Raskin (1985) develops a theory, the Semantic-Script Theory of Humor, (SSTH), a theory of humour competence whose intended coverage is primarily short verbal jokes.

The main theoretical innovation one finds in (Raskin 1985) is an attempt to explicate textual incongruity formally:7

Scripts were introduced by Schank & Abelson (1977) and can be explicated in various ways (Raskin 2017); the same applies to opposite. We will make a proposal of our own as regards incongruity, one that refines (2). The theoretical apparatus for explicating jokes in subsequent theories such as the General Theory of Verbal Humor (Attardo & Raskin 1991; 2017) is significantly more complex.8 However, (2) remains a key notion. This approach ties incongruity to the general theory of scripts, viewed as embedded in ontology construction (Raskin 2017); this might have seemed idiosyncratic when it appeared in the 1980s, but currently is closely related to frames (Fillmore 1985; Löbner 2015) and to semantics as ontology construction (cf. situation semantics (Barwise & Perry 1983; Ginzburg 2011)).

Nonetheless, work on humour theory exemplified by SSTH and the GTVH has different aims from ours: our aim is to explicate the possibilities of laughter occurrence in conversation, in particular the relation between laughter events and laughables, the triggers or objects of laughter (more on which see sections 2.2 and 3.). In contrast, the avowed quarry of humour theorists is characterizing humour competence. (3) taken from the corpus collected for (Priego-Valverde et al. 2018) exemplifies how laughter can emerge without the laughable per se having any incongruous aspect. In this case the laughable is the utterance “this morning’s semantics class”, which is an answer to the question “What would you like to speak about?”. Nothing in this question/answer sequence is incongruous relative to any script or other related notion encoding domain knowledge; the laughter arises from some implicit shared knowledge about the denoted event. Minimally, this means that a theory of laughter needs to involve contextual resolution of implicit aspects of laughables.910

However, a more significant point, exemplified copiously below, is that much laughter in conversation is not related to jokes or witticisms; indeed, various corpus studies reveal a high percentage of speaker laughter which lacks the surprise element key to jokes (Provine & Yong 1991; Vettin & Todt 2004).

Gail Jefferson initiated work within Conversation Analysis on laughter (e.g., (Jefferson et al. 1977; Jefferson 1979)). A crucial assumption that Jefferson makes is to treat laughter as a possible response in the range of responses an utterance generates. This is an assumption we adopt in the sequel. Specifically, Jefferson takes a strategic view of laughter, viewing it as a social activity that a speaker can invite others to join in, one which occurs frequently with material which has no humorous aspect as such. This is exemplified here by (4a). These are instances of antiphonal laughter, “responsive laughter” whereby the responder shares the initial laugher’s assessment of the situation. Jefferson also points out cases such as (4b), where laughter is not responded to with laughter, though the responder addresses the direct issue raised.

Capturing these contrasting options is clearly a requirement for any theory of laughter in conversation, as is the need for distinguishing laughter potential in 2-person and multi-party conversation, in light of observations by Glenn (2003). Another notion arising from (Glenn 2003) is the notion of laughable: laughter marks its referent as laughable and potentially funny. This is a key starting point for any semantic theory of laughter. Work in CA has documented the use of laughter in a variety of non-humorous settings: medical (Haakana 1999) (where doctors often avoid responding to a patient’s laughter with laughter), job interview situations (Glenn 2013) (see example (20a) below), political interviews (Romaniuk 2013), where politicians use laughter to deflect questions, exemplified here in (5), which is further discussed in section 4.

Conversation Analysis work on laughter has, as we have seen, led to many important insights. As Glenn & Holt (2013) explain CA associates laughables as “referents” for laughter but, as with CA work in other domains,11 explicitly assumes no semantics beyond this (repeated from footnote 2): “… Although laughter lacks semantic or linguistic content, variations in its production contribute to its communicative value.” (Glenn & Holt 2013: 6); indeed in their survey, Glenn and Holt point out how CA work recognizes a variety of effects laughter can produce, while offering a careful description of these uses and the positions in which they occur:

But in the absence of anything more than a “referential semantics” in terms of laughables these remain an essentially arbitrary list of effects. Moreover, since CA avoids any explicit means of representing emotion, in saying that laughter can serve as a stance marker, it has no way to distinguish laughter in such cases from verbal post-completion stance markers such as yea and mmh; (see concrete discussion of such cases in section 3.6 below.). Nor can one capture the non-translatability of laughter potential (see below section 4.3.3).

