Logic in Semantic Universals (2022-2025) is a 4-year project funded by the UKRI Future Leaders Fellowship. The goal of the project is to uncover what underlies cross-linguistic generalisations in the semantics of logical vocabularies by bringing together theoretical and methodological insights from formal semantics and evolutionary linguistics.
The project team will consist of Wataru Uegaki (PI), two postdoctoral researchers (hired at different stages of the project), and two research assistants. The project will also involve collaboration with a number of researchers, including: Jennifer Culbertson, Antonella Sorace (Edinburgh), Jakub Szymanik, Floris Roelofsen (Amsterdam) and Malte Zimmermann (Potsdam).
Despite the immense diversity of human languages, linguists have discovered robust common properties shared across them. Since such cross-linguistic universals are likely to provide us with a window into the core cognitive basis of the linguistic ability we possess as a species, understanding their nature is a fundamental goal in the scientific study of human language. Research on cross-linguistic universals has been especially fruitful in lexical semantics, i.e. the study of word meanings.
However, despite the rich empirical landscape, a fundamental question still remains open: what, if any, core properties of human language the semantic universals are rooted in. An influential hypothesis states that semantic universals are explained by a functional principle favouring a linguistic system that supports efficient communication (Kemp et al., 2018). Importantly, this principle is highly general, and suggests that seemingly disparate semantic phenomena may in fact reflect a unified functional pressure. However, researchers disagree on whether such a general functional perspective alone explains the wide range of semantic universals observed in the literature. A distinct view is typically favoured in theoretical linguistics, according to which specific grammatical knowledge encoded in our language faculty—which cannot be reduced to functional pressures— plays an important role in the explanation of semantic universals (e.g., Keenan & Stavi, 1986; Chierchia 2013).
There is a gap in the current research that hinders us from resolving this tension. While the cognitive basis for the universal patterns in the meanings of content words (such as colour and kinship terms) has been thoroughly investigated, there has been scant research into the cognitive basis of the universals in the meanings of logical words. The situation is pressing because logical words provide the scaffolding for productivity, the central design feature of human language that sets it apart from the communication systems of other species (Hockett 1960); with the help of logical words like and, we are able to produce an infinite number of sentences. Since these words set human languages apart from animal communication systems, it is plausible that they reflect specialised features of our language faculty, rather than domain-general functional pressures. Despite this importance, however, the cognitive basis underlying the universal properties of logical words has yet to be thoroughly investigated, due to lack of a unified semantic theory for relevant meanings and methodological difficulty in designing experiments to test distinct hypotheses.
Recent theoretical and methodological developments in linguistics and cognitive science finally enable us to fill this gap. Theoretically, advances in semantic theories now make it possible to analyse the meanings of various logical words in a unified framework, making it possible to state potential generalisations holding in logical vocabularies in precise ways (Kratzer, 2012; Gärdenfors, 2014; Ciardelli et al., 2018; Chemla et al., 2018). This includes the PI’s own theoretical contribution (Uegaki, 2019), which has enabled a unified formal analysis of the meanings of various clause-embedding predicates. These theoretical advances come hand in hand with methodological developments in cross-linguistic data collection. In addition, evolutionary linguistics has shown that distinct aspects of linguistic communication can be parcelled out and investigated systematically in the lab and computer simulation, using experimental paradigms involving learning and transmission of artificial languages (Kirby et al., 2015; Culbertson & Kirby, 2016). These methods have only just begun to be used to explore semantics.
In this project, I will make use of these recent advances in semantics and evolutionary linguistics to resolve the research question above: why the observed semantic universals exist and what, if any, core properties of human language or cognition they are rooted in. Not only will our research address one of the most fundamental research questions in linguistics, but it will also integrate semantics and evolutionary linguistics at an unprecedented scale.
The project involves the following four stages of research.
S1. Through cross-linguistic data collection, we will empirically evaluate universals in logical vocabulary hypothesised in the literature. Moreover, we will seek to discover new universals. We consider both absolute universals and statistical tendencies.
S2. We will construct semantic/pragmatic theories that explain the typology resulting from the data collection, based on two distinct hypotheses: Communicative Efficiency and Natural Logic.
S3. We will test the theories constructed in 2 based on behavioural and computational modelling experiments employing artificial-language learning.
S4. We will extend the project in view of bilingualism research based on the results of Stage 3 to investigate aspects of language use shown by non-native language learners.
At the end of the project, we will pursue a theoretical synthesis based on the overall theoretical and experimental findings, with the aim of reaching a conclusive answer to our research question, i.e., what core properties of human language or cognition are the semantic universals rooted in.