Lost in Localization: Benchmarking Intralingual Cultural Adaptation in Large Language Models

Soumedhik Bharati, Maharaj Brahma, Maunendra Sankar Desarkar


Abstract
Cultural adaptation, rewriting text for a different cultural audience, requires more than lexical substitution. A model must decide what to change, whether each replacement is locally valid, and whether it preserves the original item’s functional role. We formalize this as function-preserving cultural transfer and introduce a dataset, a taxonomy, and an evaluation framework constructed around that principle. CulturalAdapt-6K identifies 6,000 culturally rich texts in four discourse domains, while the Cultural Rewriting and Adaptation Failure Taxonomy (CRAFT) classifies errors into five categories. To mitigate the Anglocentric priors of current models, our proposed framework anchors each culturally significant item in a Wikidata-linked function frame, capturing its contextual role rather than surface denotation. Across 191,968 adaptations by eight instruction-tuned LLMs, we find that the models that substitute the most are not the ones that substitute best. High localization increases failure exposure, while conservative retention increases validity scores, yet both converge to the same overall functional quality. Current generative models can certainly dress text in a target culture’s vocabulary but ultimately cannot reliably preserve the contextual roles the vocabulary is meant to serve.
Anthology ID:
2026.findings-emnlp.1658
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
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SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
35338–35358
Language:
URL:
https://aclanthology.org/2026.findings-emnlp.1658/
DOI:
Bibkey:
Cite (ACL):
Soumedhik Bharati, Maharaj Brahma, and Maunendra Sankar Desarkar. 2026. Lost in Localization: Benchmarking Intralingual Cultural Adaptation in Large Language Models. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 35338–35358, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Lost in Localization: Benchmarking Intralingual Cultural Adaptation in Large Language Models (Bharati et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.1658.pdf