seems not to be an innate (hereditary) action that is rooted in the genes as a phenotypic expression.

Whether the behavioral origin responds to imitation (absorbed) from the behaviors of others is possible, but it probably would not explain the cross-cultural widespread and universality of the action. However, the infant who receives applause or observes this action in his peers will probably be more likely to replicate this behavior. This may guide his actions and promote replicating the behavior in the future. Due to the low level of difficulty that clapping requires (but more complicated rhythmicity), it is doubtful that any training (practiced) is required to accomplish a simple clap (not an optimal one) but rather a flash of spontaneity or imitation of another, in contrast to finger snapping. Nevertheless, practice will be needed to produce a robust and constant blow-off sound with a high amplitude. It is easy to hit the palms, but producing the 'correct' sound is considerably more complex.

Finally, the applause could be an action that humans discover individually by themselves, unconsciously acquired in the process of self-knowledge of the body, which, in this case, because it is a simple byproduct of coordinating movements of the hands possibly incorporated at an early age (more accessible than winking). In other words, clapping seems to be a discovered action while exploring the kinesic possibilities offered by the anatomical body. It is only then that culture and learning influence the execution by imitation.

Poyatos (1988) notes that the child's body examination gradually becomes more selective and determines the use of behaviors such as finger drumming. So it is that during early development, kids discover a wide range of motor possibilities based on the biological structure, and it is thus that, as part of the maturation process, they can find certain behaviors on their own, including clashing open palms to each other to get the attention of other humans.

Probably claps origin is one of mixed history during development, a combination of discovery, absorption, and practice. Discovery may be the primary origin; absorption may be the secondary influence, and training in time will carve the specific style in which a person applauds and the resulting acoustic sign.

Clapp as an Expression of Soft Biometric Data

Clapping, like vocalizations, offers a distinctive type of information: in an instance, both activities reveal cues about the configuration of specific articulations during a given moment. For this same reason, albeit slight variations occur in these mobile joints, acoustic consequences will occur (Repp, 1987). According to this explanation, Repp concludes that, just as the vocalizations of the animals have been keys related to body size, maybe claps offer information about the size and shape of the hand (an indirect signal of physical strength) and even the type of execution (type of social message). Different morphological anatomies and dynamic positions of fingers, hands, and arms must limit and condition the action and characteristic volume. In this study, first, participants could recognize with some accuracy claps produced by different configurations of the hands. Second, the spectrograms appear to have detected the presence of an acoustic "signature" in each individual's clapping, suggesting the idea that, at least partially, each participant clapped with an idiosyncratic sound spectrum. Finally, while the participants had difficulty recognizing the identities of other participants, they appeared to be adept at detecting their own just by clapping sounds. Two studies conducted identity recognition with 16 participants. Jylhä et al. (2012) found that a 64% recognition could be achieved with an algorithm trained to detect spectral changes in sound. A recent study (Wróbel & Zielinski, 2021) that included claps in three different scenarios (living room, kitchen, and bedroom) supports this idea after finding that an algorithm could be trained to automatically recognize the identity of 16 individuals based on the idiosyncratic sound of their claps.

Clap as an Expression of Language and Inner Thought

In line with the theory of human expression (Bühler, 1933), bodily expressions have been less studied than the language dimension, as is the case with clapping. Clapping and, most frequently applause as interpersonal expressions are commonly seen as a materialization of an inner thought that expresses positive recognition, but not necessarily. Using the body, specifically arms and hands, the body reflects the performer’s subjectivity (Fossa et al., 2022). In this way, thoughts become visible – and non-vocally audible – by external manifestation through body movement (Werner & Kaplan, 1963). In some cases, the body may materialize the meaning before the mediation of words in the mind, meaning that behaviors like clapping may appear before the mental representation of words (Fossa et al., 2022) like “approval” or “recognition”. While productive for future research, the physiognomic-organistic perspective of clapping and its relationship to language and inner thought it’s out of the scope of this review since no article has pursued this relationship yet and may well be an avenue for researchers.

Clap as a Social Act

When did clapping first originate as a shared social act? Bella Itking6 proposed a plausible and sustainable argument theory. He considers that clapping founded its genesis in primitive times, in front of a bonfire in ancient rituals where individuals manifested satisfaction and celebration through different bodies and artificial tapping, even applauses. Maybe he is right. There is no way to know for sure. There is evidence that collective rituals may promote physiological synchronization (Konvalinka et al., 2011), and the act of clapping may contribute to a sustained rhythm and regularity. Connor (2003) would add, complementing this argument, that clapping was the source of the first systematic music produced by humans. To this, some suggest that the process of engaging in various activities related to music – like clapping - fosters a feeling of interpersonal connection and intimacy among individuals within a collective setting (Weinstein et al., 2016).