The view of laughter we develop assumes that laughter is ambiguous and in many cases has propositional content that arises from an eventive source. Starting with the last point, we wish to emphasize a certain similarity in behaviour with eventive anaphors, here exemplified by demonstrative NPs. Both can take as antecedents exophoric antecedents (see (7)), the event described by the preceding utterance (see (8)), an event occuring utterance medially—e.g., a sub-utterance or co–speech gesture (see (9)), and, finally, an event described cumulatively (Asher 1993) (see (10)):

Each of the events predicated about in (7)–(10) are what we refer to subsequently as the laughable, a notion introduced in a related if not identical sense in the CA literature (see section 2). This laughable l, we suggest, is a constituent of laughter content, which informally can be either (11a) or (11b). We leave both incongruity and pleasure unexplicated for now until sections 4 (for incongruity) and 5 (for pleasantness).12

Indeed already the data (7)–(10) provides us with the means to distinguish laughter from unintentional bodily sound productions like sneezing and hiccuping. With respect to e.g., (7)–(8), if C enters and sees B laughing, she could pose the question in (12a). B’s response indicates that the laughter is directed at certain events she has perceived (visually, aurally, or via touch, as with tickling) with her laughter being used to express her view that this is, say, incongruous or pleasant—the difference here is immaterial; this contrasts clearly with (12b,c), where the trigger is bodily:13

One could be tempted also to say that there is a contrast in (12) in that sneezing and hiccuping are involuntary. However, while some cases of external–event–directed laughter seem to be as voluntary (say in the sense of “consciously planned signals”) as verbal speech, and while in some neuroscience studies of laughter under experimental conditions in a laboratory, a distinction has been drawn between genuine, “involuntary” and fake, “planned” laughter (Wild et al. 2003; McGettigan et al. 2013), this is far harder to assess for laughter in spontaneous conversation (Wierzbicka 2000; Gervais & Wilson 2005).

Nonetheless, while this dimension is significant pragmatically, we do not take it to be qualitatively more significant than it is for verbal utterances. Indeed one can find similar, “involuntary” occurrences with the latter, in other words verbal utterances that take place without the speaker’s (full) “conscious control”—apologies, as in (13a), exclamations (13b), or “errors” such as making an utterance in the “wrong” language (13c):

At the same time, the two main imports communicated by laughter—however packaged—incongruity and pleasure are both susceptible to occur “spontaneously” and “reflectively”. Thus, when someone laughs at a joke, an instance of an incongruity, we are likely to consider whether the laugh is “genuine/spontaneous” or “fake/forced”. A child laughing wildly while playing with a toy is an example that would obviously be viewed as spontaneous pleasure, as would a mutually flirtatious couple (Fuchs & Rathcke 2018), though in the latter case the issue of “genuine/spontaneous” or “fake/voluntary” is certainly one that can arise.

Given that interlocutors are aware of the possibility that laughter can be “spontaneous” or not, this is an important pragmatic issue that potentially arises in any context when non-spontaneity is associated with lack of sincerity.14 This, then, actually ties laughter (and smiling, frowning, crying etc) to verbally expressed speech acts, for which an analogous sincerity issue arises frequently, as much emphasized by Austin (1962); Searle (1969).

With some initial notion of what laughter content consists of, we now turn to data illustrating further motivation to posit such content, its interaction with verbal content, and the ambiguity of laughter.

