Mission: Impossible Language Models
Paper · 2024 · Julie Kallini, Isabel Papadimitriou, Richard Futrell et al.
Summary
Chomsky and colleagues have argued that LLMs pick up languages humans could never acquire just as readily as natural ones, but almost no experiments have tested this. Kallini et al. tested it by building synthetic "impossible" languages from English text in the BabyLM dataset. The perturbations range from obviously unlearnable ones, such as random or irreversible word shuffles, to subtler rules that linguists treat as impossible, such as placing agreement markers by counting word positions. The languages form three families, *SHUFFLE, *REVERSE and *HOP, and each family has an English-like control. GPT-2 small models were trained on every language and evaluated at many checkpoints during training. The evaluations used test-set perplexity, surprisal on targeted constructions, and causal abstraction analysis. Overall, models trained on natural or near-natural variants learned faster and more completely than those trained on impossible variants. This contradicts the claim that LLMs cannot tell the two kinds of language apart. The study also provides a reusable framework for asking which model biases match human language; the authors point to information locality as a likely candidate.
Key points
- The models are GPT-2 small, trained on modified versions of the BabyLM corpus. Code is available at github.com/jkallini/mission-impossible-language-models.
- The language variants include:
- NoShuffle, NondeterministicShuffle, DeterministicShuffle (seeds s = 21, 57, 84) and LocalShuffle (window w = 3, 5, …)
- the *REVERSE family
- NoHop, TokenHop and WordHop, where the verb marker appears four tokens or words after the verb
- Experiment 1 measured perplexity. Models trained on possible languages reached lower perplexity in fewer training steps.
- Experiment 2 used surprisal comparisons on count-based agreement rules. Models trained on natural languages were more surprised by ungrammatical forms, suggesting they disfavor counting-based agreement.
- Experiment 3 used causal abstraction and interchange intervention accuracy (IIA), averaged over 5 random seeds.
- All *HOP models developed a similar modular way of tracking agreement.
- NoHop reached near-100% IIA by about 1,500 training steps, earlier than TokenHop and WordHop.
Institutions
📚 Shelves 4The field of science this work belongs to (OpenAlex fields).Computer Science · 9,086 worksArtificial Intelligence · 8,889 worksArts and Humanities · 9,296 worksLanguage and Linguistics · 9,206 works
🧭 Topics 1Research subjects and languages the work is about.Language models & pretraining · 1,343 works
Cite
Cite as Julie Kallini, Isabel Papadimitriou, Richard Futrell, Kyle Mahowald and Christopher Potts. 2024. Mission: Impossible Language Models. Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers).
@inproceedings{kallini2024mission,
title = {{Mission: Impossible Language Models}},
author = {Julie Kallini, Isabel Papadimitriou, Richard Futrell, Kyle Mahowald and Christopher Potts},
booktitle = {Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)},
year = {2024},
doi = {10.18653/v1/2024.acl-long.787},
url = {https://doi.org/10.18653/v1/2024.acl-long.787}
}References
- Mostafa Abdou, Vinit Ravishankar, Artur Kulmizev, and Anders Søgaard. 2022. Word order does matter and shuffled language models know it. In Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 6907–6919, Dublin, Ireland. Association f… find
- Matteo Alleman, Jonathan Mamou, Miguel A Del Rio, Hanlin Tang, Yoon Kim, and SueYeon Chung. 2021. Syntactic perturbations reveal representational correlates of hierarchical phrase structure in pretrained language models. In Proceedings of the 6th Workshop on Representation Learning for NLP (RepL4NLP… find
- Johan J. Bolhuis, Stephen Crain, Sandiway Fong, and Andrea Moro. 2024. Three reasons why AI doesn’t model human language. Nature, 627(8004):489–489. find
- Noam Chomsky. 1956. Three models for the description of language. IRE Transactions on Information Theory, 2(3):113–124. find
- Noam Chomsky. 1957. Syntactic Structures. Gruyter Mouton, Berlin, Boston. find
- De Noam Chomsky. 1959. On certain formal properties of grammars. Information and Control, 2(2):137–167. find
- Noam Chomsky. 1965. Aspects of the Theory of Syntax. The MIT Press. find
- Noam Chomsky. 2002. On Nature and Language. Cambridge University Press. find
- Noam Chomsky. 2023. Conversations with Tyler: Noam Chomsky. Conversations with Tyler Podcast. find
- Noam Chomsky, Ian Roberts, and Jeffrey Watumull. 2023. Noam Chomsky: The false promise of Chat-GPT. The New York Times. find
- Bernard Comrie. 1989. Language universals and linguistic typology: Syntax and morphology. University of Chicago press. find
- Gregoire Deletang, Anian Ruoss, Jordi Grau-Moya, Tim Genewein, Li Kevin Wenliang, Elliot Catt, Chris Cundy, Marcus Hutter, Shane Legg, Joel Veness, and Pedro A Ortega. 2023. Neural networks and the Chomsky hierarchy. In The Eleventh International Conference on Learning Representations.