Reports of indigenous ceremonies, such as that of the natives of North Carolina, indicate the use of claps, among other behaviors, such as striking the foot with the floor and raising the arms (Carayon, 2019), with the belief that it had magical properties. More data is needed regarding the function and meaning of applause in tribes. For example, Morris devised that Mbuti pygmy sometimes, instead of using both hands, clap one hand against the naked sin of the chest, which anatomically has a visual similarity with a gorilla's chest-beating7.

The first recorded evidence of social clapping, according to Jenniches (1969), dates from ancient Greece in the 5th century B.C., used by spectators as a group differentiation, possibly fulfilling the function of separating the role of the actors from the spectators (Kowal, 2009). Maybe, in time, clapping propagated to multiple scenarios. Today the clapping and applauding happen daily at thousands of events, from birthdays to political events. Nevertheless, is the function of the action the same in every situation? Most surely not.

The importance of applause as a sign of approval or recognition is ancient. According to some accounts, Emperor Nero paid up to 5,000 knights and soldiers, known as the Augustiani, to cheer his public appearances with applauses (Mouratidis, 1985). Over time, theater managers and business people found they could do the same at their events, hiring people to clap (also called claqué). In the XX century, television and the media found that they could replicate this strategy as it happens with canned laughter (Provine, 2000), but in this case, with canned applause (Kowal, 2009). Using such a strategy gives the impression that the audience agrees with the presenter, and politicians provide the appearance that more people attended their events.

The significant difference between laughter and clapping is that the second is a manual articulatory behavior of longer duration (because it does not require breathing) and with a more significant initiation latency (Atkinson, 1984). Therefore, it begins slower and tends to last longer. The other noticeable difference between laughter and clapping is the sound origin: laughter results from several inner muscles, predominantly those related to breathing. In contrast, clapping requires external motor coordination and produces a sound without involving the vocal tract.

Another joint social function of collective clapping is typical when a soccer team enters the field, as the public receives the players through chants, rumbling, and claps. In this situation, those coordinated claps accomplish two simultaneous purposes: to express support for their club of belonging and, on the other, to cow the rival team. Another type of clapping common in stadiums is synchronized clapping, which occurs in situations where one would not ordinarily clap. It sounds completely different from traditional clapping because its rhythm is usually slower, highly synchronized, and performed with the hands above the head (Morris, 1981). According to Morris, it appears to be an invention of English origin.

Going back in time, Heraclitus was the first to discover the previous strategy of intimidation by sound clapping. During the weakened period of his rule, the emperor of the Roman super-tribe planned a meeting between himself and the barbarian king. The first of them hired men to applaud upon receiving their counterparts to impress and intimidate their opponents, possibly the oldest example of clapping as an intimidation strategy (Megan Garber, The Atlantic)8.

Another historically relevant social context in which claps have played an appropriate role is that of religious celebrations. According to Kowal (2009), applause was more frequent at the beginning of the church’s history before it was considered a pagan practice. Only later, after the Second Vatican Council, did it return acceptably. Through claps, admiration, support, approval, praise, and joy have been expressed (Poyatos, 2017b). According to Poyatos's records, John Paul II elicited applause in his homilies, in the entrance and exit processions preceding Holy Mass, and at his funeral. Some more examples of applauses functions are as a sign of "celebration" after choosing a candidate for ordination, in the taking over of a priest or bishop, or after the bride and groom consent to marriage. All the above are social rituals indicating a relevant change in the status of the receiving individual that merits approval from applauders: a new professional position or relationship status associated.

A more recent study done with polish families (Remisiewicz & Rancew-Sikora, 2022) has highlighted how moments of applause accomplish a particular function besides directing attention or showing appreciation. They found it is used as a ritual anchor that allows the participants to move to the following ritual sequence. So, applauses may work as transitional stages in social rituals regulating the flow of the situation. Something similar happens after audiences in stadiums and events finish singing the hymn or closing events, clapping and applauding to indicate a group's transition in the public event. The same has been found true when applauding after commemorating the holocaust; even after the audience was instructed not to applaud, the impulse was so strong that it happened at least five times (Richardson, 2021).

Modern naturalistic observations in debates or competitions show how claps and applause may well be used to offer support to a person, group, or proposal. Possibly, the same function could have been used in the past in tribes, competitions, etc. For example, the audience may choose to applaud more intensely towards one participant in a T.V. contest as a nonverbal expression of support so that the participant may advance to the next stage or win the event. During the COVID-19 pandemic, at least in Argentina, the U.K. (Mackay, 2021), Spain (Zlobina & Dávila, 2022), and France (Novello Paglianti, 2020), people clap publicly at the socially accorded hour of the day to express support and thanks health professionals for their efforts.