One additional piece of evidence for the claim that laughter has propositional content is that it can be used as a stand-alone utterance whose content incorporates content from the immediate context and such that changes in the linguistic context lead to different contents for a laugh: it can convey—we will suggest in section 4 via pragmatic inference— a negative response to a polar question, as in (14a)15 or disbelief in the previously uttered assertion, as in (14b), based on an advertisement from the Paris metro, the biblical (14c), and (14d); (14e,f), taken from newspaper reports on parliamentary debates, offer essentially such a paraphrase verbatim:

As expected from a signal bearing propositional content, laughter can have a force that may be disputed in conversation, as illustrated in (15):16 in (15a) the audience laughter indicates that they view the speaker’s claim as non-serious; the lecturer’s retort disputes this reaction (though in a somewhat double–edged way, transferring the belief in the claim he appeared to be making to General MacArthur); in (15b) Unknown disputes Danny’s laugh and the funniness it putatively ascribes to someone being tied to a railway track:17

Just as with other meaning–bearing linguistic elements, varying the placement of laughter can vary the content—this applies to other non–verbal social signals such as smiles, sighs, eyebrow raising, sniffles (see (Krahmer et al. 2002) for eyebrow raising and focus.). Here we point to the effect achievable by low arousal laughter within an utterance. This enables such laughter to serve as a scare-quoting device (Predelli 2003): in (16a(i)) the term long term friend is presented as a euphemism, whereas in (16a(ii)) it is the term friend which is at issue; (16b) exemplifies an analogous effect where in (i) the issue is what is to be pressed, whereas in (ii) it is what entity the red object is; similar remarks apply to (16c), which involves a sigh rather than a laugh:18

At least some of the implicatures that have been the focus of much work in pragmatics since (Grice 1989) and whose origin (grammar or intentional reasoning) is currently a source of much debate (e.g., (Chierchia 2006; Geurts & van Tiel 2013)) can be triggered as a result of laughter and smiling. In (17a) a quantity implicature arises by exploiting a ⟨laughter, smile⟩ scale,19 whereas in (17b) a relevance implicature arises, presumably on the basis that a laugh in such a context—unless it is seen to be a nervous laugh—expresses pleasure at the news communicated by A, which is inappropriate:

As we saw when discussing scare quotation, laughter can be used to mark irony—to indicate that an utterance is meant to deviate from its literal meaning. By the same token, irony can affect laughter, smiling, or crying: in all cases, there is a composition of a basic meaning of the non-verbal signal with a meaning roughly paraphrasable as ‘I don’t really mean this’. Mouthing “ha ha” as a reaction to a joke or humourously intended comment conveys that the speaker does not actually find the joke funny or the comment humourous, as in (18a,b); similar comments mutatis mutandis apply to smiling, crying and sighing, as in (18c,d,e):

The data we have seen hitherto all involve laughter that communicates an essentially “disruptive” or “negative” force—used to communicate irony, scare quotation, question unworthiness etc. We will unify these within one meaning incongruity laughter. However, not all laughter has such a force. There is a significant class of “positive”, affiliative, empathetic laughters, which we will unify as pleasant (a notion we introduced earlier and is explicated in detail in section 5.). In his novel The Book of Laughter and Forgetting Kundera (1996) explicitly suggests the existence of two forces laughter can have, which correspond quite closely with the opposition we propose to make here.20

(19) exemplifies such an empathetic laughter, where there is no incongruity to associate with the laughable, the pleasing prospect of Fred’s holiday:

(20) seems to function as an acknowledgement; the laugh is a more effective means than a simple, verbal acknowledgement; a verbal acknowledgement (e.g., Right or Yeah) would involve explicitly agreeing with a compliment and could be perceived as arrogant; Empathetic or affiliative laughter conveys pleasure of sharing the situation with the speaker and, only indirectly (by a mechanism elucidated in section 5) acts as agreement:21

Laughter can occur simultaneously with speech, both in cases of speech laughter, where a speaker speaks and laughs simultaneously (Kohler 2008), and where one interlocutor is speaking and the other is laughing. Is this an aspect that distinguishes speech from laughter?22 A detailed answer would need to consider and compare in a detailed way overlapping in speech and laughter, which we cannot do here. Nonetheless, at least qualitatively, one can offer a negative answer in that verbal acknowledgements/back channels, akin to but distinct in effect to empathetic laughs, can certainly occur simultaneously with speech by another interlocutor, particularly during a long turn by the latter (e.g., where the latter is a lecturer responding to questions in an academic setting.). This applies equally to other proposition–denoting gestures such as (negation–conveying) head shaking (Kendon 2002) and head nodding (Wagner et al. 2014), as well as their non-sentential analogues yes and no.