- Jacob Devlin, Ming-Wei Chang, Kenton Lee, and Kristina Toutanova. 2019. BERT: Pre-training of deep bidirectional transformers for language understanding. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies,…
- Javid Ebrahimi, Dhruv Gelda, and Wei Zhang. 2020. How can self-attention networks recognize Dyck-n languages? In Findings of the Association for Computational Linguistics: EMNLP 2020, pages 4301– 4306, Online. Association for Computational Linguistics. find
- Michael Hahn. 2020. Theoretical limitations of self-attention in neural sequence models. Transactions of the Association for Computational Linguistics, 8:156– 171. find
- Jeffrey L. Elman. 1990. Finding structure in time. Cognitive Science, 14(2):179–211. find
- Michael Hahn, Judith Degen, and Richard Futrell. 2021. Modeling word and morpheme order in natural language as an efficient trade-off of memory and surprisal. Psychological Review, 128(4):726–756. find
- Nicholas Evans and Stephen C Levinson. 2009. The myth of language universals: Language diversity and its importance for cognitive science. Behavioral and brain sciences, 32(5):429–448. find
- Michael Hahn, Dan Jurafsky, and Richard Futrell. 2020. Universals of word order reflect optimization of grammars for efficient communication. Proceedings of the National Academy of Sciences, 117(5):2347–2353. find
- Daniel L. Everett. 2012. What does Pirahã grammar have to teach us about human language and the mind? WIREs Cognitive Science, 3(6):555–563. find
- John Hale. 2001. A probabilistic Earley parser as a psycholinguistic model. In Second Meeting of the North American Chapter of the Association for Computational Linguistics.
- Richard Futrell. 2019. Information-theoretic locality properties of natural language. In Proceedings of the First Workshop on Quantitative Syntax (Quasy, SyntaxFest 2019), pages 2–15, Paris, France. Association for Computational Linguistics. find
- Richard Futrell and Michael Hahn. 2022. Information theory as a bridge between language function and language form. Frontiers in Communication, 7. find
- Richard Futrell, Ethan Wilcox, Takashi Morita, Peng Qian, Miguel Ballesteros, and Roger Levy. 2019. Neural language models as psycholinguistic subjects: Representations of syntactic state. In Proceedings of the 2019 Conference of the North American Chapter of the Association for Computational Lingui…
- Lukas Galke, Yoav Ram, and Limor Raviv. 2023. What makes a language easy to deep-learn? find
- Atticus Geiger, Hanson Lu, Thomas Icard, and Christopher Potts. 2021. Causal abstractions of neural networks. In Advances in Neural Information Processing Systems, volume 34, pages 9574–9586. Curran Associates, Inc. find
- Atticus Geiger, Kyle Richardson, and Christopher Potts. 2020. Neural natural language inference models partially embed theories of lexical entailment and negation. In Proceedings of the Third BlackboxNLP Workshop on Analyzing and Interpreting Neural Networks for NLP, pages 163–173, Online. Associati…
- Atticus Geiger, Zhengxuan Wu, Christopher Potts, Thomas Icard, and Noah D. Goodman. 2023. Finding alignments between interpretable causal variables and distributed neural representations. In Proceedings of Causal Learning and Reasoning 2024. find
- Joseph Greenberg. 1963. Some universals of grammar with particular reference to the order of meaningful elements. Universals of Language, pages 73–113. find
- Yiding Hao, William Merrill, Dana Angluin, Robert Frank, Noah Amsel, Andrew Benz, and Simon Mendelsohn. 2018. Context-free transductions with neural stacks. In Proceedings of the 2018 EMNLP Workshop BlackboxNLP: Analyzing and Interpreting Neural Networks for NLP, pages 306–315, Brussels, Belgium. As… find
- Marc D. Hauser, Noam Chomsky, and W. Tecumseh Fitch. 2002. The faculty of language: What is it, who has it, and how did it evolve? Science, 298(5598):1569–1579. find
- Jack Hessel and Alexandra Schofield. 2021. How effective is BERT without word ordering? implications for language understanding and data privacy. In Proceedings of the 59th Annual Meeting of the Association for Computational Linguistics and the 11th International Joint Conference on Natural Language… find
- John Hewitt, Michael Hahn, Surya Ganguli, Percy Liang, and Christopher D. Manning. 2020. RNNs can generate bounded hierarchical languages with optimal memory. In Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP), pages 1978–2010, Online. Association for C… find
- Jennifer Hu, Jon Gauthier, Peng Qian, Ethan Wilcox, and Roger Levy. 2020. A systematic assessment of syntactic generalization in neural language models. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 1725–1744, Online. Association for Computational… find