Hypothetically, clapping may have unconsciously played an active role influenced by social exchanges as a secondary communicational tool. Why scream if humans can clap? It is suggested that people can resort to clapping in certain situations where verbal language or vocalic expressions seem to be an unusable, ineffective, or excessively disturbing channel. For example, in mass events, it is effective as a tool to communicate over long distances. Usually, in Argentina, when a child is lost on the beach or in malls, people around him use synchronous clapping to attract attention so that parents can find the child. Another example, perhaps more common in the twentieth century before the invention of the cell phone, occurred in the absence of a functioning doorbell at the door of homes. People clapped for the subjects inside to listen. In this previous situation, the clap functioned as a more cordial and less disruptive communication than the vocal shout. It is not that the voice was less optimal but that a cultural rule of education was operating.

A recent study on screams (Frühholz et al., 2021) has discerned six different types classified by positive or negative valence, as well as considering their immediate reaction solicitation or not (alarming and not-alarming). Each one of them has a prototypical spectrum that could be recognized both by humans as well as machines revealing that screams are more diverse than what has been previously thought. The same may be true with claps and applauses, which could be recognized between other non-vocal human sounds and even between themselves. Do they have prototypical patterns? How are claps and applauses identified in the brain?

Thus, till here, clapping seems to have five primitive common motivations over homo sapiens' history.

1. To redirect the attention of the peers toward an event or the individual himself,

2. To signal affiliation or non-menace through enthusiastic moments inviting a playful encounter between pairs,

3. Exhibition of threat in visual and auditory codes,

4. Affective message as a pseudo distance huge

5. To create collective belongingness with synchronization of behavior.

Regarding clapping as a shared cultural meaning with specific messages, its primary functions have been to communicate:

1. Approval (applause)

2. Celebrate (generally applause)

3. Show support (clap and applause)

4. Cooperate (more generally clap)

5. Intimidate (clap and applause)

Clap as a Contagious and Synchronized Act

Humans tend to synchronize themselves non-consciously in interactions at a behavioral (Ramseyer & Tschacher, 2011), and physiological level (Feldman, 2007; Konvalinka et al., 2011). Evidence suggests that interpersonal coordination in the form of mimicry or synchrony acts positively as a “social glue” (Lakin et al., 2003), signaling things such as listener involvement (Kendon, 1970) or increased rapport (Miles et al., 2009). There are multiple benefits, for instance, individuals spontaneously matching their walking speed increases the probability of them engaging in cooperation with one another (Wiltermuth & Heath, 2009), and synchronic activities increase social cohesion (Launay et al., 2016). Perhaps, the multiple synchronic activities and predisposition towards it suggest an evolutionary benefit (Mogan et al., 2017) that may extend to clapping.

Nature prompts hand-coordinated behavior like clapping since this is a phase-synchronized muscle movement pattern. Evidence shows that humans are biologically programmed to spontaneously synchronize body movements and prefer arm movement patterns in-phase coordination, while feet and legs are predisposed to anti-phase synchronization (Fitzpatrick et al., 1996). It is even surprising that humans can voluntarily coordinate their hand movement speed with other peers by just listening to how they pronounce a vocal while moving their arm rhythmically (Pouw et al., 2020).

A study by Mann et al., (2013) brings many insightful discoveries on the applause. Evidence shows that in social situations, both the onset (beginning period) and the offset (ending period) of the applause responded to a sigmoidal pattern of increase and decrease that resembles the pattern of infection and spread of diseases, supporting the idea that applause is possibly a social contagion. However, the analogy of clapping and disease transmission is not entirely equivalent since clapping increased linearly in proportion to the individuals already involved. It is argued here that it is possibly the most contagious bodily action. It is a physical reaction of mimicry that manifests in an impulsive tendency to participate in clapping with the audience members around us (Givens & White, 2021). Even if it is more conscious than yawning and under more control, it spreads faster and more widely than yawns.

According to Mann et al., (2013), both the beginning and the end of the joint action of social applause within a group seems to be subjugated to social mediation. That is, it appears that the origin and motivation of applause in groups are not due so much to the behavior of whoever is nearby or to the internal decision to continue applauding (or not). Neither is it about the type of event that triggered it, but rather it seems to depend more on the total volume provoked by the applause of others. The predominant factor is the intensity of the full sound as the triggering, diminishing, or enhancing engine of the clapping action in social contexts. Total volume affects clapping and applause so that it prolongs or stops it on its track. So, naturally, one will be under greater social 'coercion' from participating in motor synchrony of hand clapping with peers when the total volume of the sound produced is more intense.

Regarding its collective mimicry beginning, it is only necessary for one person to start clapping for this behavior to be adopted and replicated by everyone else. The fact that a single individual can spontaneously provoke a transient cooperative act between 5, 50, or 50,000 people deserve highlight as one of the few behaviors of our species that is replicated and imitated with such speed and participation. Does its power have been overlooked? Speculatively, as it is an act less representative of identity than chanting with the voice, it could increase the probability of performing it with greater anonymity and, therefore, more feasible to participate in collective social rituals than communal singing.

