I am a faculty member in computer and cognitive sciences at the University of Toronto. I direct the Cognitive Lexicon Laboratory where jointly with my students and collaborators we explore the intersection of language, cognition, and computation.
Natural language utilizes a finite vocabulary to express an infinite array of ideas. I am interested in how language users adapt the lexicon to convey emerging meanings over short (e.g., in child language development) and long (e.g., in historical language evolution) time frames, and whether there are shared computational principles and mechanisms in the growth of the lexicon across timescales. My recent focus has been on understanding the phenomena of semantic change and lexical innovation, particularly how words extend or combine to acquire new meanings, and the extent to which computational models can replicate the underlying cognitive processes.
In related projects, I have worked on the computational analysis of crosslinguistic structures. I also develop computational methods for exploring the relations of language with other domains such as morality.
Evolution and development of the lexicon
- Li, J., Armstrong, B.C., and Xu, Y. (in press) Discovering regularity and mechanisms of word sense acquisition in childhood. PNAS.
- Fishkin, M., Chang, S., and Xu, Y. (2025) From Human child to Grey Parrot: Exploring a common model of word meaning extension across species. Cognitive Science, 49(10), e70129.
- Yu, L. and Xu, Y. (2025) Infinite mixture chaining: An efficiency-based framework for the dynamic construction of word meaning. Open Mind, 9, 1-24.
- Xu, A., Kemp, C., Frermann, L., and Xu, Y. (2024) Word reuse and combination support efficient communication of emerging concepts. PNAS, 121(46), e2406971121.
- Ramezani, A., Stellar, J.E., Feinberg, M., and Xu, Y. (2024) Evolution of the moral lexicon. Open Mind, 8, 1153-1169.
- Brochhagen, T., Boleda, G., Gualdoni, E., and Xu, Y. (2023) From language development to language evolution: A unified view of human lexical creativity. Science, 381(6656), 431-436.
- Sun, Z., Zemel, R., and Xu, Y. (2021) A computational framework for slang generation. TACL, 9, 462-478.
- Xu, A., Stellar, J.E., and Xu, Y. (2021) Evolution of emotion semantics. Cognition, 217, 104875.
- Ferreira Pinto Jr., R. and Xu, Y. (2021) A computational theory of child overextension. Cognition, 206, 104472.
- Habibi, A.A., Kemp, C., and Xu, Y. (2020) Chaining and the growth of linguistic categories. Cognition, 202, 104323.
- Ramiro, C., Srinivasan, M., Malt, B.C., and Xu, Y. (2018) Algorithms in the historical emergence of word senses. PNAS, 115(10), 2323-2328.
- Xu, Y., Malt, B.C. and Srinivasan, M. (2017) Evolution of word meanings through metaphorical mapping: Systematicity over the past millennium. Cognitive Psychology, 96, 41-53.
- Xu, Y., Regier, T. and Malt, B.C. (2016) Historical semantic chaining and efficient communication: The case of container names. Cognitive Science, 40(8):2081-2094.
Analysis of crosslinguistic structures
- Fugikawa, O., Hayman, O., Liu, R., Yu, L., Brochhagen, T., and Xu, Y. (2023) A computational analysis of crosslinguistic regularity in semantic change. Frontiers in Communication, 8:1136338.
- Hahn, M. and Xu, Y. (2022) Crosslinguistic word order variation reflects evolutionary pressures of dependency and information locality. PNAS, 119(24), e2122604119.
- Xu, Y., Duong, K., Malt, B.C., Jiang, S., and Srinivasan, M. (2020) Conceptual relations predict colexification across languages. Cognition, 201, 104280.
- Xu, Y., Liu, E., and Regier, T. (2020) Numeral systems across languages support efficient communication: From approximate numerosity to recursion. Open Mind, 4, 57-70.
- Kemp, C., Xu, Y., and Regier, T. (2018) Semantic typology and efficient communication. Annual Review of Linguistics, 4:109-128.
- Ramezani, A., Stellar, J.E., Feinberg, M., and Xu, Y. (2026) Historical reconstruction of human moralization with word association and text corpora. Nature Communications, 17, 3412.
- Ramezani, A., Liu, E., Lee, S.W.S., and Xu, Y. (2024) Quantifying the emergence of moral foundational lexicon in child language development. PNAS Nexus, 3(8), 278.
- Ramezani, A. and Xu, Y. (2023) Knowledge of cultural moral norms in large language models. In ACL.
- Prystawski, B., Grant, E., Nematzadeh, A., Lee, S.W.S., Stevenson, S., and Xu, Y. (2022) The emergence of gender associations in child language development. Cognitive Science, 46, e13146.
- Xie, J.Y., Ferreira Pinto Jr., R., Hirst, G., and Xu, Y. (2019) Text-based inference of moral sentiment change. In EMNLP-IJCNLP.
