Linguistic Complexity

by

Bernd Kortmann, Verena Schröter

• LAST REVIEWED: 24 January 2025
• LAST MODIFIED: 15 January 2020
• DOI: 10.1093/obo/9780199772810-0254

Introduction

Linguistic complexity (or: language complexity, complexity in language) is a multifaceted and multidimensional research area that has been booming since the early 2000s. The currently dominant research strand, which takes center stage in the present article, is concerned with structural complexity of entire languages, dialects, and varieties as such (so-called global linguistic complexity) or individual subsystems thereof (local linguistic complexity, as in phonology, inflectional morphology, syntax). In the context of these research lines the issue of how to measure structural complexity has come to play a prominent role, as only consistently applied complexity metrics, both from a purely system- (or langue-) perspective and from a usage- (or parole-/performance-) perspective, allow typological or cross-varietal comparisons. This comparative dimension was indeed the trigger of the renewed interest in linguistic complexity and complexity metrics when in 2001 a heated debate was launched challenging the so-called equi-complexity dogma (or: axiom). Following up on Sapir’s vivid analogy that “both simple and complex types of language of an indefinite number of varieties may be found spoken at any desired level of cultural advance” and thus “when it comes to linguistic form, Plato walks with the Macedonian swineherd, Confucius with the head-hunting savage of Assam” (see Sapir 1921, cited under Equi-Complexity Debate), this dogma had been entertained throughout most of the second half of the 20th century and postulated that, structurally speaking, the grammars (i.e., morphology and syntax) of all languages are, on balance, equally complex. The basic idea behind this assumption, which is all it really was (as it had originally been formulated without any systematic comparison or quantitative backing), was that in a comparison of any two languages higher and lower degrees of complexity in different sub-domains of morphological and syntactic structure will ultimately balance each other out. This assumption remained unchallenged throughout the 20th century, almost acquiring (more implicitly than explicitly, though) the status of an established truth, or even dogma. Only with linguistic sub-disciplines like language typology, Creolistics, corpus linguistics or dialectometry gaining full momentum, coupled with the strong quantitative turn since the 1990s, has the equi-complexity axiom come back in the limelight and can be investigated with the sophisticated theoretical and methodological toolkit of 21st-century linguistics. Besides structural (or: absolute) complexity, other major aspects of linguistic complexity and complexity metrics that have been discussed in the research literature of the last twenty years can be lumped together under the heading of user-based (or: relative) complexity. On the one hand, this includes the processing and interpretive efforts the natural language user needs to engage in when assigning meanings and functions to certain structural elements, patterns, and rules (in isolation or in actual usage) of their native or a different language or dialect. On the other hand, there are various lines of complexity research that focus on the learner, both the first-language child learner and, especially, the second or foreign-language adult learner. This take on linguistic complexity (discussed under the heading of learner complexity) is dominant in Second Language Acquisition (SLA) research but prominent, too, in relevant research informed by sociolinguistic and contact-linguistic perspectives. Finally, it is evident that for both structural and user-based complexity there is also research adopting an evolutionary (language change) or developmental (ontogenetic) perspective.

Edited Volumes

As a highly multifaceted phenomenon, the quickest way to get an overview of 21st-century thinking about linguistic complexity and how to measure it is to consult the edited volumes cited in this section. Kortmann and Szmrecsanyi 2012; Miestamo, et al. 2008; and Sampson, et al. 2009 are top of the league in this respect. Like most of the complexity research in the course of the last twenty years, these three share a broadly functional approach, focus on complexity in morphology and syntax, and cover central aspects of definition, classification, theory, methodology, and important reflections (often coupled with illuminating case studies) on linguistic complexity and its evolution from the point of view of language contact, language acquisition (in early and adult age), and societal structure. Also included in these volumes are instructive critical discussions and research reviews of linguistic complexity, proposals for various kinds of complexity metrics, and the equi-complexity dogma. The other edited volumes in this section have either a somewhat narrower or theoretically different outlook on linguistic complexity. Baechler and Seiler 2016 zooms in on the morphology and syntax of dialects, in particular, with a special interest in the areal and sociolinguistic conditions fostering structural complexity growth, while the contributions in Faraclas and Klein 2009 offer comparative as well as single-language accounts of both phonological and morphosyntactic complexity in Pidgins and Creoles. Baerman, et al. 2015, written by major representatives of the Surrey Morphology Group, famous for its many groundbreaking works within language typology, is restricted to studies and reflections on (largely inflectional) morphology. Syntactic complexity, traditionally defined on a phrasal, clausal, and sentential level, is what is exclusively addressed in Givón and Shibatani 2009, primarily from a diachronic and evolutionary point of view, on the one hand, and a cognitive and neurological point of view, on the other. Not dissimilar in scope and outlook, Mufwene, et al. 2017 addresses linguistic complexity from two overarching perspectives: the (structural) evolution of language and languages and the ontogenetic development of language. The hallmark of Newmeyer and Preston 2014 is its pointedly formalist take on linguistic complexity and its measurement compared with the bulk of the complexity literature.