It should be emphasized that applauses can vary considerably in their duration without direct relation to the quality of the presentation (Mann et al., 2013). Hypothetically, the same warmth and intensity of applause can be found in an acclaimed international musical as in a school theater performance. It is necessary to recognize that common sense dictates that there will be a different predisposition to clap with different intensities and positions of the body and hands to the extent that the performance is outstanding, unique, funny, creative, and other. Nevertheless, future studies should pursue these differentiations.

In a study by Neda et al. (2000), they proposed that applause is ‘born’ spontaneously and is followed by imitation in social situations. They recorded the audience's audio during presentations in theaters and operas in Romania and Hungary, with microphones on the ceilings. They found that two stages alternate during the group applause, one of desynchronization and the other of rhythmic and synchronized applause.

Such a discovery accounts for two possible types of frequencies when clapping, differentiated by the intervals or transitions between one and the other. In one, the number of claps doubles; in the other, they decrease. One is characterized by twice the number of claps per minute being averaged compared to the different classifications. This disorganized clap is characterized by an out-of-sync period of effusive and energetic claps that double the average clap rate per minute. In opposition, the synchronized clap refers to the standard frequency of claps per minute, called rhythmic or organized claps. The speed of the organized clapping and the intervals between claps allows people to accommodate their rhythm with their peers, incrementing the synchronicity of clapping in-group members and, consequently, coordinating a rhythmic sound emitted collaboratively.

Although an increase in sound resulting from collective, coordinated individual claps is appreciated during the synchronization stage of organized claps, contrary to common sense, the intensity of the total noise decreases dramatically. What is the cause? The sound power reduces as a result of fewer clapping per minute due to the uniform of organized clapping. The explanation, in this case, seems to be that the total sound of the clapping will be louder the more the claps per minute increase, without the need for synchronization in the sound.

In summary, the observations of Néda et al. (2000) are that two types of applauses are based on frequency per minute and that the audience's applauses generally follow a relatively stable chronological scheme.

The first stage is the desynchronized ovation, which consists of "enthusiastic" applause (double frequency to the norm). As the claps per minute are abruptly or slowly decreased, it allows the sound of the applause itself to be synchronized with those of the group, which is consistent with a weakening of the total volume. After half a minute, the applause is out of sync again. They then argue that doubling the period of silence for the applause, the space of time between claps, facilitates the process of joint imitation of the action, reducing dispersion and increasing sound congruence. The behavior resembles a dynamic system because, as part of its operation, it self-regulates internally to unify the sound. It is a phenomenon of social synchrony moderated by the members who execute the action. This sequence can be repeated if, during the synchronized clapping, a group begins to perform enthusiastic claps (increase the number of claps per minute), potentially 'pulling' other members to imitate such clapping typology, which again leads to the desynchronized stage. It seems that a pendulum relationship governs social applause. Applause in theater and opera contexts - in these countries - seems to create a swing; applauses oscillate between organized and disorganized. Future studies could investigate the difference between applauses in musicals, opera, acting theater plays, classical music concerts, recitals, stand-up comedy, and other expressions of art. Even cultural differences will help researchers understand how applause is used and its variations.

Not less important is whether synchronized applause is a natural behavior or a product of culture. Future studies should unravel such a mystery.

Naturally, claps can appear with or without the presence of words or be invited or not by the speaker's word. The first researcher to investigate how a speaker can invite the audience to collaborate and participate with applauses was Atkinson (1984). Its central argument is that applause does not occur spontaneously; instead, it is caused by various behavioral and discursive aspects of the speaker working like triggers. Studies such as those by Heritage and Greatbatch (1986), Clayman (1993), and McIlvenny (1996) demonstrate the active role of the audience, and it is through non-verbal cues such as clapping and booing that they interact as a crowd with public speakers. These claps are usually elicited synchronously from the audience and are related to the speaker's words that may work as subtle or not-so-subtle nudges.

Bull and Noordhuizen (2000) explored why group applauses are synchronized. In their first study, they observed how speakers from the main British political parties during their speeches used rhetorical devices with which they indicated the appropriate moment for the public to applaud. The result was that an average of 61% of the applause converged in sync with the speaker's words. They deduced that the clap-word relationship is characterized by having a high level of agreement.

A second study (Bull & Wells, 2002) repeated the same method of scientific exploration by observing political speeches. Still, in this case, the objective was the establishment of a dual taxonomy of applause: invited and not invited. Again, the discoveries yielded substantial results. Claps being "invited" by the speaker through rhetorical elements were more likely to be synchronous between words and claps. On the other hand, the applauses that emerged "uninvited" tended almost exclusively to be a desynchronized phenomenon.

Both studies highlight that verbal language can be understood as an effective tool to encourage the production of coordinated applauses by the audience at specific moments of the speech. In addition, discursive tools, such as naming, lists of three, and constructive pairs (Atkinson, 1984), help in the joint coordination of claps.

