Psychological implausibility

Of course, there are coherence theories which do not aim to provide a psychologically plausible account of utterance understanding. As Kroon (1995: 96) puts it,

“The proposed classification of coherence relations may admittedly appear to be artificial, given that in actual discourse no clearcut [sic] boundaries can be observed between the various categories […]. It should be noted, however, that the model serves a rather specific analytical and descriptive goal, and in no way purports to be a full-fledged, general model for the production and interpretation of coherent discourse”.

Put differently, some coherence models aim to give a descriptively adequate account of the product of utterance production, namely texts (Sanders et al. 1992: 3). It may seem, then, that we can make a clean distinction: coherence theories should deal with the product of utterance production, and cognitive theories should deal with utterance production and understanding.

However, there are two complications with this picture. First of all, we have already seen that coherence theories are not descriptively adequate (§2.1.1, §2.1.2). Secondly, many coherence models do purport to be psychologically informed, i.e. to be a psychologically plausible model of how people interpret discourse – most explicitly Sanders et al.’s model (1992, 1993), but also e.g. Mann & Thompson’s RST (Mann & Thompson 1986a, Mann et al. 1989). I have already dealt with the first complication; in this paragraph, I will discuss the second complication – how coherence theories which aim to provide a cognitively realistic account of coherence miss their mark – by way of an analysis of Sanders et al.’s model.

The coherence model of Ted Sanders and colleagues was developed primarily in the 1990s (see especially Sanders et al. 1992, 1993; Knott & Sanders 1998). Like all coherence models, it presumes that discourse is made up of discourse segments related to each other by coherence relations. These coherence relations are not described as relations which are internal to the artifact under consideration (i.e., the text), but as cognitive entities:

“the essential property of [coherence, SZ] relations is that they establish coherence in the cognitive representation language users have or make of a discourse.” (Sanders & Noordman 2000: 38)

According to Sanders & Noordman (2000: 39; also Knott & Sanders 1998: 136), coherence relations should not be conceptualized as “analytic tools” employed by scholars to parse texts, but as psychologically real entities which must be derived by the speaker’s audience if the utterance is to be understood:

“constructing a coherent representation of a text requires that coherence relations can be established between text segments, or rather between the representations readers have of text segments.”

Coherence, then, is a property of the psychological representation which hearers have of discourse (Sanders et al. 1993: 94). The role of DMs, on this view, is to “facilitate” utterance processing – if the coherence relation is made explicit by the presence of a DM, the hearer will be able to construct the speaker-intended psychological representation of the discourse more easily and quickly (Sanders & Noordman 2000: 42). If a DM is not present, the hearer will have to derive the coherence relation by himself, and cognitive effort will be increased (Sanders & Spooren 2007: 926).

As outlined in §2.1.2, Sanders et al. (1992, 1993) propose that coherence relations are derived derivatively, through the interaction of different ‘cognitive primitives’. These cognitive primitives are basic categories of human cognition, which can be in one of two ‘states’ in a given utterance (Sanders et al. 1993: 98). To reiterate, these are:

(19) a. Basic operation: can be causal or additive.

b. Source of coherence: can be semantic or pragmatic. c. Order: can be basic or nonbasic.

d. Polarity: can be positive or negative. (from Sanders et al. 1992: 11)

Coherence relations, on this view, are “composite” in that they consist of different ‘states’ of these cognitive primitives, which interlock to give rise to specific coherence relations (Sanders et al. 1993: 98):

“The interpretation of a coherence relation is considered to be a process of checking the primitives. The result of this checking is the interpretation of the relation between the discourse segments.”13

A causal pragmatic nonbasic positive combination of cognitive primitives, for instance, can result in a coherence relation of ‘Claim-argument’, where the first discourse segment is related to the second as a claim for which an argument is specified in the second segment. If the polarity is changed from ‘positive’ to ‘negative’, we get a ‘Contrastive claim-argument’. If we get an additive semantic positive combination, the resulting relation is a ‘List’. And so on (Sanders et al. 1992: 11).