- Qian Huang, Eric Zelikman, Sarah Li Chen, Yuhuai Wu, Gregory Valiant, and Percy Liang. 2023. Lexinvari-ant language models. find
- Lifeng Jin, Finale Doshi-Velez, Timothy Miller, William Schuler, and Lane Schwartz. 2018. Depth-bounding is effective: Improvements and evaluation of unsupervised PCFG induction. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 2721–2731, Brussels, Bel… find
- Aravind K. Joshi. 1985. Tree adjoining grammars: How much context-sensitivity is required to provide reasonable structural descriptions?, Studies in Natural Language Processing, page 206–250. Cambridge University Press. find
- Siddharth* Karamcheti, Laurel* Orr, Jason Bolton, Tianyi Zhang, Karan Goel, Avanika Narayan, Rishi Bommasani, Deepak Narayanan, Tatsunori Hashimoto, Dan Jurafsky, Christopher D. Manning, Christopher Potts, Christopher Ré, and Percy Liang. 2021. Mistral - a journey towards reproducible language model… find
- Fred Karlsson. 2007. Constraints on multiple center-embedding of clauses. Journal of Linguistics, 43(2):365–392. find
- Amirhossein Kazemnejad, Inkit Padhi, Karthikeyan Natesan Ramamurthy, Payel Das, and Siva Reddy. 2023. The impact of positional encoding on length generalization in transformers. arXiv preprint arXiv:2305.19466. find
- Roger Levy. 2008. Expectation-based syntactic comprehension. Cognition, 106(3):1126–1177. find
- John Mansfield and Charles Kemp. 2023. The emergence of grammatical structure from inter-predictability. find
- Rebecca Marvin and Tal Linzen. 2018. Targeted syntactic evaluation of language models. In Proceedings of the 2018 Conference on Empirical Methods in Natural Language Processing, pages 1192–1202, Brussels, Belgium. Association for Computational Linguistics. find
- William Merrill. 2019. Sequential neural networks as automata. In Proceedings of the Workshop on Deep Learning and Formal Languages: Building Bridges, pages 1–13, Florence. Association for Computational Linguistics. find
- William Merrill, Gail Weiss, Yoav Goldberg, Roy Schwartz, Noah A. Smith, and Eran Yahav. 2020. A formal hierarchy of RNN architectures. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics, pages 443–459, Online. Association for Computational Linguistics. find
- Jeff Mitchell and Jeffrey Bowers. 2020. Priorless recurrent networks learn curiously. In Proceedings of the 28th International Conference on Computational Linguistics, pages 5147–5158, Barcelona, Spain (Online). International Committee on Computational Linguistics. find
- Andrea Moro, Matteo Greco, and Stefano F. Cappa. 2023. Large languages, impossible languages and human brains. Cortex, 167:82–85. find
- Shikhar Murty, Pratyusha Sharma, Jacob Andreas, and Christopher D. Manning. 2023. Pushdown layers: Encoding recursive structure in transformer language models. find
- Mariacristina Musso, Andrea Moro, Volkmar Glauche, Michel Rijntjes, Jürgen Reichenbach, Christian Büchel, and Cornelius Weiller. 2003. Broca’s area and the language instinct. Nature Neuroscience, 6(7):774–781. find
- Ryan M. Nefdt. 2024. The Philosophy of Theoretical Linguistics: A Contemporary Outlook. Cambridge University Press. find
- Isabel Papadimitriou, Richard Futrell, and Kyle Mahowald. 2022. When classifying grammatical role, BERT doesn’t care about word order... except when it matters. In Proceedings of the 60th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers), pages 636–643, Dublin,… find
- Isabel Papadimitriou and Dan Jurafsky. 2023. Injecting structural hints: Using language models to study inductive biases in language learning. find
- Thang Pham, Trung Bui, Long Mai, and Anh Nguyen. 2021. Out of order: How important is the sequential order of words in a sentence in natural language understanding tasks? In Findings of the Association for Computational Linguistics: ACL-IJCNLP 2021, pages 1145–1160, Online. Association for Computati…
- Grusha Prasad, Marten van Schijndel, and Tal Linzen. 2019. Using priming to uncover the organization of syntactic representations in neural language models. In Proceedings of the 23rd Conference on Computational Natural Language Learning (CoNLL), pages 66–76, Hong Kong, China. Association for Comput… find
- Jorge Pérez, Pablo Barceló, and Javier Marinkovic. 2021. Attention is Turing-complete. Journal of Machine Learning Research, 22(75):1–35. find
- Peng Qi, Yuhao Zhang, Yuhui Zhang, Jason Bolton, and Christopher D. Manning. 2020. Stanza: A Python natural language processing toolkit for many human languages. In Proceedings of the 58th Annual Meeting of the Association for Computational Linguistics: System Demonstrations.