We propose to view laughables as Austinian propositions, comprising the laughable event and its description, a record type. (33) offers some examples: in (33a) the laughable is simply a perceived event of a man slipping over a banana peel; in (33b) the laughable is the utterance by A ‘Bill is absurd’, whereas in (33c) the laughable is the utterance “friend”:26

Like Raskin we think that incongruity needs to be explicated in terms of a clash. For Raskin the clash is between two objects (scripts) at the level of types. However, given that incongruity in conversation must apply to laughables (real world events), we refine slightly a proposal by (Ginzburg et al. 2015) to yield a view of incongruity as a clash between (an enthymeme triggered by) the laughable and a topos that represents ‘congruity’, i.e., the much more probable course of action.27 That is, the laughable l satisfies the domain type of an enthymeme, but there is a clash between the range of this enthymeme and that of a topos which would license an enthymeme more expected in the circumstances. In (34), p is a proposition comprised of l, the laughable event, and L a type that classifies l, E is the triggered enthymeme, and τ is the clashing topos—E’s domain is a subtype of τ, but its range (L₁) is incompatible with τ’s range:

We exemplify this definition with several distinct types of effects we have seen before:

We can now offer a lexical entry for a laugh that expresses incongruity.3435 This lexical entry indicates about the signal whose phonological type is lphontype, on which more shortly, that given a context which supplies a laughable p and topos τ, the laugh has as content the proposition that p is incongruous relative to τ. Moreover, the laughable is incongruous to a contextually given degree δ, constrained by a relation whose other argument is the arousal encoded in the laughter’s phonetics.

FIX FIX FIX!

A number of key aspects remain underspecified in this entry for reasons we explain now:

We will explicate pleasure in laughter by attempting to incorporate a cognitive theory of emotion into our dialogue theory. There are a variety of theories of emotion. Although important early work on facial gestures came from researchers espousing theories postulating a small number of basic emotions see e.g., (Ekman et al. 1987), there has been little evidence to support the existence of physiological characteristics that instances of a single emotion share but that other emotions do not (Scherer & Ellgring 2007; Barrett 2017). A variety of approaches have emerged that avoid such an assumption. We mention here two influential approaches, emotion constructivism and approaches based on appraisal; both provide useful means for classifying laughables, smileables, sighables etc and the emotional episodes they give rise to.42 Emotion constructivism e.g., (Russell 2003; Barrett 2017) views emotional episodes as arising from a categorisation process of the triggering event in terms of previous event “exemplars” on the basis of a resemblance in terms of certain dimensions. In the account of Russell (2003) these include core affect (a two dimensional matrix of (un)pleasantness and arousal), affective quality, and the object causally involved in the event. Appraisal approaches also view emotional episodes in terms of appraising events in relation to concerns. An initial automatic appraisal takes place that does not require conscious processing. This is followed by a secondary appraisal that often includes conscious reflection and that can lead to new intentions. As an example of such an approach consider the Component Process Model (CPM) of appraisal developed by Klaus Scherer (see e.g., (Scherer 2009)). On this view, appraisal of an event and its consequences can be structured on the basis of a number of criteria or stimulus evaluation checks, each of which has certain physiological correlates:43

The computational framework EMA (EMotion and Adaptation) (Gratch & Marsella 2004; Marsella et al. 2010; Traum et al. 2008) implements a view of appraisal quite close to that of the Component Process Model. There are some significant differences, nonetheless. Thus, EMA does not subscribe to the assumption that the stimulus evaluation checks are strictly ordered, and we follow EMA in this respect. EMA treats appraisal as a set of feature detectors that map features of the agent’s current view of the agent-environment relationship into appraisal variables.

In order to integrate emotion–related information into the Dialogue Gameboard, we posit an additional field we will dub Mood. Mood represents the publicly accessible emotional aspect of an agent that arises by publicly visible/audible actions (such as non-verbal social signals). This can but need not diverge from the private emotional state—as with insincere illocutionary acts, one manifestation of a “fake” laugh/smile is a laugh/smile that does not reflect genuine pleasure;45 it can also involve the lack of a genuine belief that the laughable is incongruous.