A first issue for Sanders et al.’s model has to do with the ‘order’ primitive. If the basic operation is ‘additive’, then there is no ‘order’ – that is, it is not ‘basic’ or ‘nonbasic’ in those cases, but just absent. For a ‘List’, in other words, there is no ‘basic’ or ‘nonbasic’ order, as the discourse segments are just added to each other. For the ‘causal’ basic operations, the order does matter – if the order is ‘basic’, we get an Argument-claim, for instance; if all parameters except for the order stay the same, we get a Claim-argument. Surely we can question whether the ‘order’ cognitive primitive is indeed a primitive if it doesn’t matter for about half of all possible combinations.

A second problem occurs when the model is confronted with incoherent discourse which is understandable, or coherent discourse which is not understandable. Note that, on Sanders et al.’s model, cognitive effort will have to be expended in order to construct a coherent model of the discourse – in other words, checking the cognitive primitives, and recognizing the resulting coherence relation which holds between discourse segments, are prerequisites for discourse understanding. In §2.1.5, however, I outlined how not all felicitous discourse is coherent, nor all coherent discourse felicitous. If this is true (and I know of no coherence arguments to the contrary), then this would mean that, in some cases, cognitive effort is expended searching for coherence relations which either do not exist (in the case of incoherent felicitous discourse) or do not lead to utterance understanding (in the case of coherent infelicitous discourse). In both cases, valuable time and effort is wasted looking for something which either doesn’t exist or doesn’t matter.

This would mean that utterance processing would be managed non-optimally and, in a way, very crudely and (pardon the pun) primitively. We would look for cognitive primitives when confronted with any utterance – even those utterances where they aren’t present or do not lead to cognitive rewards (i.e., the speaker-intended interpretation of an utterance). In those utterances where they do occur (i.e., coherent

13 _{Unger (1996: 414) points out that Sanders et al. (1993) leave unexplained how this ‘checking process’ would}

discourse), we would sometimes check for a cognitive primitive which is simply not present (in the case of additive basic operations). Sanders et al. have nothing to say about how to deal with utterances where coherence doesn’t exist or is irrelevant (or where one of the cognitive primitives is irrelevant), but a cognitive system which is as rough-hewn as they assume would seem to require some explanation. It is somewhat akin to a farmer who goes out 365 days a year and walks a mile to check whether he can harvest his crops – on some days, this will be worth it (especially in spring), but most of the days (especially in winter), his effort will be wasted, since his crops will definitely not be growing then. You’d assume that this poor farmer would eventually stop going out for his daily checking process and that he would put in place a different method of monitoring his crops. I use this comparison (admittedly rough-hewn itself) to bring out the point that Sanders et al. provide no plausible method for excluding considerations of coherence where they are irrelevant or non-existent, and that they hence provide a cognitively inelegant model of utterance processing.

A cognitively plausible model of utterance processing would have to be more robust than Sanders et al.’s – it would have to be able to deal with all utterances, coherent or not. The easiest way to do this would seem to be to ignore the notion of coherence altogether (in other words, to not go out and check our crops every day) – this is possible, as we have seen, since coherence is neither a necessary nor a sufficient prerequisite for discourse understanding. If coherence is excluded from the discussion, there would be no need to posit cognitive rules about how and where to ignore considerations of coherence. Instead, the model would cover all utterances which are understandable (whether they are coherent or not), and would exclude non- understandable utterances (i.e., nonsense, unfamiliar jargon, irrelevant utterances, and so on).14

A coherence theorist may raise an objection here. He or she may accept that coherence is not a given (i.e., that there are utterances which are incoherent but understandable or coherent but non-understandable), but that it still needs to be checked for all the same. If an utterance is coherent, then a cognitive process is set in motion whereby the discourse is checked for (for example) cognitive primitives, and a coherence relation is derived. If an utterance is non-coherent, then this cognitive

14 _{Sanders et al. (1992: 16-21) present experimental evidence in favor of their hypothesis that their cognitive}

primitives and coherence relations are psychologically real entities. However, these experiments let their subjects choose a certain coherence relation from a menu of possible relations for each different utterance. There is, of course, no causality here – the fact that people have coherence-based intuitions about how discourse is related, does not mean that coherence relations are cognitively real entities which lead to utterance understanding. Put differently, these types of experiments presuppose that coherence relations are psychologically real, which is exactly what we would like to know.