The fact that claps, with its product, the sound (clap), is synchronized with the one from other peers, as a natural tendency (in most cultures), is not a mere coincidence but a biological tendency linked to the expression of a union. Unsystematic naturalistic observations suggest that clapping noise instinctively tends to synchronize with that of our counterparts. In studies with normal adults, the vast majority can coordinate clapping to the tempo of the music without any problem, while the difficulty is greater with jump coordination (Tranchant et al., 2016). Following Darwin, in man, the principle of imitation is a proclivity of great power (1972), which, in the case of the clap and applause, is a massive imitation by a contagion of the (usually positive) expression of individuals, similar to the pattern of spread of diseases, as was previously mentioned (Mann et al., 2013).

Nature is the cause and origin of all our behaviors as a species. Every gesture, expression, posture, or sound that humans emit from the beginning to the end of our lives is designed, influenced, limited, and acquired by our biology and also shaped by human culture and individuality. Therefore, examining signs of synchronicity within nature seems preponderant to understanding its origin in clapping and then accounting for possible ontogenetic variants.

Synchronization occurs when at least two individuals coordinate to act together. Sumpter (2010) curiously mentions that many synchronized behaviors need a leader to coordinate the action. However, the applause mimicry could emerge without a leader, although an initiator is imperative. Someone should clap first. However, in a recital, it is not the same if the person who applauds first is an unknown audience member in a 30.000 thousand crowd or the leading singer of the band over the stage. The latter is simply in a better position to start group clapping. Since collective clapping is considered a social activity, there will frequently be a hierarchy of power established in each group, at least non-consciously, within which each subject will occupy places of higher status than others. Claps and mostly applauses establish hierarchies. Generally, high-power-status individuals can initiate the spread of applause more frequently due to their ability to influence others. Future studies should consider studying and researching who the initiator is, the total sound volume between when it is initiated by a low against a high status, and its effects.

Just as humans are not the only species capable of clapping, the same happens in nature with synchrony, says Strogatz (2012), a mathematician at Cornell University, a pioneer in this field of study. He devoted much of his research to observing, detailing, and exploring the coordination of dynamic systems in chaos. He asserted that synchronized rhythmic activities could be observed in various groups of humans and animals and of different biological characteristics. An example in humans is the McClintock effect, which results from the fact that women coexisting in proximity pull the beginnings of menstrual cycles involuntarily to approximately a maximum of between one and four days apart (McClintock, 1971). The same was found with female officemates (Matteo, 1987) and mothers and daughters living together (Weller & Weller, 1993).

Why is Synchrony Important, and How Does it Work in Humans?

According to Sumpter, synchronized activities benefit species in various situations. An everyday example in cities is traffic. When using a motor vehicle, it is necessary to know how to drive and constantly circumspect the environment. In turn, drivers need to evaluate the use of physical space, intentions, and speed of other drivers, as well as to be capable of assessing in their mind the legal criteria and regulations of the law, which act as inexhaustible artificial traffic regulators (2012). The result is an uninterrupted congruent flow of pooled vehicles.

Nevertheless, some variables may interrupt or desynchronize the flow of traffic or clapping mimicry. Sometimes, due to imperfection of traffic lights, disregard of the law, or the effect of external variables. For example, as suggested by Liu (2010), in open-air concerts, the sound delay will influence the timing perception interfering with synchronization in the clapping behavior of spectators so that certain conditions can favor or discourage coordination. Laboratory evidence shows that anechoic spaces negatively affect the simultaneous coordination of the clapping sound, and reverberant conditions benefit it (Farner et al., 2009).

From an anthropological approach, clapping happens mostly in group situations, where claps can replace the word in large human gatherings, simplifying and facilitating communication. From a psychological and social conception, during group clapping, possibly a temporary state of belonging to the mass is experienced in each individual that, due to social and cultural influence, tends to replicate the behaviors and decisions of others, being this a speculative proposal. The purpose of imitation of such behavior may be, at least partially, to fit in. The explanation follows the social conformity theory (Asch, 1956).

The research of Asch consisted of a visual evaluation of a cognitive problem tested against two groups. In the first one, subjects conducted an assessment individually (control group). In the second case, the evaluation was in front of a group of participants who were several secret confederates trained to provide incorrect answers. The study's objective was to observe how often individuals can be induced to modify their decisions, even though they are correct. Surprisingly for science, participants in the alone control group had an error of 1%; in contrast, the participants in the confederate group had a dispersion error of 33%. One in three people modified their decision based on the majority's judgment. It is known today as the process of social conformity, which, as can be seen, is closely related to the process of imitation.

So, sometimes people clap because they want to send a message. At other times, people may clap not due to inner choice but rather social pressure. What is the motivation behind the clapping action when the performer has inherently no intention to do so but does it due to social pressure?

Possibly, that impulse originates from the intrinsic human need to socialize and fit in, by which subjects modify their own decisions despite the conclusions of their perceptual register or personal motivations.