We view Mood as a complex entity built from categorisation dimensions/appraisal values. More specifically, we assume that it is a weighted sum of these values.46 We treat each appraisal as being a record of the type Appraisal, given in (50). We posit this type to be, following Russell (2003), the Component Process Model and EMA, a record type with three fields pleasant, responsible, power, each field corresponding to a Russellian dimension or an answer to a stimulus evaluation check. We restrict attention here to these dimensions, which seem needed for the purposes of this paper. Pleasantness is specified via a scalar predicate Pleasant which can be positively valenced (value tracked by the label pve) or negatively valenced (value tracked by the label nve) or both (when both pve and nve have non-zero values.); the latter case corresponds to the case of mixed emotions (Minsky 2007), which in practice are relatively common (Oatley & Duncan 1994). Specifically for our current interest, this can be exemplified on the one hand by the case of a joke told in a funeral and, conversely, by the case of a sigh occurring when one is generally in a rather elated mood. Power is specified in terms of a scalar predicate Powerful whose lower bound (zero) arises when the agent perceives total lack of control vis à vis the appraised event.

As mentioned above, this leads to the postulation of a modified type for the dialogue gameboard, with a field for Mood:

We do not offer here a general theory of how emotion categorisations/appraisals arise47—we will restrict attention below to the effect laughter and other social signals can have on the parameters of appraisal. Nonetheless, we make a number of assumptions concerning how Mood gets updated and introduce one abbreviation for two recurring operations. We assume that the most recent value of numerical components of Mood should be given a stronger weight than its current value, which itself represents some combination of the earlier ones. Therefore we postulate a weighting between the contribution of the new appraisal and the current value of a field of Mood. If this field also has a non-zero negative value, the weighting will attenuate it, otherwise it will have no effect.

Thus, an update rule that increments the positive pleasantness recorded in Mood to an extent given by the weight ɛ is given in (52a), whereas the converse operation of incrementing the negative pleasantness is given in (52b). We exemplify the application of positive pleasantness update for δ = 12, ɛ = .25 in (52c):

We will assume for simplicity that the weighting ɛ has a fixed value for any given agent and will not—as we formally should—specify it each time as a parameter of an agent’s private cognitive state.

We can now formulate a lexical entry for pleasantness laughter, as in (53a): the content we posit is that the laughable is pleasant for the speaker to a contextually given degree δ. The effect of such laughter on the speaker is captured in terms of an update rule that increments the (positive) pleasantness recorded in Mood to an extent given by the weight ɛ, as described earlier. Note that this conversational rule is what we dubbed above participant sensitive: it can apply only to someone laughing; this ensures that in order to boost one’s Mood.pleasantness (which represents one’s public emotional state) one is actually required to laugh (or engage in other action, as we will see below.).484950

From pleasantness, we can derive three functions of laughter: affiliation, empathetic acknowledgement, and (with additional assumptions) superiority. We take these in turn.

What of the pleasantness that occurs with much incongruous laughter? This can be captured by a simple refinement of (53)—adding as a disjunct that the trigger for the Mood update can also be an incongruity content, as in (42). This means that incongruous laughter will communicate (i) that the laughable p_lis incongruous relative to some topos τ and (ii) that the speaker is (momentarily) pleased.

This seems sufficient for cases like irony signalling (35) and scare quoting (39). In other cases, however, arguably the pleasure is actually incorporated in the incongruity. Thus, (54b) which denies the pleasure but not the incongruity seems a more natural reaction than (54c), which denies the latter:

One way of capturing this additional inference is by positing a topos that finding an entity incongruous involves that fact itself being pleasant:

The smile is characterized by the upward turn of the corners of the lips, which is produced by the contraction of the zygomaticus major muscle (Ekman et al. 1987). Ever since Darwin, the relationship between laughter and smiling has been a key question. Darwin’s view was, essentially, that smiling is a low arousal version of laughter.51 One consideration in favour of this is the scalar relationship between laughter and smiling discussed earlier—when a laugh is expected, production of a smile implicates that laughter cannot be provided because the stimulus is insufficiently funny/pleasant. More generally, there is a large though not complete overlap in the effects that laughter and smiling can bring about: in addition to pleasant incongruity, these include affiliation and the expression of superiority or dominance over one’s interlocutor (Niedenthal et al. 2010)—this latter can be viewed a “low arousal” version of the effect of mockery discussed above for laughter.