- Alec Radford, Karthik Narasimhan, Tim Salimans, and Ilya Sutskever. 2018. Improving language understanding by generative pre-training. Ms, OpenAI. find
- Alec Radford, Jeff Wu, Rewon Child, David Luan, Dario Amodei, and Ilya Sutskever. 2019. Language models are unsupervised multitask learners. Ms, OpenAI. find
- Stuart M. Shieber. 1985. Evidence against the context-freeness of natural language. Linguistics and Philosophy, 8(3):333–343. find
- Koustuv Sinha, Robin Jia, Dieuwke Hupkes, Joelle Pineau, Adina Williams, and Douwe Kiela. 2021. Masked language modeling and the distributional hypothesis: Order word matters pre-training for little. In Proceedings of the 2021 Conference on Empirical Methods in Natural Language Processing, pages 288…
- Zhengxuan Wu, Atticus Geiger, Joshua Rozner, Elisa Kreiss, Hanson Lu, Thomas Icard, Christopher Potts, and Noah Goodman. 2022. Causal distillation for language models. In Proceedings of the 2022 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language… find
- Ian Tenney, Patrick Xia, Berlin Chen, Alex Wang, Adam Poliak, R. Thomas McCoy, Najoung Kim, Benjamin Van Durme, Samuel R. Bowman, Dipanjan Das, and Ellie Pavlick. 2019. What do you learn from context? Probing for sentence structure in contextualized word representations. In International Conference…
- Ashish Vaswani, Noam Shazeer, Niki Parmar, Jakob Uszkoreit, Llion Jones, Aidan N Gomez, Ł ukasz Kaiser, and Illia Polosukhin. 2017. Attention is all you need. In Advances in Neural Information Processing Systems, volume 30. Curran Associates, Inc.
- Alex Warstadt, Leshem Choshen, Aaron Mueller, Adina Williams, Ethan Wilcox, and Chengxu Zhuang. 2023. Call for papers – the BabyLM challenge: Sample-efficient pretraining on a developmentally plausible corpus. find
- Gail Weiss, Yoav Goldberg, and Eran Yahav. 2018. On the practical computational power of finite precision RNNs for language recognition. In Proceedings of the 56th Annual Meeting of the Association for Computational Linguistics (Volume 2: Short Papers), pages 740–745, Melbourne, Australia. Associati…
- Ethan Wilcox, Roger Levy, Takashi Morita, and Richard Futrell. 2018. What do RNN language models learn about filler–gap dependencies? In Proceedings of the 2018 EMNLP Workshop BlackboxNLP: Analyzing and Interpreting Neural Networks for NLP, pages 211–221, Brussels, Belgium. Association for Computati…
- Ethan Gotlieb Wilcox, Richard Futrell, and Roger Levy. 2023. Using computational models to test syntactic learnability. Linguistic Inquiry, pages 1–44. find
- Zhengxuan Wu, Karel D’Oosterlinck, Atticus Geiger, Amir Zur, and Christopher Potts. 2023a. Causal proxy models for concept-based model explanations. In Proceedings of the 40th International Conference on Machine Learning, volume 202 of Proceedings of Machine Learning Research, pages 37313–37334. PML… find
- Zhengxuan Wu, Atticus Geiger, Thomas Icard, Christopher Potts, and Noah Goodman. 2023b. Interpretability at scale: Identifying causal mechanisms in Alpaca. In Advances in Neural Information Processing Systems, volume 36, pages 78205–78226. Curran Associates, Inc.
Updated
This page in Markdown → https://md.research.elamur.ai/free/en/papers/kallini-2024-mission-impossible-language-models/