To conclude this part, the coordination of clapping should be highlighted. The concordance process in clapping, organized synchrony in the sound, even between individuals with no exchange of words or visual information, is astonishingly ordered. In terms of Kricun and Stigol (2012), referring to the context of theater:

Each viewer knows when to start clapping (and in which case they should do it, and the consequences of not doing it) without having to ask others so that the phenomenon occurs with notorious synchronicity from the uniformity of hundreds of sources previously acculturated individuals on that social fact (p. 130)

It seems accurate to sustain that the situations in which people clap and applaud have been influenced throughout our development by enculturation. Both explicitly and implicitly, humans have acquired the social parameters to clap at events that have been encouraged, prohibited, and discouraged. For example, in Argentina, there is a tradition to applaud during or at the end of a grilled meal ("asado" or "barbecue"), even if the meat is raw or burned, as a token of appreciation for the chef. However, a good 'chef' knows how to recognize when that applause is due to the satisfaction of its guests rather than a token of obligated approval.

Clapping and Social Hierarchy

While clapping, there is always a sender and receiver, even if a clap is self-directed. Specifically, there is no applause of approval unless one individual elicits, one way or another, a recognition in others (including applauding yourself). In essence, clapping and applauding are primarily interpersonal behaviors.

At the moment of applauding, the behavior establishes a reciprocal interpersonal or intergroup relationship between sender and receiver. The mere presence, achievement, general conduct, or specific actions lead to a subject or several of them applauding an individual or a group. A temporal bond is created in which each member occupies a place designated by their action; applauding stipulates and imposes on another individual a place within a communication.

The relationship established usually follows the next structure. Whoever applauds decides what he wants to transmit (e.g., respect, triumph, approval) and simultaneously designates a position for himself as a sender (inferior status) and the receiver (superior status) in a vertical dimension of status. For example, it could be only momentarily that the boss applauds the employee. However, at that moment, the first focuses on the latter, indicating at least briefly an interpersonal communication proposal in which he occupies a place of lesser status. So, it is logical to interpret clapping as the establisher of asymmetric communication, in contrast to the handshake that usually works as a temporal status equalizer.

Why? From the point of view of transactional psychology, every individual who partakes in a relationship with others can position himself in one of three psychological positions concerning himself and others. That is, above, equal, or below (Berne, 1996). Humans unconsciously adopt these positions depending on personality, mood, context, the interlocutor, and other factors. For example, possibly social applause as a recognition of the achievements of others is subtly a positive social signal of submissive behavior.

Generally, whoever voluntarily executes the applause directed towards others establishes, at least at the moment or prospectively in the future, that he adopts a lower place compared to the receiver, even if it is only during the period that the applause is prolonged. For example, everyone once applauded the happy birthday to a friend, family member, or acquaintance. The only person who should not be clapping during that given moment is the birthday person! It is a recognition that he has achieved one more year of life, which is the event that several cultures reward. The person who has earned the privilege of not applauding is the one who is placed by the audience temporarily in a position of higher social status.

Sometimes even the most dominant member of the group is the one who has the prerogative to applaud. They will decide if the receiver deserves the applause, and if so, it will be the initiator of the applause. The other members could follow and replicate the volume and enthusiasm produced by the first.

There are many people with introverted, neurotic, or submissive traits who, out of humility or shyness, applaud when they should not, like when being chanted their birthday. Could this be a way of mitigating the established asymmetric relationship? What are the personality traits related to major proclivity into spontaneously beginning to clap or disposition of being infected by clapping influence? Here it is argued that the propensity to clap and its intensity may reveal the proclivity to prosociality and giving compliments to other people. More research is needed.

Whenever an individual gives applause directed at another, it usually sends a message translatable to words like "I applaud you because you gave me or did something," "because you deserve it," or "because culture tells me that it is time to reward you based on your behavior." The dominant premise in this interaction is the approval-gratification sequence. This communication equation consists of the following: Individual A acts. Individual B applauds (approves); consequently, Individual A feels joy, pride (gratification), or a positive inner state. It is the most straightforward explanation of the behavior of applause as a positive reinforcer, but, as it is evident, clap functions are more complex and intricate than just "approval."

It should be added that claps do not always establish unequal communication between interlocutors; instead, they sometimes work, creating reciprocal equality between sender and receiver. Such exceptions to the rule are at the foundations of nonverbal communication and should always be in the mind of researchers while studying particular behaviors.

The idea that applauses may result in reciprocity or reciprocal relationships is based on an ethological perspective. The action of applauding visually exhibits emptiness in the hands. Also, it reveals that hands have no weapons and, by extension, visually and audibly, no objects are at their disposal to hit or throw. Both arms are busy in a ritualized and predictable action that sustains a constant rhythm, unable to carry out a powerful attack. At primitive times, this could be an effective calming signal of "no threat" to whoever is the recipient of the behavior, complementing the mentioned non-menacing message. A verbal message of "I am not going to attack you" may be conveyed, quite different from the "visual display of menace" of clapping. Clapping, unlike a dance, is a discreet, rhythmic, and predictable action; therefore, it may reduce the uncertainty of the senders' intention.