As with laughter, a definitive taxonomy of uses is still a matter of controversy. An extreme case is Ekman (2009), who identifies 18 types of smiles and suggests that there might be as many as 50 in all. A more minimalist view is that of Niedenthal et al. (2010), who suggest that many smiles are simply readouts of positive internal states such as happiness; this holds also for the “play-face” in primates, such as chimpanzees (for the latter, see discussion in section 7.) Such a meaning for a smile is analogous to our pleasantness meaning for laughter. However, Niedenthal et al. (2010) distinguish this from two other types—affiliative and dominance smiles. As we pointed out above for laughter, affiliation and mockery can actually be deduced from pleasantness uses. This does not rule out positing these as basic meanings for smiles, but leaves open the possibility that these, like many other effects of smiling noted inter alia by Ekman, are actually pragmatic inferences.

These and the corresponding scalar implicatures could be captured by positing lexical entries for smiles that correspond to the ones we have posited for laughter; given our formulation, the pleasantness update rule will apply without further stipulation. There are two clear differences, however, signalled in (56) in bold. The first concerns form, which needs to be specified in terms of various parameters pertaining to facial shape/activity (the Zygomaticus major and orbicularus orbi muscles); as with laughter we abstract away from this using the label smileshape; the second difference concerns arousal—the range of arousal needs to be bounded so as to, roughly, be less than the arousal achieved by high arousal laughter; in other words, we assume that smiling is restricted to low and medium arousal.

Sighs—breaths with a volume at least twice as large as the mean volume during a surrounding representative time interval (Vlemincx et al. 2017)— are ambiguous signals in conversation. They can be produced for purely physiological reasons to allow the respiratory system to return to a homeostatic state with respect to blood gas levels, but they can also be produced with communicative intent.

Teigen (2008) suggests that the prototypical sigh conveys discrepancy (something is wrong) accompanied by acceptance (there is nothing to be done). Such a meaning is straightforward to describe in the current set up, as we will see shortly. However, the most extensive corpus study of sighs we are aware of, the study by (Cash & Ginzburg 2019) of more than 100 sighs in the BNC, points to an additional class of sighs, positively valenced sighs, that are much more frequent than commonly believed. In the data of (Cash & Ginzburg 2019) they occur 46% of the time, and moreover seem to be partly correlated with whether the sigh is same/cross-turn with respect to the sighable: 29% of sighs in answers are positive, contrasting with 58% in queries. Sighs are typically low arousal (as noted also by Teigen and Vlemincx et al)—only 11% of the sample of (Cash & Ginzburg 2019) are high arousal. However, of the high arousal sighs a very large proportion—82%—are positively valenced.

A first approximation this suggests is to distinguish non–high arousal sighs from high arousal ones, associating the former with negative pleasantness and a sense of powerlessness, the latter with positive pleasantness and possibly relief. Respective lexical entries are (57a,c), whereas (57b) is an update rule associated with (57a), incrementing the negative pleasantness and setting the power arousal level to zero. The force of a positive sigh (57c) is postulated to be simply Pleasant, which makes it trigger the same update rule as for smiling and laughter, namely (57b).

By comparison with other non-verbal signals mentioned here, eye rolling has not been much studied and we are not aware of a major corpus study, though see (Goodwin & Alim 2010) for some discussion.

We mention here three attested examples:

This suggest the following basic description: the eye roller views the eye-rollable as ridiculous; this effects a decrease in the eye roller’s mood for which some person or organization R is responsible. Here the notion of ridiculous is akin to, but distinct from incongruity, and thereby relative to a topos. Hence the following lexical entry:

Wierzbicka (2000) attempts to find a general meaning for drawing one’s eyebrows together and plumps for an earlier intuition of Scherer (1992), who speaks of the perception of some type of discrepancy between one’s needs or goals and one’s actual circumstances. Wierzbicka tries to explicate this as I want to do something, but I know I’m not doing it now. Kaukomaa et al. (2014) suggest with respect to turn–opening frowns that they are related to the emergence of a problem, relate to negative assessment and lack of affiliation across participants. The constructed example (60a) indicates the possibility of a frown as part of clarification interaction, whereas (60b) exemplifies a frown in self-repair:

We refine these proposals by viewing discrepancy and problem emergence as involving the frownable giving rise to a question, which can indeed be explicitly posed, as in (60); this is associated with a Mood update in which power is non-zero and pleasantness is decreased.