process would remain dormant. In this way, cognitive effort would be limited to checking for coherence, and the more cognitively effort-intensive process of deriving a coherence relation and a coherent interpretation would only be set in motion if certain expectations were met. This objection (if it exists – I have not encountered it) would be psychologically implausible as well. First of all, this is not a cognitively efficient way of handling stimuli, as we have seen – presumably, we would assume that fine-tuned cognitive systems function elegantly, or, at the very least, that they would not just throw cognitive resources against the proverbial wall to see what sticks. Secondly, and relatedly, this position assumes that a hearer is ‘unboudedly rational’ (Gigerenzer & Todd 1999: 8-10). A hearer would have to first establish whether a text is coherent in order to deduce whether it is worth the effort of looking for coherence (i.e., whether the benefits (the knowledge that the text is coherent) outweigh costs (putting effort and time into deriving that knowledge)). But this is, of course, a catch-22: you can only conclude if something is worth any effort by putting effort into deriving the conclusion whether it is worth any effort. Not only is this conclusion paradoxical, it also leads to an infinite regress – you’d have to consider the cost of putting any effort into deriving a conclusion, but then you’d have to put effort into considering whether this first effort is worth the effort, and so on (id.: 11). This cannot be how our cognitive systems work; realistically, our minds have to “make decisions under constraints of limited time and knowledge” (id.: 5). They are boundedly rational – they know where to search, when to stop and how to make decisions about the information they process (Gigerenzer & Selten 2002: 8). Coherence models, on the other hand, implicitly assume that our minds are unboudedly rational – that they have unlimited time and resources to process information and derive inferences (Gigerenzer & Todd 1999: 8-10). It is cognitively wasteful to look for coherence in this unboudedly rational sense.15

It is also cognitively wasteful to look for coherence in coherence models which do not propose ‘cognitive primitives’. RST, for instance, also assumes that their ‘rhetorical relations’ are psychologically real, i.e. real “cognitive entities” (Sanders & Noordman 2000: 39).16 _{On this view, coherence relations are themselves ‘cognitive primitives’}

(although they are not labeled as such) – i.e., cognitively primary and not derivative like in Sanders et al.’s model (Sanders et al. 1993: 97). This presents another problem: if the hearer needs to derive the speaker-intended relation in order to derive the speaker-

15 _{Lenk (1998b: 19) also raises the question as to “whether online production of spoken discourse leaves the}

participants in conversation enough time to process incoming information according to” elaborate taxonomies such as those proposed in Sanders et al.’s model.

16 _{Hobbs’ model (e.g. 1979, 1985) also assumes that coherence relations are real cognitive entities (Knott &}

Sanders 1998: 137-138; Schourup 2011: 2114). Redeker (2000: 239) simply rejects Sanders et al.’s notion that coherence relations are “real mental entities” – according to her, they are “theoretical constructs”.

intended interpretation, how is he able to find the speaker-intended relation? Mann & Thompson assume that the hearer is able to apply contextual information (or ‘background assumptions’) in order to recognize the correct coherence relation, but provide no further information as to how the hearer would be able to do this (Blass 1993: 92). As we have seen (§2.1.1), once context is admitted to the coherence party, it can handle proceedings much more efficiently – we can just cut out the coherence middleman and propose a realistic account where the right contextual information leads to the speaker-intended interpretation of an utterance without the mediation of coherence relations. But there are further questions raised by Mann & Thompson’s proposal. For one, does the hearer search through all contextual assumptions available to him – prior utterances in the discourse, encyclopaedic knowledge, visual and auditory cues from his surrounding physical context, and so on –, and then apply the relevant ones to the process of deriving the correct coherence relation? Again, this would be unboudedly rational – i.e., too effort-intensive and time-consuming. How, then, does he select the speaker-intended contextual assumptions, and how does he know when to stop searching for further contextual assumptions? Coherence analysts are silent on this topic, but it is an essential part of any psychologically realistic approach to utterance understanding. Selecting the right contextual assumptions is what is known as a ‘computationally intractable’ problem (see e.g. Cherniak 1981; Barrett & Kurzban 2006: 629-630; Carruthers 2006a: 14; also Samuels (2000) for more general discussion), and, in cognitive theories of utterance understanding more specifically, the ‘frame problem’ (see also Apperly 2011: 9; Blakemore 1988: 236):