Overall, the decoding of the applause is usually that of a signal of subordination ("you are more important than me" or "deserve my recognition") or reciprocity ("we are at the same level"). Nevertheless, exceptions are always the rule, such as clapping and applauding with a threatening face and a hostile bodily attitude, which would immediately modify the intentionality of the message.

Synchrony Unity and Equality

Another essential emerging principle of social clapping appears here. Clapping within a group necessarily implies a momentary feeling of unity. In that particular period, a symmetrical link is established, even if the message is approval, to create musical percussion or dance with the pairs being friends, teammates, or an audience of unknowns. Verbally it says, "I agree with them, and they agree with me." Nobody is below and above; they are all equal—democratic consensus.

Interestingly, greetings (welcome, farewell, and celebration) are one of the brief instances during which status differences are temporarily suspended, resulting in temporary equality (Morris, 1977). Could it be that clapping works in s similar fashion? Could it be one of those behaviors that unite individuals and crowds, expressing collective agreement? Clapping in a group could increase the perception of belonging and unity.

Could the moments of synchrony fulfill a central function for societies, and it is none other than suspending social differences resulting from hierarchies in abeyance? For example, everyone occupies the same position and degree of importance during toasting, except the one who proposes it or receives the praise. Other similar social situations are the moments of prayer, singing the hymn, and a minute of silence, all situations of collective nonverbal collaboration. Could applause be a more important factor of social unity than currently given?

The fact is that executing claps collectively inevitably positions people in a role of at least parity in transactional theory. However, if claps are directed toward another person or group, they may place the performer in a position of inferiority (lower status). Being the receiver of claps and applauses usually temporarily enhances the social position above others. Instead, participating in group claps makes clappers part of it, temporally at the same level.

Hence, as a hypothesis, since applauding others is a behavior corresponding to compliance, subordination, or congratulation, it is probable that those who have dominant and arrogant personality traits will be less likely to imitate it and even less likely that the expression spontaneously emanates when others are worthy of such approval.

Is it possible that the variations in susceptibility to engage in it or the acoustic or morphology of the clap give clues about the personality? It may be so, but still, there is no research on that to this date.

The Role of Culture in Applause and Claps

The cultural factors establish the norms that regulate the socially accepted triggers and timing of clapping and applauding. It is the culture rules that, in a certain way, generate an implicit and explicit schedule about the most appropriate time to clap, to whom, when, and how. The explanation consists of what Ekman and Friesen (1969) coined as "display rules." Parents, important figures throughout childhood and adolescence, teachers, society, and media, both verbally and implicitly, shape how and when individuals should display, perceive and interpret (decoding rules; Buck, 1984) their own and strangers’ emotions. Culturized individuals have been instructed on what situations, emotions, and intensity they should react to particular perceptions of stimuli and events. This refers mainly to emotional norms, which are a particular way of limiting people's actions within the culture to which they belong. It is not the same reaction of an Argentine or a German when they perceive that a passerby has dropped a piece of paper on the public street. The enculturation process of culture members is different, as well as the proclivity to feel and express certain emotions; therefore, the same stimulus gives rise to different responses. Each culture has its own cultural rules (coding/display and decoding/interpreting).

Thus, evidence suggests that each culture holds parameters on when, how, and with what intensity and to whom it is acceptable to clap and applaud, whether at public or social events. The individual decision to applaud or not to applaud may seem at least an evaluation based on the person's idiosyncrasy. However, the manifestation is also linked inevitably to the internalized norms of the culture.

As Ray Birdwhistell (1970) explained, communication theory consists of a dual interaction (at least) in which A does not communicate with B, nor does B communicate with A, but A and B are in communication. During communication, the members can intervene and even regulate the interaction flow by employing a smile, a shout, a phrase, a look, a gesture, among many possibilities, or a clap. In addition, during the communication process, the participating individuals can act as regulators, as communicational "referees." An example is when the public speaker points his palm towards the public during a political speech as a sign of "stop" because he solicits silence and wants to say a few words.

People can elicit the claps and applauses, intensify, de-intensify, prolong, shorten, or stop it altogether with verbal and nonverbal cues directed to audiences. It logically follows the concept that whoever occupies the place with the highest status is the orchestrator, who has the best chance of coordinating claps and applauses or receiving them. For example, during social interactions, from the hierarchical perspective of transactional analysis by Eric Berne (1996), it is the most dominant person who frequently - voluntarily and involuntarily - regulates the use of time (Burgoon & Dunbar, 2006).

The subjective experience of receiving applauses

Once again, it seems necessary to emphasize that claps directed towards other individuals as a social behavior have the purpose of showing predominantly signs of approval, meaning claps use as applauses, equivalent to "I applaud you because you deserve it," "I applaud you in gratitude" or "your actions or words deserve recognition." It is a non-verbal reward.