In this paper we have refuted a view that has dominated research on formal grammar since the influential typology of Trager (1961) that views laughter as paralinguistic, hence lacking meaning akin to what words and phrases possess and not contributing to the compositional construction of meaning. We have shown that, in fact, laughter has propositional content: we show that it involves reference to external real world events, quite analogously to event anaphors and in contradistinction to bodily signals like sneezing and hiccuping, a view that can be traced back to Plessner (1970). We suggest that laughter has stand alone meanings and that it participates in semantic and pragmatic processes like repair, implicature, and irony.

We have shown how to develop a formal semantic and pragmatic account of laughter embedded in a general theory of conversational interaction. This novel view of laughter enables us to capture in a unified and rigorous manner previous insights concerning laughter, including those from Conversation Analysis and those emanating from linguists working on humour. From CA, in particular Gail Jefferson, we take the assumption that laughter can be and often is an intentionally produced signal included in the range of responses an utterance generates.

Echoing a parable of Milan Kundera’s, our account, couched within the framework KoS, posits two distinct meanings for laughter, one based on incongruity exhibited by the laughable, the other based on pleasure the laughable causes to the laugher. Building on Raskin’s work in humour theory, we explicate incongruity as a notion that relates a contextually salient entity l with a defeasible rule (a topos) in case there exists a contextually salient characterization of l that is incompatible with τ. With this view of incongruity, which is closely related to the TTR notion of negation (Cooper & Ginzburg 2015), we show how a wide range of functions of laughter can be deduced. These include signalling irony, dismissing the seriousness of an assertion, question, or suggestion, and scare quotation. This view of laughter also captures straightforwardly the potential for misunderstanding/repair associated with laughter, given the need to resolve in context both laughable and topos. It also captures the “hyper-intensional” nature of humor that does not e.g., survive translation or synonymous paraphrase, in exactly the same way as the hyper-intensionality of repair processes. This requires adopting independently motivated assumptions about the nature of the input to semantics/pragmatics, namely rich, multi-dimensional representations of utterances. This assumption is not generally assumed in most other semantic/pragmatic frameworks.

In order to explicate the requisite notion of pleasantness whose importance for laughter has been emphasized by Morreall, we build on existing work in cognitive psychology and artificial intelligence. We extend the representations of KoS so that they incorporate the outputs of appraisal reasoning/emotion construction. This allows us both to capture the incrementation of a laugher’s public level of pleasure, as well as deduce functions of laughter such as affiliation, empathetic feedback, and superiority. Using this extension of KoS, we have sketched in broad terms how our approach extends to other non-verbal social signals such as smiling, sighing, and frowning for which the arguments we offer about the content-fulness of laughter extend straightforwardly.

Given that these signals are considered intentionally produced alternatives to each other (and to verbal signals), we can also capture their potential to give rise to conversational implicatures.

We have mentioned that the current approach can deduce various potential functions that laughter has. In fact, our view of laughter meaning means that we do not assume the existence of a limited set of discrete functions that are associated with laughter; in principle, distinct laughter episodes can give rise to an unbounded number of distinct inferences, as assumed, in both constructionist and appraisal views of emotional episodes. We have not addressed attested functions here, but Mazzocconi et al. (2020) have developed a taxonomy for the functions of laughter building on the two basic meanings here. They utilize a taxonomy with four subtypes: pleasant incongruity (cases in which a clash between the laughable and certain background information is perceived as witty, rewarding and/or somehow pleasant), social incongruity (situations involving a clash between social norms and/or comfort and the laughable), pragmatic incongruity (cases when there is a clash between what is said and what is intended), and pleasantness (cases lacking incongruity where a sense of pleasantness/affiliation is either felt or displayed towards the interlocutor.). A corpus study using this taxonomy based on examination of 1072 laughs (289 instances in English (drawn from the British National Corpus (BNC)), 562 instances in French, and 221 in Chinese (the latter two drawn from the multilingual DUEL corpus (Hough et al. 2016)) achieves very high coverage (> 99%).

