Linear grammar as a possible stepping-stone in the evolution of language

Abstract

We suggest that one way to approach the evolution of language is through reverse engineering: asking what components of the language faculty could have been useful in the absence of the full complement of components. We explore the possibilities offered by linear grammar, a form of language that lacks syntax and morphology altogether, and that structures its utterances through a direct mapping between semantics and phonology. A language with a linear grammar would have no syntactic categories or syntactic phrases, and therefore no syntactic recursion. It would also have no functional categories such as tense, agreement, and case inflection, and no derivational morphology. Such a language would still be capable of conveying certain semantic relations through word order-for instance by stipulating that agents should precede patients. However, many other semantic relations would have to be based on pragmatics and discourse context. We find evidence of linear grammar in a wide range of linguistic phenomena: pidgins, stages of late second language acquisition, home signs, village sign languages, language comprehension (even in fully syntactic languages), aphasia, and specific language impairment. We also find a full-blown language, Riau Indonesian, whose grammar is arguably close to a pure linear grammar. In addition, when subjects are asked to convey information through nonlinguistic gesture, their gestures make use of semantically based principles of linear ordering. Finally, some pockets of English grammar, notably compounds, can be characterized in terms of linear grammar. We conclude that linear grammar is a plausible evolutionary precursor of modern fully syntactic grammar, one that is still active in the human mind.

Empirical approaches to the study of language evolution

“…The core findings, as taught in introductory courses in linguistics or psychology of language, have been reviewed in detail in many places (e.g., Crystal, 2003;Yule, 2006). Although the correct theoretical and philosophical framework for understanding this picture remains a topic of discussion (see, e.g., the articles by Arbib, 2016;Chomsky, 2016;Jackendoff & Wittenberg, 2016;ScottPhillips, 2016), it all concerns modern humans and thus defines the Bend target^of any evolutionary model, rather than the steps required to get to this point. It is only rather recently that detailed theoretical models of modern language have been used to fuel hypotheses about how language evolved (e.g., Berwick & Chomsky, 2016;Givón, 2002;Hurford, 2011;Jackendoff, 2002Jackendoff, , 2010Scott-Phillips, 2014), though earlier efforts include Bickerton (1990) and Pinker and Bloom (1990).…”

Composition is the core driver of the language-selective network

“…B. Partee, ter Meulen, & Wall, 1990), semantic composition is considered to be a special case of syntactic composition, and syntax determines the meaning of a phrase or a clause. However, according to an alternative perspective, semantic composition can proceed (partially or fully) independently from syntactic structure building (e.g., Jackendoff & Jackendoff, 2002;Jackendoff, 2007;Culicover & Jackendoff, 2006;Culicover, Jackendoff, Jackendoff, et al, 2005;Kuperberg, 2007;Jackendoff, 2010;Jackendoff & Wittenberg, 2017). Baggio (2018) refers to this idea as "autonomous semantics".…”

Multilinear Grammar: Ranks and Interpretations

“…Discussion of the increasing value of number of arguments (so-called one word, two word, n-word utterances) has figured prominently for many decades in studies of first language acquisition, and more recently in discussions of language evolution: from n = 0 (silence is no doubt an also an option for communication), through n = 1 for single word utterances, n = 2 for binary, and n > 3 for the general case. Jackendoff and Wittenberg (2016) suggest that the move from sequences of 2 to sequences of 3 was a qualitative leap in language evolution. Qualitative leaps are also represented by each move beyond sequences of 3, followed by unidirectional recursion and then by the centreembedding generalisation.…”

“…The default procedural plausibility criteria of linear time and finite working memory are at the very least a useful starting point and a potentially falsifiable heuristic benchmark, perhaps even a necessary theoretical core. As complexity increases during the ontogeny and phylogeny of gestural, spoken and written communication, increasingly complex linear patterns appear, from the simplest sound sequences through the basic clausal patterns proposed by Wittenberg and Jackendoff (2014) and Jackendoff and Wittenberg (2016) to the centre-embedding generalisation with its processing problems. We claim that the centre-embedding emerges as a generalisation of non-centre-embedding recursion on the different time scales of spontaneous speech improvisation, of language acquisition, of the history of language change and of language evolution, a claim which is speculative but not implausible, and far simpler and potentially easier to falsify than claims about the triggering of recursion by genetic mutation (though not excluding this possibility).…”