Relevance theory and communication atypicalities

The early 1980s witnessed increasing interest by clinicians in assessing and treating people who, while possessing relatively intact structural language, nonetheless exhibited atypical communicative skills. The decade saw the first serious attempts at the characterization of pragmatic disorders, paving the way for the ultimate development of theories which addressed pragmatic difficulties in adults and children.
In those first attempts to identify symptoms of pragmatic impairment, clinicians were eager and willing to use key concepts introduced by the new, so-called ‘ordinary’ language philosophies of Austin, Searle and Grice. Their enormous influence was best realized in one of the early studies by McTear (1985), where a 10-year-old boy’s poor conversational skills were analyzed in terms of his failure to understand the interlocutor’s indirect speech acts, presupposition, and his violation of the conversational maxim of quality (by contributing inconsistent and misleading information to the exchange). As practical eclecticism became more the norm among clinical practitioners, the seeds of a more sophisticated integration of practice with theoretical developments were sown. Since the mid-1990’s, these frameworks have been Sperber and Wilson’s (1995) Relevance Theory, and approaches based around Theory of Mind (ToM) theories (see Premack & Woodruff, 1978; also Langdon & Coltheart, 1999; Tager-Flusberg, 2000). These two dominant cognitive frameworks which have been increasingly associated with developmental pragmatics in Autism Spectrum Disorders (ASDs) children and adults. Pragmatic language impairments are commonly reported features of clinical populations with acquired disorders, too (for a review of earlier RT studies on right hemisphere damage and traumatic brain injury, see Leinonen & Ryder, 2008; for a recent account, see Jagoe & Wharton, 2021). Over the last three decades, relatively fewer studies, compared to developmental work, used relevance theory’s model of language comprehension to investigate meaning communicated verbally and non-verbally in aphasic and schizophrenic patients. Early studies were inspired by developmental work, as in the case of Mitchley et al. (1998) who followed Happé’s (1993) pioneering work on irony comprehension in young people with autism, in concluding that schizophrenic patients, too, are impaired in their appreciation of the mental states of others.
In this chapter, we first offer a brief introduction to relevance theory, with emphasis on recent developments attempting to integrate non-propositional, yet elemental aspects of verbal and non-verbal communication. We then review early and latest studies on developmental and acquired disorders which used the relevance theoretic framework. One advantage of using a more rigorous theoretical structure to describe behavioural problems in an explicit way is to explain why certain strengths and competencies have grown in some populations and not in others, and why certain abilities have expanded while others have stagnated or declined. The integration of material from clinical pragmatics can also importantly push the boundaries of the theory and broaden the domain to which its insights can be applied.