At this point, a natural question to ask is: have we shown that laughter (and its close relatives smiling, frowning, sighing etc) belong to the grammar? We do not assume that this is a question that can be answered straightforwardly, not least because of potential disagreements about what constitutes the grammar. Over the last few years, several works have appeared detailing the view that grammars should be viewed as systems that classify an utterance as it occurs in conversation see e.g., (Ginzburg 2012; Ginzburg & Poesio 2016; Kempson et al. 2016; Cooper 2020). Thus, Ginzburg & Poesio (2016). argue that phenomena such as disfluencies, non sentential utterances, quotation, and co–speech gestures are as rule-governed as binding, control, and dislocation—traditional sentence-level phenomena captured in formal grammars. Given the existence of formal accounts for all these conversational phenomena within frameworks such as KoS (Ginzburg 2012), PTT (Poesio & Rieser 2010), SDRT (Asher & Lascarides 2003), Dynamic Syntax (Kempson et al. 2016), and other related frameworks, this suggests the need for a new view wherein grammar is a means for directly characterizing speech events, abolishing the performance/competence distinction (though recasting this in a way that allows maintaining a distinction between the task of describing the linguistic phenomena from the task of describing how they get processed.).

In considering whether laughter and its non-verbal cousins merit inclusion in the grammar in the above sense, one would presumably consider criteria such as the following, all of which all the above phenomena such as disfluencies, non-sentential utterances, quotation, and co-speech gestures pass:52

With respect to placement, one very influential view due to Provine (1993) has been that laughter always follows the laughable and only occurs between spoken utterances; Vettin & Todt (2004) offer a more nuanced account, but assume adjacency between laughter and laughable and exclude laughs that occur in the middle of or overlap with an utterance. Mazzocconi et al. (2020) demonstrate (for French and Chinese in the DUEL corpus and English in the BNC) that only 72% of laughs immediately follow their referents. Instead, the laugh can occur before, during or after the laughable with wide time ranges. Strikingly, they demonstrate statistically significant differences between the three languages regarding the positioning of laughter in relation to its laughable. An earlier result though on a smaller scale is due to Gavioli (1995), who found that laughter used to remedy social incongruity—where a bookseller had to provide a dispreferred response to a client—occurred by and large turn initially for English (n=16, 75%) whereas turn finally in Italian (n=20,90%). To this one can add work that describes carefully the positioning of a variety of non-verbal signals such as sighs (Hoey 2014) and sniffs (Mondada 2020). At the same time, it is clear that a detailed formal account of placement and form/meaning/function correlations is still very open for laughter and other conversational facial gestures, in particular on the extent of cross-linguistic variation in this respect and its basis.53

The neuroscientific study of laughter is very active: including locating multiple sites in the brain of activation for laughter and smiling (Szameitat et al. 2010), and the demonstration that there is different brain activity underlying subjects’ ability to distinguish “genuine”/spontaneous’ from “fake”/“strategic” laughter (Lavan & McGettigan 2016). However, for the moment, there has been little work on laughter processing in spontaneous conversation which would indicate how this processing relates to other elements of conversation viewed as grammar internal.

The fact that apes possess laughter–like calls (Ross et al. 2009) raises various questions about the cognitive and semantic relationship between such calls and human laughter (and smiling). These include: (i) Does chimpanzee laugh face anticipate illocutionary act seriousness cancellation laughter with humans, as already suggested by the highly prescient Bateson (1955)? More generally, (ii) do apes have incongruity laughter? This is suggested, for instance, by observation of laughter during play (tickling and rough-and-tumble) (Van Hooff & Preuschoft 2003; Davila-Ross et al. 2011), and by anecdotal data such as https://www.youtube.com/watch?v=OLrYzY3jVPY, where an orangutan apparently laughs at a magic trick. Given the semantic complexity of incongruity, as discussed here extensively, this would potentially require rethinking existing views of non-human cognitive capacities, whether in the wild or for non-humans living in close contact with humans (Griebel et al. 2016).