When words are unsuitable (when being an audience member at a 1000-person conference) or are inadequate to express a message (e.g., in the dark), clapping is used as a substitute vehicle for communication. The truth is that, as with emotions, applauses vary in their positive intentionality. It ranges in a continuum from mild approval to a standing ovation. It could also be argued that there is not just one but multiple graded scales of possible messages on different dimensions like respect, enthusiasm, likability, and more being communicated through applauses. A multi-dimensional messages spectrum of applauses could be studied in the future.

On the part of those who have obtained as a product of their actions, achievements, or reputation, applauses of their peers will indeed have experienced satisfaction and enjoyment. Since the applause seem to submit the person to a moment of well-being (in most cases), it is likely that ontogenetically, humans have reiterated behaviors that spurred the applause of others towards them. Perhaps a portion of adulthood behaviors results from receiving the non-verbal approval of applause by the closest influential figures over childhood. For instance, after completing a task, the child who received a series of applause may try to replicate that behavior in the future to revive the positive reinforcement. It is a response to the law of effect. Depending on the level of positivity experienced after the performance of the action, the organism tends to repeat or not the action. An 18th-century English writer, Samuel Johnson (1798), wisely wrote, "The applause of a single human being has great consequences in the life of a person."

Having proposed its possible primitive and ontogenetical origins, some functions, synchrony, and the relationship established between sender and receiver, among other elements of value, it seems appropriate to now move to the subjective experience while receiving applauses.

Claps and applauses could potentially trigger a series of physiological modifications in the receiver, which has not been studied yet. Studies do not seem to have given a reasonable level of importance to information that appears endogenous about clapping. What will happen if the investigation is focused on the internal sensations of the receiving subject at the moment of the applause?

Ten professional musical comedy actors were briefly informally interviewed9. They answered a short, four-question questionnaire verbally. It was expected that workers in the field of art and acting would have a certain level of self-perception of internal processes in the face of habitual stimuli in their daily life, such as applause, retribution, or gratitude that the public offer them after each presentation.

In contrast to expectations, it was curious to observe how much cognitive reflection a simple question demanded of them: "What do you feel when they applaud you?" Perplexity and imbalance articulate the most repeated nonverbal reaction by several respondents. More than half resorted to taking several seconds, reflecting, and only then, making their feelings explicit. The results were overwhelming. Undoubtedly and consistently, all but one associated receiving applause with provoking positive and pleasant feelings and emotions, such as gratification, validation, approval, pleasure, fulfillment, joy, and increased self-esteem. Yet, with a strange sense of discomfort, only one of them commented.

The most surprising finding, contrary to what can be expected in terms of subjective experience and bodily sensations, is that every one of them converged on the answer to the following question: "In which part of the body do you experience the sensations caused by the applauses?". Their response always indicated that the experience was at the upper portion of the trunk, chest, or specifically at the solar plexus—one hundred percent agreement.

These results align with the study by Nummenmaa et al., (2014), who surveyed 701 participants to map the body's somatosensory and physiological sensations of emotions. They accumulated a pan-cultural emotional atlas. When relating the previous results with the responses of the ten actors, emotions and feelings that present intense sensations in the part of the chest are: Joy, pride, love, anger, and anxiety. The first three coincide with the words used by the ten actors to describe the emotional and bodily experience of receiving applause as well as the subjective bodily experience. Future studies should address this correlation. Also, neuroscience research could explore brain activity while receiving applauses.

Conclusion

Clapping and applause are two different behaviors. The first is a nonverbal phonokinesic manner that mechanically produces an acoustic sound after bursting a bubble of air between both palms of the hands. Different from clapping, applauses are claps that convey a meaning of approval, most usually used in a rhythmic, repetitive sequence.

This may be the first literature review on the complex polysemic and multipurpose behavior of clapping, and even it tried to bring several interdisciplinary lenses to study the same behavior, many historical and current aspects of how it functions, its variations, frequency, and so many more aspects still are yet to understand.

In the following essay, a series of typologies of clapping will be suggested. It is possible to classify it by function, by a single or consecutive clap, as a subset of several categories of audible body movements, based on the number of people clapping being an isolated group or by a vast proportion of the audience, based on the resulting experience of the receiver and last but not least, based on if the claps are self or other-directed. There is one more possibility that requires dense description, classifying clapping based on the morphology of the action, from the fingers, hands, arms, and face.

Alan Crawley

has a degree in psychology and is dedicated to studying Nonverbal Communication (NVC). At the moment researcher at Universidad del Salvador (USAL) since 2020 and an upcoming Ph.D. student at the University of California, Santa Barbara (UCSB) in September of 2023. He has contributed as coauthor of chapters in two edited scholarly books on Nonverbal communication published in 2022 and one upcoming in 2024. He is frequently invited as a lecturer for national and international universities for face-to-face and online classes on NVC.

Author Contributions

I am the only author

Declarations

Competing Interests

The authors have no competing interests to declare that are relevant to the content of this article.