• Baechler, Raffaela, and Guido Seiler, eds. 2016. Complexity, isolation, and variation. Linguae & Litterae 57. Berlin and Boston: De Gruyter.

  This slim volume brings together areal typological and, especially, dialectological studies. Two papers offer new insights into methods of measuring morphological and syntactic complexity, while most of the other papers explore in one way or another the sociolinguistic conditions leading to either complexification (notably as a result of the isolation of speech communities) or simplification (notably as a result of intense contact between languages or dialects).

• Baerman, Matthew, Dunstan Brown, and Greville G. Corbett, eds. 2015. Understanding and measuring morphological complexity. Oxford: Oxford Univ. Press.

  Two helpful scene-setting papers present different approaches to (measuring) morphological (i.e., especially paradigmatic) complexity, such as Sagot’s (unpublished) distinction of counting-based, entropy-based, and description-based morphological complexity (metrics) and a Neo-Sapirean account of major dimensions of morphological complexity relevant for language typology. Two sets of papers follow: the first one offers largely formal analyses of inflectional morphological complexity in different (non-European) languages, while the second one focuses on computational techniques for measuring complexity.

• Faraclas, Nicholas, and Thomas B. Klein, eds. 2009. Simplicity and complexity in Creoles and pidgins. London: Battlebridge Publications.

  Essentially, the volume is designed to test McWhorter’s forceful simplicity hypothesis for pidgins and Creoles, and, more fundamentally, the usefulness of operating with notions such as simplicity and complexity as hitherto applied. Overall, there is agreement that this usefulness is limited in Creolistics and that there are also many features indicative of complexification, in phonology as in morphosyntax, in Creoles as in prototypical pidgins.

• Givón, Talmy, and Masayoshi Shibatani, eds. 2009. Syntactic complexity: Diachrony, acquisition, neuro-cognition, evolution. Amsterdam: John Benjamins.

  Two leading typologists and functional grammarians have compiled almost twenty case studies in a wide range of languages addressing syntactic complexity both on the level of the simple sentence (from words via phrases) and the complex sentence (from simple via paratactic to hypotactic, or embedded, clauses). The genesis of complexity is explored diachronically, ontogenetically and, perhaps most innovatively, from the perspectives of neuro-cognition and brain evolution. (See also Givón 2009 in Monographs.)

• Kortmann, Bernd, and Benedikt Szmrecsanyi, eds. 2012. Linguistic complexity. Second language acquisition, indigenization, contact. Berlin and Boston: De Gruyter.

  Starting out from a concise research review and an outline of the specifically Freiburg (Germany) research program on complexity metrics, this collection brings together three strands of research under the unified perspective of factors conditioning absolute and relative complexity in the grammars of varieties of English and English-based pidgins and Creoles around the world. These strands are language and dialect contact (including Creolistics), adult language acquisition, and indigenization (in L2 varieties of English).

• Miestamo, Matti, Kaius Sinnemäki, and Fred Karlsson, eds. 2008. Language complexity: Typology, contact, change. Amsterdam and Philadelphia: Benjamins.

  The title says it all: one of the classic volumes on a broad range of aspects of linguistic complexity, starting out with two useful perspectivizing papers, one by Kusters, the other by Miestamo. The volume offers single-language accounts but also studies of entire language families or structural types (e.g., isolating languages). Separate from the section on language contact and change, there are four papers exclusively concerned with pidgins and Creoles.

• Mufwene, Salikoko S., Christophe Coupé, and Francois Pellegrino, eds. 2017. Complexity in language: Developmental and evolutionary perspectives. Cambridge, UK: Cambridge Univ. Press.

  This rather thought-provoking volume does not content itself with trying to offer a true understanding of language complexity in the context of complexity research. In its focus on evolutionary and developmental perspectives on language complexity it draws on insights from social science, social cognition, and cultural and brain evolution. Several papers are concerned with modeling. Among the more strictly linguistic—or structure-oriented—papers, complexity both in morphosyntactic and phonological systems is investigated.

• Newmeyer, Frederick J., and Laurel B. Preston, eds. 2014. Measuring grammatical complexity. Oxford: Oxford Univ. Press.

  The research literature on metrics for the complexity of a language’s grammar is clearly dominated by broadly functional accounts. By contrast, this volume offers a decidedly formalist view. For learning more about this perspective, see especially the editors’ introduction and the chapter by Hawkins, which are illuminating reads.

• Sampson, Geoffrey, David Gil, and Peter Trudgill, eds. 2009. Language complexity as an evolving variable. Oxford: Oxford Univ. Press.

  The overarching topic of this volume is a critical engagement with the equi-complexity claim (or even: dogma, axiom). Contributions are from different theoretical and methodological angles, based on largely morphological and syntactic data from a broad range of languages and dialects. Offers arguments from typology, language variation, and language diachrony against the view that all languages are equally complex.