“Cognitive systems, such as ourselves, cannot go through everything they know in order to determine what information is going to be relevant for a particular inference, since this would be an infinite task. Thus, the frame problem is the problem of putting a "frame" around the set of beliefs that need to be brought to bear in the processing of new information.” (Chiappe & Kukla 1996: 529)

This problem is, again, bound up with the notion of bounded rationality – people simply do not have the time or the resources to go through everything they know (and see and hear and so on) in order to derive an interpretation which may or may not be better than one which takes much less context into account. If a cognitive system would take all the contextual assumptions it has available into account when processing an utterance, the process would become computationally intractable: there would simply be too many possible interpretations to compute given the limited time and resources available to the cognitive system (Gigerenzer 2008: 21).

However, let’s say the hearer is somehow able to home in on certain contextual assumptions, and manages to apply them to derive a coherence relation. How does he know that this is the speaker-intended one? To use Mann et al.’s (1989) list of coherence

relations, let’s say the hearer decides that a relation of Elaboration holds between two discourse segments. How does he know that another relation (e.g., Restatement) would not fit better? Why would he not check all coherence relations to see which one would fit best? After all, no stopping rule is proposed – no coherence model, to my knowledge, proposes how and why people stop looking for an optimal coherence relation, and how they limit their search for a suitable coherence relation (see Gigerenzer & Selten 2002: 8; Gigerenzer 2008: 24). This does not even take into account that there is no consensus on which coherence relations exist, and that, consequently, we do not know which or how many relations would have to be checked before stopping (cf. Knott & Sanders 1998: 140). Let’s assume, then, that we do not check all coherence relations when interpreting a coherent utterance. Do we then stop optimizing our search for a coherence relation when a certain threshold is passed? If so, what is this threshold, and how would it be described cognitively? Would this be a conscious process, where the hearer calculates when to stop, or would it happen automatically? These questions remain unanswered.17

Coherence theories, then, do not seem to be psychologically plausible – if anything, they seem to assume that discourse comprehension works in a cognitively wasteful way. Yet there is model of utterance understanding which can deal with all types of acceptable utterances (whether they are coherent or not), which does have a stopping rule, and which does deal with the frame problem. In addition, it assumes that utterance understanding is a ‘fast and frugal’ process in Gigerenzer & Todd’s (1999) sense – it derives interpretations with a minimum of time and effort expended. This model is Sperber & Wilson’s (1995²) relevance theory, and it will be discussed in more detail later on.

I have attempted to show in this chapter that discourse coherence is a descriptively inadequate and psychologically implausible way of looking at language – and, as such, is

17 _{Note that we have already discussed one possible answer before, when discussing whether hearers/readers}

looked for coherence when processing utterances. I argued that this could not be true – the hearer would first have to establish whether a given utterance is coherent before deciding whether that utterance was worth the effort of checking for coherence. The same objection applies here – a possible answer to the preceding questions could be ‘well, the hearer should stop optimizing his search for a coherence relation when it is more cost-intensive to keep searching than it is to derive the possible benefit you may derive by continuing your search’. On this view, the hearer would still be caught in an unboudedly rational catch-22: he would first have to know whether the possible solution would be worth the effort before putting in the effort to derive it. There are also opportunity costs – our hearer would have to weigh the costs and benefits of continuing his search against the costs and benefits of doing something else. In turn, this leads to another infinite regress: our hearer would have to weigh whether his weighing of the costs and benefits of continuing his search against the costs and benefits of doing something else is worth the effort, and then weigh that weighing of the weighing, and so on (Gigerenzer & Todd 1999: 10-11).

a suboptimal framework for analyzing DMs.18 _{I have, then, demonstrated in what sense}

DMs cannot be connective (the coherence sense), but not what the alternative would be. The reason for this is that this alternative is bound up with a very specific approach to non-truth-conditional meaning – put differently, non-truth-conditional meaning is a crucial element in the account of DMs I am constructing.

Unfortunately, non-truth-conditionality has received far less attention than connectivity in DM research. This is probably due to the fact that most scholars working on DMs take a functional approach – they describe DMs in terms of what they do, not what they are.19 _{They are commonly regarded as items which function have ‘pragmatic}

functions’ or ‘pragmatic meaning’ and are, hence, an object of interest for pragmaticists,