Enhancing Low-Resource Language Reasoning via High-Resource Language Feature Transfer

Minju Song, Hyeon Hwang, Junhyun Lee, Jaewoo Kang


Abstract
Large language models exhibit substantial performance variation across languages, even when solving semantically equivalent tasks. Existing analyses often treat this phenomenon as an observational disparity caused by differences in pretraining data, tokenization, or benchmark coverage. We study a complementary hypothesis: high-resource languages (HRLs) may more reliably elicit latent computations useful for task-specific (i.e. mathematical) reasoning, while lower-resource languages (LRLs) may under-activate those computations despite expressing the same task. To test this hypothesis, we introduce a mechanistic intervention framework for identifying and transferring task-relevant sparse latent features across languages. Using sparse autoencoders over residual-stream activations, we isolate features enriched in successful HRL task-specific reasoning while filtering out source-language and generic-generation features. We then construct steering directions from these features and inject them during LRL inference. The resulting interventions test whether the selected features are functionally involved in the observed reasoning gap: suppressing them should impair source-language reasoning, while activating them should partially recover target-language reasoning beyond random and non-task controls. Our framework reframes some cross-lingual reasoning gaps as failures of mechanism elicitation rather than capability absence, and offers a causally testable route to feature-mediated transfer without translation, fine-tuning, or changing the user-facing language.
Anthology ID:
2026.findings-emnlp.2262
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
48447–48461
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.2262/
DOI:
10.18653/2026.findings-emnlp.2262
Bibkey:
Cite (ACL):
Minju Song, Hyeon Hwang, Junhyun Lee, and Jaewoo Kang. 2026. Enhancing Low-Resource Language Reasoning via High-Resource Language Feature Transfer. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 48447–48461, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Enhancing Low-Resource Language Reasoning via High-Resource Language Feature Transfer (Song et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-emnlp.2262.pdf